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Revision 439674 of "Climate change mitigation" on testwiki{{short description|Actions to limit the magnitude of climate change and its impact on human activities}}
[[File:Global Energy Consumption.svg|thumb|upright=1.35|right|Coal, oil, and natural gas remain the primary global energy sources even as [[Renewable energy|renewables]] have begun rapidly increasing.<ref>{{harvnb|Friedlingstein|Jones|O'Sullivan|Andrew|2019}}.</ref>]]
[[File:Climate Change Performance Index.svg|thumb|upright=1.35|right|The [[Climate Change Performance Index]] ranks countries by greenhouse gas emissions (40% of score), renewable energy (20%), energy use (20%), and climate policy (20%).]]
'''Climate change mitigation''' consists of actions to limit the magnitude or rate of [[global warming]] and [[Effects of global warming|its related effects]].<ref>{{citation
|title=Contribution of Working Group III to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change, 2007
|at=[http://www.ipcc.ch/publications_and_data/ar4/wg3/en/ch3s3-5.html 3.5 Interaction between mitigation and adaptation, in the light of climate change impacts and decision-making under long-term uncertainty]
|author=Fisher, B.S.
|chapter=Ch. 3: Issues related to mitigation in the long-term context
|display-authors=etal}}, in {{harvnb|IPCC AR4 WG3|2007}}</ref> This generally involves reductions in human emissions of [[greenhouse gas]]es (GHGs).<ref name="ipcc mitigation options">{{citation
|title=Climate Change 2007: Working Group III: Mitigation of Climate Change
|at=[http://www.ipcc.ch/publications_and_data/ar4/wg3/en/spmsspm-c.html Table SPM.3, C. Mitigation in the short and medium term (until 2030)]
|chapter=Summary for policymakers
|chapter-url=http://www.ipcc.ch/publications_and_data/ar4/wg3/en/spm.html
|author=IPCC
}}, in {{harvnb|IPCC AR4 WG3|2007}}</ref>
[[Fossil fuel|Fossil fuels]] account for about 70% of GHG emissions.<ref>{{cite web|title=GHG Emissions|url=https://www.climatewatchdata.org/ghg-emissions?breakBy=sector&chartType=percentage|publisher=CAIT Climate Data Explorer|accessdate=29 January 2020}}</ref> The main challenge is their substitution with [[low-carbon power|low-carbon energy]] sources. Due to massive price drops, [[wind power]] and solar [[photovoltaics]] (PV) are increasingly out-competing oil, gas and coal<ref>{{cite web|title=Falling Renewable Power Costs Open Door to Greater Climate Ambition|url=https://www.irena.org/newsroom/pressreleases/2019/May/Falling-Renewable-Power-Costs-Open-Door-to-Greater-Climate-Ambition|publisher=IRENA|accessdate=29 January 2020}}</ref> but require [[energy storage]] and extended [[electrical grid|electrical grids]].
Mitigation may also be achieved by increasing the capacity of [[carbon sink]]s, for example through [[reforestation]].<ref name="ipcc mitigation options"/>
Other examples of mitigation include reducing energy demand by increasing [[efficient energy use|energy efficiency]] and [[Carbon dioxide removal|removing carbon dioxide]] from Earth's atmosphere.<ref name="ipcc mitigation options"/><ref>{{citation
|chapter=Sec 5.5 Technology flows and development
|title=Climate Change 2007: Synthesis Report
|chapter-url=http://www.ipcc.ch/publications_and_data/ar4/syr/en/mains5-5.html
}}, in {{harvnb|IPCC AR4 SYR|2007|p=68}}</ref> [[Climate engineering]] is often controversial but might have to be used in addition to reducing GHG emissions.<ref>{{Cite web|url=https://www.sciencedaily.com/releases/2019/10/191028164351.htm|title=Climate engineering: International meeting reveals tensions: Lack of transparency impedes collaboration, excludes developing world|website=ScienceDaily|language=en|access-date=2020-04-02}}</ref>
Almost all countries are parties to the [[United Nations Framework Convention on Climate Change]] (UNFCCC).<ref>{{citation
|title=Introduction to the Convention
|author=UNFCCC
|url=http://unfccc.int/key_steps/the_convention/items/6036.php
|publisher=UNFCCC
|date=5 March 2013
}}</ref> The ultimate objective of the UNFCCC is to stabilize atmospheric concentrations of GHGs at a level that would prevent dangerous human interference with the climate system.<ref>{{citation
|title=Full Text of the Convention, Article 2: Objectives
|author=UNFCCC
|url=http://unfccc.int/essential_background/convention/background/items/1353.php
|publisher=UNFCCC
|date=2002
}}</ref>
In 2010, Parties to the UNFCCC agreed that future global warming should be limited to below {{convert|2|C-change|F-change|1}} relative to the pre-[[Industrial Revolution|industrial]] level.<ref>{{citation
|date=15 March 2011
|author=UNFCCC. Conference of the Parties (COP)
|title=Report of the Conference of the Parties on its sixteenth session, held in Cancun from 29 November to 10 December 2010. Addendum. Part two: Action taken by the Conference of the Parties at its sixteenth session
|publisher=United Nations
|location=Geneva, Switzerland
|url=http://unfccc.int/resource/docs/2010/cop16/eng/07a01.pdf#page=2
}}, p. 3, paragraph 4. Document [http://unfccc.int/documentation/documents/advanced_search/items/6911.php?priref=600006173 available] in UN languages and text format.</ref> With the [[Paris Agreement]] of 2015 this was confirmed.
With the [[Special Report on Global Warming of 1.5 °C]], the [[International Panel on Climate Change]] has emphasized the benefits of keeping global warming below this level, suggesting a global collective effort that may be guided by the 2015 United Nations Sustainable Development Goals.<ref>{{Harvnb|IPCC SR15 Technical Summary|2018|p=31}}</ref> Emissions pathways with no or limited overshoot would require rapid and far-reaching transitions in energy, land, urban and infrastructure including transport and buildings, and industrial systems.<ref>{{Harvnb|IPCC SR15 Summary for Policymakers|2018|p=15}}</ref>
The current trajectory of global greenhouse gas emissions does not appear to be consistent with limiting global warming to below 1.5 or 2 °C.<ref>{{cite news |last1=Harvey |first1=Fiona |title=UN calls for push to cut greenhouse gas levels to avoid climate chaos |url=https://www.theguardian.com/environment/2019/nov/26/united-nations-global-effort-cut-emissions-stop-climate-chaos-2030 |accessdate=27 November 2019 |agency=The Guardian |date=26 November 2019}}</ref><ref>{{cite web |title=Cut Global Emissions by 7.6 Percent Every Year for Next Decade to Meet 1.5°C Paris Target - UN Report |url=https://unfccc.int/news/cut-global-emissions-by-76-percent-every-year-for-next-decade-to-meet-15degc-paris-target-un-report |website=United Nations Framework Convention on Climate Change |publisher=United Nations |accessdate=27 November 2019}}</ref><ref>Victor, D., ''et al.'', Executive summary, in: [http://report.mitigation2014.org/drafts/final-draft-postplenary/ipcc_wg3_ar5_final-draft_postplenary_chapter1.pdf Chapter 1: Introductory Chapter], p. 4 (archived [https://web.archive.org/web/20140703063821/http://report.mitigation2014.org/drafts/final-draft-postplenary/ipcc_wg3_ar5_final-draft_postplenary_chapter1.pdf 3 July 2014)], in {{harvnb|IPCC AR5 WG3|2014}}</ref> However, globally the benefits of keeping warming under 2 °C exceed the costs.<ref>{{harvnb|Sampedro|Smith|Arto|González-Eguino|2020}}.</ref>
{{TOC limit|3}}
==Greenhouse gas concentrations and stabilization==
{{See also|Greenhouse gas#Removal from the atmosphere and global warming potential|Carbon dioxide in Earth's atmosphere}}
{{Multiple image
|direction=vertical
|align=right
|image1=Stabilizing carbon dioxide emissions at their present level will not stabilize its concentration in the atmosphere.png
|image2=Stabilizing the atmospheric concentration of carbon dioxide at a constant level would require emissions to be effectively eliminated.png
|alt1=refer to caption and adjacent text
|alt2=refer to caption and adjacent text
|width=320
|caption1=Stabilizing CO<sub>2</sub> emissions at their present level would not stabilize its concentration in the atmosphere.<ref name="meehl stabilizing ghg concentrations">{{citation
|title=Climate Change 2007: Working Group I: The Physical Science Basis
|author=Meehl, G.A.
|at=[http://www.ipcc.ch/publications_and_data/ar4/wg1/en/faq-10-3.html FAQ 10.3: If Emissions of Greenhouse Gases are Reduced, How Quickly do Their Concentrations in the Atmosphere Decrease?]
|chapter=Ch. 10: Global Climate Projections
|chapter-url=http://www.ipcc.ch/publications_and_data/ar4/wg1/en/ch10.html
|display-authors=etal}}, in {{harvnb|IPCC AR4 WG1|2007|pp=824–825}}</ref>
|caption2=Stabilizing the atmospheric concentration of CO<sub>2</sub> at a constant level would require emissions to be effectively eliminated.<ref name="meehl stabilizing ghg concentrations"/>}}
The UNFCCC aims to stabilize greenhouse gas (GHG) concentrations in the atmosphere at a level where [[climate change and ecosystems|ecosystems]] can adapt naturally to climate change, [[climate change and agriculture|food production]] is not threatened, and [[economics of global warming|economic development]] can proceed in a sustainable fashion.<ref>
{{cite book
|year=2007
|author=Rogner, H.-H.
|contribution=1.2 Ultimate objective of the UNFCCC
|title=Introduction
|series=Climate Change 2007: Mitigation. Contribution of Working Group III to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change
|editor=B. Metz
|display-editors=etal
|url=http://www.ipcc.ch/publications_and_data/ar4/wg3/en/ch1s1-2.html
|publisher=Print version: Cambridge University Press, Cambridge, United Kingdom and New York, NY, USA. This version: IPCC website
|accessdate=2011-06-07
|display-authors=etal
|archive-url=https://web.archive.org/web/20140923012655/http://www.ipcc.ch/publications_and_data/ar4/wg3/en/ch1s1-2.html
|archive-date=2014-09-23
|url-status=dead
}}
</ref>
Currently human activities are adding CO<sub>2</sub> to the atmosphere faster than natural processes can remove it.<ref name="meehl stabilizing ghg concentrations"/>
According to a 2011 US study, stabilizing atmospheric CO<sub>2</sub> concentrations would require anthropogenic CO<sub>2</sub> emissions to be reduced by 80% relative to the peak emissions level.<ref name="us nrc co2 stabilization">[http://www.nap.edu/openbook.php?record_id=12877&page=21 2. Stabilization and Climate Change of the Next Few Decades and Next Several Centuries, p. 21], in: [http://www.nap.edu/openbook.php?record_id=12877&page=11 Summary], in {{harvnb|US NRC|2011}}</ref>{{Update inline|date=April 2020|reason=}}
The IPCC works with the concept of a fixed carbon [[emissions budget]]. If emissions remain on the current level of 42 Gt{{CO2}}, the carbon budget for 1.5°C could be exhausted in 2028.<ref>{{Harvnb|IPCC SR15 Ch2|2018|p=96}}</ref>
The rise in temperature to that level would occur with some delay between 2030 and 2052.<ref>{{Harvnb|IPCC SR15 Ch1|2018|p=66}}</ref>. Even if it was possible to achieve negative emissions in the future, 1.5°C must not be exceeded at any time to avoid the loss of ecosystems.<ref>{{harvnb|IPCC SR15 Summary for Policymakers|2018|p=5}}</ref>
After leaving room for emissions for food production for 9 billion people and to keep the global temperature rise below 2 °C, emissions from energy production and transport will have to peak almost immediately in the developed world and decline at about 10% each year until zero emissions are reached around 2030.<ref>{{cite journal|title=Beyond 'dangerous' climate change: emission scenarios for a new world|journal=Philosophical Transactions of the Royal Society A|first1=Kevin|last1=Anderson|first2=Alice|last2=Bows|date=13 January 2011|volume=369|issue=1934|pages=20–44|doi=10.1098/rsta.2010.0290|pmid=21115511|bibcode=2011RSPTA.369...20A|doi-access=free}}</ref><ref>{{cite journal|title=A new paradigm for climate change|journal=Nature Climate Change|first1=Kevin|last1=Anderson|first2=Alice|last2=Bows|s2cid=84963926|volume=2|issue=9|pages=639–40|doi=10.1038/nclimate1646|year=2012|bibcode=2012NatCC...2..639A}}</ref><ref>Anderson K. (2012). Real clothes for the Emperor: Facing the challenges of climate change. The Cabot annual lecture, Univ. of Bristol. [https://www.youtube.com/watch?v=RInrvSjW90U&feature=player_embedded Video], [http://www.bris.ac.uk/cabot/documents/anderson-transcript.pdf Transcript]</ref><ref>[http://www.tyndall.ac.uk/radical-emission-reduction-conference-10-11-december-2013-register-here The Radical Emission Reduction Conference: 10–11 December 2013] {{webarchive|url=https://web.archive.org/web/20141027232316/http://www.tyndall.ac.uk/radical-emission-reduction-conference-10-11-december-2013-register-here |date=27 October 2014 }}, sponsored by the [[Tyndall Centre]]. [http://tyndall.ac.uk/communication/news-archive/2013/radical-emissions-reduction-conference-videos-now-online Video proceedings] {{Webarchive|url=https://web.archive.org/web/20170324225944/http://tyndall.ac.uk/communication/news-archive/2013/radical-emissions-reduction-conference-videos-now-online |date=2017-03-24 }} on-line.</ref>{{Update inline|date=April 2020|reason=}}
===Sources of greenhouse gas emissions===
{{Pie chart
| thumb =right
| caption =''GHG emissions 2018''<br>without land-use change<br>using 100 year GWP<ref name="Trends">{{harvnb|Olivier|Peters|2020|p=4}}</ref>
| label1 ={{CO2}} by fossil fuel
| value1 =72
| color1 =black
| label2 =CH<sub>4</sub> methane
| color2 =brown
| value2 =19
| label3 ={{chem|N|2|O}} nitrous oxide
| value3 =6
| color3 =grey
| label4 =Fluorinated gases
| value4 =3
| color4 =blue
}}
{{Pie chart
| thumb =right
| caption ={{CO2}} emissions by fuel type<ref name="gcb">{{harvnb|Global Carbon Budget|2019}}</ref>
| label1 =coal
| value1 =40
| color1 =#602200
| label2 =oil
| value2 =34
| color2 =#333333
| label3 =gas
| value3 =21
| color3 =#888800
| label4 =cement
| value4 =4
| color4 =#888888
| label5 =flaring
| value5 =1
| color5 =#000050
}}
With the [[Kyoto Protocol]], the reduction of almost all anthropogenic greenhouse gases has been addressed.<ref>{{cite journal
|title=The Economics of the Kyoto Protocol
|author=Grubb, M.
|date=July–September 2003
|journal=World Economics
|volume=4
|issue=3
|pages=146–47
|url=http://www.econ.cam.ac.uk/rstaff/grubb/publications/J36.pdf
|accessdate=2010-03-25
|url-status=dead
|archiveurl=https://web.archive.org/web/20110717152152/http://www.econ.cam.ac.uk/rstaff/grubb/publications/J36.pdf
|archivedate=2011-07-17
}}</ref> These gases are CO<sub>2</sub>, [[methane]] (CH<sub>4</sub>), [[nitrous oxide]] (N<sub>2</sub>O) and [[fluorinated gases]] (F-Gases): the [[halocarbon|hydrofluorocarbons]] (HFC), perfluorocarbons (PFC), and [[sulfur hexafluoride]] (SF<sub>6</sub>).
Their [[global warming potential]] (GWP) depends on their lifetime in the atmosphere. Methane has a relatively short atmospheric lifetime of about 12 years but a high immediate impact.<ref>{{cite web|title= Methane vs. Carbon Dioxide: A Greenhouse Gas Showdown|url= http://www.onegreenplanet.org/animalsandnature/methane-vs-carbon-dioxide-a-greenhouse-gas-showdown/|website= One Green Planet|date= 30 September 2014|accessdate= 2015-11-15}}</ref> For methane, a reduction of about 30% below current emission levels would lead to a stabilization in its atmospheric concentration, while for N<sub>2</sub>O, an emissions reduction of more than 50% would be required.<ref name="meehl stabilizing ghg concentrations"/> Estatimatons largely depend on the ability of oceans and land sinks to absorb GHGs. The risk of feedback effects in global warming leads to high uncertainties in the determination of GWP values.
====Carbon dioxide ({{CO2}})====
* '''Fossil fuel''': [[oil]], [[gas]] and [[coal]] are the major driver of anthropogenic global warming with annual emissions of 34.6 Gt{{CO2}} in 2018.<ref name="gcb"/>
* '''[[cement]]''' production is estimated 1.5 Gt{{CO2}}<ref name="gcb"/>
* '''Land-use change''' (LUC) is the imbalance of [[deforestation]] and [[reforestation]]. Estimations are very uncertain at 3.8 Gt{{CO2}}<ref name="Trends"/>. [[Wildfire|Wildfires]] cause emissions of about 7 Gt{{CO2}}<ref>{{cite news|url=https://www.bloomberg.com/graphics/2020-fire-emissions/|title=Measuring the Carbon-Dioxide Cost of Last Year's Worldwide Wildfires|publisher=Bloomberg L.P.|first1=Laura Millan|last1=Lombrana|first2=Hayley|last2=Warren|first3=Akshat|last3=Rathi|year=2020}}</ref><ref>{{cite report|url=http://www.globalfiredata.org/_plots/annual_emissions.pdf|title=Global fire annual emissions|publisher=Global Fire Emissions Database}} </ref>
* '''[[Gas flare|Flaring]]''': In crude oil production vast amounts of associated gas are commonly flared as waste or unusable gas.
====Methane (CH<sub>4</sub>)====
* '''Fossil fuel''' (33%) also accounts for most of the methane emissions including gas distribution, leakages and [[gas venting]].<ref name="Trends2">{{harvnb|Olivier|Peters|2020|p=12}}</ref>
* '''Cattle''' (21%) account for two thirds of the methane emitted by livestock, followed by buffalo, sheep and goats<ref>{{harvnb|Olivier|Peters|2020|p=23}}</ref>
* '''Human waste and waste water''' (21%): When biomass waste in landfills and organic substances in domestic and industrial waste water are decomposed by bacteria in anaerobic conditions, substantial amounts of methane are generated. <ref name="Trends2"/>
* '''Rice cultivation''' (10%) on flooded rice fields is another agricultural source, where anaerobic decomposition of organic material produces methane. <ref name="Trends2"/>
====Nitrous oxide ({{chem|N|2|O}})====
* Most emissions by '''agriculture''', especially '''meat production''': cattle (droppings on pasture), fertilizers, animal manure<ref name="Trends2"/>
====F-Gases====
* Switchgear in the power sector, semi-conducture manufacture, aluminium production and a large unknown source of SF<sub>6</sub><ref>{{harvnb|Olivier|Peters|2020|p=38}}</ref>
===Projections===
Projections of future greenhouse gas emissions are highly uncertain.<ref>{{citation
|title=Contribution of Working Group III to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change, 2007
|chapter=Ch 3: Issues related to mitigation in the long-term context
|chapter-url=http://www.ipcc.ch/publications_and_data/ar4/wg3/en/ch3.html
|author=Fisher, B.S.
|at=[http://www.ipcc.ch/publications_and_data/ar4/wg3/en/ch3s3-1.html Sec 3.1 Emissions scenarios]
|display-authors=etal}}, in {{harvnb|IPCC AR4 WG3|2007}}</ref> In the absence of policies to mitigate climate change, GHG emissions could rise significantly over the 21st century.<ref name="rogner article 2">{{citation
|title=Contribution of Working Group III to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change, 2007
|author=Rogner, H.-H.
|chapter=Ch 1: Introduction
|at=[http://www.ipcc.ch/publications_and_data/ar4/wg3/en/ch1s1-3-2-4.html Sec 1.3.2.4 Total GHG emissions]
|chapter-url=http://www.ipcc.ch/publications_and_data/ar4/wg3/en/ch1.html
|display-authors=etal}}, in {{harvnb|IPCC AR4 WG3|2007|p=111}}</ref>
Current scientific projections warn of a 4.5 degree temperature rise in decades. <ref name="Trajectories of the Earth System in the Anthropocene">{{cite journal |last1=Steffen |first1=Will |last2=Rockström |first2=Johan |last3=Richardson |first3=Katherine |last4=M. Lenton |first4=Timothy |last5=Folke |first5=Carl |last6=Liverman |first6=Diana |last7=P. Summerhayes |first7=Colin |last8=D. Barnosky |first8=Anthony |last9=E. Cornell |first9=Sarah |last10=Crucifix |first10=Michel |last11=F. Donges |first11=Jonathan |last12=Fetzer |first12=Ingo |last13=J. Lade |first13=Steven |last14=Scheffer |first14=Marten |last15=Winkelmann |first15=Ricarda |last16=Hans Joachim Schellnhuber |first16=Hans |title=Trajectories of the Earth System in the Anthropocene |journal=Proceedings of the National Academy of Sciences |volume=115 |issue=33 |pages=8252–8259 |date=August 6, 2018 |doi=10.1073/pnas.1810141115 |pmid=30082409 |pmc=6099852 |bibcode=2018PNAS..115.8252S }}</ref>
===Methods and means===
{{quote box|quote=We cannot be radical enough in dealing with those issues that face us at the moment. The question is what is practically possible.|author=[[David Attenborough]]|source=in testimony to the UK [[House of Commons of the United Kingdom|House of Commons]] [[Business, Energy and Industrial Strategy Committee]].<ref>{{Cite AV media |url=https://www.theguardian.com/tv-and-radio/video/2019/jul/09/we-cannot-be-radical-enough-david-attenborough-climate-emergency-video |title='We cannot be radical enough': Attenborough on climate crisis action |date=2019-07-09 |language=en-GB |access-date=2019-09-02 |issn=0261-3077}}</ref>}}
As the cost of reducing GHG emissions in the [[electricity]] sector appears to be lower than in other sectors, such as in the [[transportation]] sector, the electricity sector may deliver the largest proportional carbon reductions under an economically efficient climate policy.<ref name=issues>[http://www.issues.org/23.3/apt.html Issues in Science] {{Webarchive|url=https://web.archive.org/web/20130927013232/http://www.issues.org/23.3/apt.html |date=2013-09-27 }} & Technology Online; "Promoting Low-Carbon Electricity Production"</ref>
Economic tools can be useful in designing climate change mitigation policies.<ref name="AR5-WG3-Chap3">
{{citation
|chapter=Social, Economic, and Ethical Concepts and Methods, Executive Summary
|title=Climate Change 2014: Mitigation of Climate Change
|chapter-url=http://ipcc.ch/pdf/assessment-report/ar5/wg3/ipcc_wg3_ar5_chapter3.pdf}}, in {{harvnb|IPCC AR5 WG3|2014|p=211}}
</ref> Abolishing fossil fuel subsidies is very important but must be done carefully to avoid making poor people poorer.<ref>{{Cite web|url=https://www.iisd.org/blog/lesson-ecuador-fossil-fuel-subsidies|title=How Reforming Fossil Fuel Subsidies Can Go Wrong: A lesson from Ecuador|website=IISD|language=en|access-date=2019-11-11}}</ref>
Other frequently discussed means include efficiency, public transport, increasing [[fuel economy in automobiles]] (which includes the use of [[hybrid vehicle|electric hybrids]]), charging [[plug-in hybrid]]s and [[electric car]]s by [[low-carbon power|low-carbon electricity]], making [[individual and political action on climate change|individual changes]],<ref>{{citation
|chapter=Sec 4.3 Mitigation options
|title=Climate Change 2007: Synthesis Report
|chapter-url=http://www.ipcc.ch/publications_and_data/ar4/syr/en/mains4-3.html
}}, in {{harvnb|IPCC AR4 SYR|2007}}</ref> and [[business action on climate change|changing business practices]]. Replacing gasoline and diesel vehicles with electric means their emissions would be displaced away from street level, where they cause illness.
Another consideration is how future [[socioeconomic development]] proceeds.<ref>{{citation
|title=Contribution of Working Group III to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change, 2007
|chapter=Ch 12: Sustainable Development and mitigation
|chapter-url=http://www.ipcc.ch/publications_and_data/ar4/wg3/en/ch12.html
|author=Sathaye, J.
|at=[http://www.ipcc.ch/publications_and_data/ar4/wg3/en/ch12s12-2-1-1.html Sec 12.2.1.1 Development paths as well as climate policies determine GHG emissions]
|display-authors=etal}}, in {{harvnb|IPCC AR4 WG3|2007|pp=701–703}}</ref>
==Fossil fuel substitution==
{{main|Fossil fuel phase-out}}
As most greenhouse gas emissions are due to fossil fuels, rapidly phasing out oil, gas and coal is critical.<ref>{{Cite news|url=https://www.nytimes.com/2019/10/07/business/energy-environment/climate-energy-experts-debate.html|title=Climate and Energy Experts Debate How to Respond to a Warming World|last=Times|first=The New York|date=2019-10-07|work=The New York Times|access-date=2019-11-10|language=en-US|issn=0362-4331}}</ref> The incentive to use [[100% renewable energy]] has been created by global warming and other ecological as well as economic concerns.<ref name=pg11>{{cite web |url=http://www.renewableenergyworld.com/rea/news/article/2013/04/100-percent-renewable-vision-building?amp;buffer_share=fdc06 |title=100 Percent Renewable Vision Building |author=Paul Gipe |date=4 April 2013 |website=Renewable Energy World}}</ref> According to the IPCC, there are few fundamental technological limits to integrating a portfolio of renewable energy technologies to meet most of total global energy demand.<ref name="IPCC 2011 17">{{cite web|url=http://srren.ipcc-wg3.de/report/IPCC_SRREN_SPM.pdf |title=Special Report on Renewable Energy Sources and Climate Change Mitigation |author=IPCC |year=2011 |website=Cambridge University Press, Cambridge, United Kingdom and New York, NY|page=17 |url-status=dead |archiveurl=https://web.archive.org/web/20140111081913/http://srren.ipcc-wg3.de/report/IPCC_SRREN_SPM.pdf |archivedate=2014-01-11 }}</ref>
The global [[primary energy]] demand was 161,320 TWh in 2018.<ref name="IEA GECO">{{harvnb|Global Energy & CO2 Status Report|2019}}</ref> This refers to electricity, transport and heating including all losses.
The primary energy demand in a low-carbon economy is difficult to determine. In transport and electricity production, fossil fuel usage has a low efficiency of less than 50%. Motors of vehicles produce a lot of heat which is wasted. Electrification of all sectors and switching to renewable energy can lower the primary energy demand significantly. On the other hand, storage requirements and reconversion to electricity lower the efficiency of renewable energy.
In 2018, biomass and waste was listed with a share of 10% of primary energy, hydro power with 3%. Wind, solar energy and other renewables were at 2%.<ref name="IEA GECO"/>
===Low-carbon energy sources===
{{See also|Low-carbon economy|Renewable energy|Renewable energy commercialization|Renewable energy debate|Emission intensity#Energy sources emission intensity per unit of energy generated}}
Wind and sun can be sources for large amounts of low-carbon energy at competitive production costs. Solar PV module prices fell by around 80% in the 2010s, and wind turbine prices by 30–40%.<ref>{{Cite web | url=https://www.irena.org/costs |title = Costs (of renewable energy)|accessdate=27 March 2020}}</ref> But even in combination, generation of [[variable renewable energy]] fluctuates a lot. This can be tackled by extending [[super grid|grids]] over large areas with a sufficient capacity or by using [[energy storage]].
According to the [[International Renewable Energy Agency]] (IRENA), the deployment of [[renewable energy]] would have to be accelerated six-fold though to stay under the 2 °C target. <ref>{{cite web|title=Global Energy Transformation: A Roadmap to 2050 (2019 edition)|url=https://www.irena.org/-/media/Files/IRENA/Agency/Publication/2019/Apr/IRENA_Global_Energy_Transformation_2019.pdf|publisher=IRENA|accessdate=29 January 2020}}</ref>
[[Load management]] of industrial energy consumption can help to balance the production of renewable energy production and its demand.
Electricity production by [[biogas]] and [[hydro power]] can [[Load following power plant|follow the energy demand]].
====Solar energy====
{{main|Solar energy}}
[[File:12-05-08 AS1.JPG|thumb|right|The 150 MW [[Andasol solar power station]] is a commercial [[parabolic trough]] [[solar thermal]] power plant, located in [[Renewable energy in Spain|Spain]]. The Andasol plant uses tanks of molten salt to store solar energy so that it can continue generating electricity for 7.5 hours after the sun has stopped shining.<ref>{{cite journal |url= |title=Saving for a rainy day |author=Edwin Cartlidge |date=18 November 2011 |journal=Science |volume=334 |issue=6058 |pages=922–24|doi=10.1126/science.334.6058.922 |pmid=22096185 |bibcode=2011Sci...334..922C }}</ref>]]
*Solar [[photovoltaics]] has become the cheapest way to produce electric energy in many regions of the world, with production costs down to 0.015 - 0.02 US$/KWh in desert regions.<ref>{{cite press release|title=KAHRAMAA and Siraj Energy Sign Agreements for Al-Kharsaah Solar PV Power Plant |url=https://www.km.qa/MediaCenter/pages/NewsDetails.aspx?ItemID=327 |publisher=Qatar General Electricity & Water Corporation “KAHRAMAA” |accessdate=26 January 2020}}</ref> The [[growth of photovoltaics]] is exponential and has doubled every three years since the 1990s.
*A different technology is [[concentrated solar power]] (CSP) using mirrors or lenses to concentrate a large area of sunlight onto a receiver. With CSP, the energy can be saved up for a few hours. Prices in Chile are expected to fall below 0.05 US$/KWh in 2020.<ref>{{cite web|title=Solar Thermal could fall to 45 Euros in 2020|url=http://helioscsp.com/the-solar-thermal-could-fall-to-45-euros-mwh-in-2020-for-some-concentrated-solar-power-projects|publisher=HeliosCSP|accessdate=24 March 2020}}</ref>
*[[Solar water heating]] makes an important and growing contribution in many countries, most notably in China, which now has 70 percent of the global total (180 GWth).{{Citation needed|date=February 2020}} Worldwide, total installed solar water heating systems meet a portion of the water heating needs of over 70 million households.{{Citation needed|date=February 2020}}
====Wind power====
{{main|wind power}}
[[File:Shepherds Flat Wind Farm 2011.jpg|thumb |The [[Shepherds Flat Wind Farm]] is an 845 [[megawatt]] (MW) [[nameplate capacity]], wind farm in the US state of [[Oregon]], each turbine is a nameplate 2 or 2.5 MW electricity generator.]]
Regions in the higher northern and southern latitudes have the highest potential for wind power.<ref>{{cite web|url=http://science.globalwindatlas.info/datasets.html|title=Global Wind Atlas|publisher=DTU Technical University of Denmark|accessdate=28 March 2020}}</ref>
Installed capacity has reached 650 GW in 2019. [[Offshore wind power]] currently has a share of about 10% of new installations.<ref>{{cite web|url=https://gwec.net/global-wind-report-2019/|title=Golbal Wind Report 2019|date=19 March 2020|publisher=Global Wind Energy Council|accessdate=28 March 2020}}</ref> Offshore [[wind farms]] are more expensive but the units deliver more energy per installed capacity with less fluctuations.
====Hydro Power====
{{main|Hydropower}}
[[File:ThreeGorgesDam-China2009.jpg|thumb |The 22,500 [[megawatt|MW]] [[nameplate capacity]] [[Three Gorges Dam]] in the [[People's Republic of China]], the largest hydroelectric power station in the world.]]
[[Hydroelectricity]] plays a leading role in countries like Brazil, Norway and China:<ref name="BP">{{cite web|url=https://www.bp.com/content/dam/bp/business-sites/en/global/corporate/pdfs/energy-economics/statistical-review/bp-stats-review-2019-full-report.pdf|title=BP Statistical Review 2019|accessdate=28 March 2020}}</ref> but there are geographical limits and environmental issues.<ref>{{cite web|title=Large hydropower dams not sustainable in the developing world|url=https://www.bbc.com/news/science-environment-46098118 |publisher=BBC|accessdate= 27 March 2020}}</ref>
[[Tidal power]] can be used in coastal regions.
====Bioenergy====
{{main|Biomass}}
[[Biogas]] plants can provide [[Dispatchable generation|dispatchable electricity generation]], and heat when needed.<ref>{{cite web|title=From baseload to peak|url=https://www.irena.org/-/media/Files/IRENA/Agency/Publication/2015/IRENA_Baseload_to_Peak_2015.pdf|publisher=IRENA|accessdate=27 March 2020}}</ref> A common concept is the co-fermentation of energy crops mixed with manure in agriculture.
Burning plant-derived [[biomass]] releases {{CO2}}, but it has still been classified as a renewable energy source in the EU and UN legal frameworks because photosynthesis cycles the {{CO2}} back into new crops. How a fuel is produced, transported and processed has a significant impact on lifecycle emissions. Transporting fuels over long distances and excessive use of nitrogen fertilisers can reduce the emissions savings made by the same fuel compared to natural gas by between 15 and 50 per cent.<ref>{{cite web|title=Biomass - Carbon sink or carbon sinner|url=https://fcrn.org.uk/sites/default/files/Biomass__carbon_sink_or_carbon_sinner_summary_report.pdf|publisher=UK environment agency|accessdate=27 March 2020}}</ref> Renewable [[biofuel]]s are starting to be used in aviation.
====Nuclear power====
In most 1.5 °C pathways [[nuclear power]] increases its share.<ref>{{Harvnb|IPCC SR15 Ch2|2018|p=131}}</ref> The main{{Citation needed|date=April 2020|reason=I thought new nuclear was supposed to be flexible}} advantage is the ability to deliver large amounts of base load. It has been repeatedly classified as a climate change mitigation technology.<ref>{{cite web|title=Ramp up nuclear power to beat climate change, says UN nuclear chief|url=https://news.un.org/en/story/2019/10/1048732|publisher=UN|accessdate=1 February 2020}}</ref>
On the other hand, nuclear power comes with environmental risks which could outweigh the benefits. Apart from [[Nuclear and radiation accidents and incidents|nuclear accidents]], the disposal of [[radioactive waste]] can cause damage and costs [[radioactive waste#Fuel_composition_and_long_term_radioactivity|over more than one million years]]. Separated [[plutonium]] could be used for nuclear weapons. <ref>{{cite web|title=Nuclear Reprocessing: Dangerous, Dirty, and Expensive|url=https://www.ucsusa.org/resources/nuclear-reprocessing-dangerous-dirty-and-expensive|publisher=Union of Concerned Scientists|accessdate=26 January 2020}}</ref><ref>{{cite web|title=Is nuclear power the answer to climate change?|url=https://wiseinternational.org/nuclear-energy/nuclear-power-answer-climate-change|publisher=World Information Service on Energy|accessdate=1 February 2020}}</ref> Public opinion about nuclear power varies widely between countries.<ref>{{harvnb|Gallup International|2011|pp=9–10}}</ref><ref>{{harvnb|Ipsos|2011|p=4}}</ref>
{{As of|2019}} the cost of extending [[nuclear power]] plant lifetimes is competitive with other electricity generation technologies, including new solar and wind projects.<ref name=IEA2019>{{Cite web|url=https://www.iea.org/newsroom/news/2019/may/steep-decline-in-nuclear-power-would-threaten-energy-security-and-climate-goals.html|title=May: Steep decline in nuclear power would threaten energy security and climate goals|website=www.iea.org|access-date=2019-07-08}}</ref>
New projects are reported to be highly dependent on public subsidies.<ref>{{cite report|title=It's Official: The United Kingdom is to subsidize nuclear power, but at what cost? |url=https://www.iisd.org/library/its-official-united-kingdom-subsidize-nuclear-power-what-cost|publisher=[[International Institute for Sustainable Development]]|accessdate=29 March 2020}}</ref>
[[Nuclear fusion]] research, in the form of the [[International Thermonuclear Experimental Reactor]] is underway but fusion is not likely to be commercially widespread before 2050.<ref name="ITERorg">{{cite web |website=The ITER Project |title=Beyond ITER |publisher=Information Services, Princeton Plasma Physics Laboratory |url=http://www.iter.org/Future-beyond.htm |accessdate=5 February 2011 |archiveurl=https://web.archive.org/web/20061107220145/http://www.iter.org/Future-beyond.htm |archivedate=7 November 2006}} – Projected fusion power timeline</ref>
====Carbon neutral and negative fuels====
Fossil fuel may be phased-out with [[carbon-neutral fuel|carbon-neutral and carbon-negative]] pipeline and transportation fuels created with [[power to gas]] and [[gas to liquids]] technologies.<ref>{{cite web|last1=Dodge|first1=Edward|title=Power-to-Gas Enables Massive Energy Storage|url=http://theenergycollective.com/ed-dodge/2166976/power-gas-enables-massive-energy-storage|website=TheEnergyCollective.com|accessdate=25 May 2015|date=December 6, 2014}}</ref><ref>{{cite news|last1=Scott|first1=Mark|title=Energy for a Rainy Day, or a Windless One|url=https://www.nytimes.com/2014/10/08/business/energy-for-a-rainy-day-or-a-windless-one.html|accessdate=26 May 2015|work=New York Times|date=October 7, 2014}}</ref><ref>{{cite news|last1=Randall|first1=Tom|title=Seven Reasons Cheap Oil Can't Stop Renewables Now|url=https://www.bloomberg.com/news/articles/2015-01-30/seven-reasons-cheap-oil-can-t-stop-renewables-now|accessdate=26 May 2015|work=BloombergBusiness|agency=Bloomberg L.P.|date=January 30, 2015}}</ref>
====Natural gas====
Natural gas, which is mostly [[methane]], is viewed as a bridge fuel since it produces about [[emission intensity|half as much]] {{CO2}} as burning coal.<ref name="IPCC Annex II">Moomaw, W., P. Burgherr, G. Heath, M. Lenzen, J. Nyboer, A. Verbruggen, [http://srren.ipcc-wg3.de/report/IPCC_SRREN_Annex_II.pdf 2011: Annex II: Methodology. In IPCC: Special Report on Renewable Energy Sources and Climate Change Mitigation (ref. page 10)]</ref> Gas-fired power plants can provide the required flexibility in electricity production in combination wind and solar energy.<ref>{{cite web |last1=Bertsch |first1=Joachim |last2=Growitsch |first2=Christian |last3=Lorenczik |first3=Stefan |last4=Nagl |first4=Stephan |title=Flexibility options in European electricity markets in high RES-E scenarios |url=https://www.ewi.uni-koeln.de/cms/wp-content/uploads/2015/12/Flexibility_options_in_the_European_electricity_markets.pdf |publisher=University of Cologne |year=2012|accessdate=29 March 2020}}</ref>
But methane is itself a potent greenhouse gas, and it currently leaks from production wells, storage tanks, pipelines, and urban distribution pipes for natural gas.<ref>{{cite press release|url=http://news.mit.edu/2019/role-natural-gas-transition-electricity-1216|title=The uncertain role of natural gas in the transition to clean energy|publisher=MIT News Office|year=2019}}</ref> In a low-carbon scenario, gas-fueled power plants could still continue operation if methane was produced using [[power-to-gas]] technology with renewable energy sources.
===Energy storage===
{{Main|Energy storage}}
{{See also|Hydrogen economy}}
Wind energy and photovoltaics can deliver large amounts of electric energy but not at any time and place. One approach is the conversation into storable forms of energy. This generally leads to losses in efficiency. A study by [[Imperial College London]] calculated the lowest levelised cost of different systems for mid-term and seasonal storage. In 2020, [[Pumped-storage hydroelectricity|pumped hydro]] (PHES), [[Compressed-air energy storage|compressed air]] (CAES) and [[Lithium-ion battery|Li-on batteries]] are most cost effective depending on charging rhythm. For 2040, a more significant role for Li-on and hydrogen is projected.<ref>{{harvnb|Schmidt|Melchior|Hawkes|Staffell|2019}}</ref>
*[[Lithium-ion battery|Li-on batteries]] are widely used in [[battery storage power station]]s and, {{as of|2020|lc=y}}, are starting to be used in [[vehicle-to-grid]] storage.<ref>{{Cite news|url=https://www.reuters.com/article/us-volkswagen-electric-energy-idUSKBN20Z2D5|title=Volkswagen plans to tap electric car batteries to compete with power firms|date=2020-03-12|work=Reuters|access-date=2020-04-07|language=en}}</ref> They provide a sufficient round-trip efficiency of 75-90 %.<ref name="Pellow">{{harvnb|Pellow et al.|2015}}</ref> However their production can cause environmental problems.<ref>{{cite web|url=https://www.wired.co.uk/article/lithium-batteries-environment-impact|title=The spiralling environmental cost of our lithium battery addiction|publisher=WIRED|accessdate=26 January 2020}}</ref>
* [[Hydrogen]] may be useful for [[seasonal energy storage]].<ref>{{Cite web|url=https://oilprice.com/Alternative-Energy/Fuel-Cells/Is-Green-Hydrogen-The-Future-Of-Energy-Storage.html|title=Is Green Hydrogen The Future Of Energy Storage?|website=OilPrice.com|language=en|access-date=2020-04-07}}</ref> The low efficiency of 30% must improve dramatically before hydrogen storage can offer the same overall energy efficiency as batteries.<ref name="Pellow"/> For the electricity grid a German study estimated high costs of 0.176 €/KWh for reconversion concluding that substituting the electricity grid expansion entirely with hydrogen reconversion systems does not make sense from an economic standpoint.<ref>{{harvnb|Welder et al.|2019}}</ref> The concept of solar hydrogen is discussed for remote desert projects where grid connections to demand centers are not available.<ref>{{cite web|url=https://www.solarpowereurope.org/blog-solar-and-hydrogen/|title=Solar + Hydrogen: The perfect match for a Paris-compatible hydrogen strategy?|last1=Beauvais|first1=Aurélie|publisher=Solar Power Europe|date=13 November 2019}}</ref> Because it has more energy per unit volume sometimes it may be better to use hydrogen in [[ammonia]].<ref>{{Cite news|url=https://www.ft.com/content/2014e53c-531f-11ea-a1ef-da1721a0541e|title=Ammonia flagged as green shipping fuel of the future|date=30 March 2020|publisher=[[Financial Times]]}}</ref>
===Super grids===
{{Main|Super grid}}
Long distance power lines help to minimize storage requirements. A large network can smoothen variations of wind energy. With a global grid, even photovoltaics could be available all day and night. The strongest [[High-voltage direct current]] (HVDC) connections are quoted with losses of only 1.6% per 1000 km<ref>{{cite web|title=UHV Grid|url=https://en.geidco.org/aboutgei/uhv/|publisher=Global Energy Interconnection (GEIDCO)|accessdate=26 January 2020}}</ref> HVDC is currently only used for point-to-point connections.
China has built many HVDC connections within the country and supports the idea of a global, intercontinental grid as a backbone system for the existing national [[alternating current|AC]] grids. <ref>{{cite web|title=GEIDCO development strategy|url=https://en.geidco.org/aboutgei/strategy/|publisher=Global Energy Interconnection (GEIDCO)|accessdate=26 January 2020}}</ref> A super grid in the USA in combination with renewable energy could reduce GHG emissions by 80%. <ref>{{cite web|title=North American Supergrid|url=http://climate.org/wp-content/uploads/2019/09/supergrid_9_2019.pdf|publisher=Climate Institute (USA)|accessdate=26 January 2020}}</ref>
===Smart grid and load management===
{{Main|Smart grid|Load management}}
Instead of expanding grids and storage for more power, there are a variety of ways to affect the size and timing of electricity demand on the consumer side. Identifying and shifting electrical loads can reduce power bills by taking advantage of lower off-peak rates and flatten demand peaks. Traditionally, the energy system has treated consumer demand as fixed and used centralised supply options to manage variable demand. Now, better data systems and emerging onsite storageand generation technologies can combine with advanced, automated demand control software to pro-actively manage demand and respond to energy market prices.<ref>{{cite web|title=Renewable Energy and Load Management|url=https://arena.gov.au/assets/2018/10/REALM-Industry-Report_public_FINAL.pdf|publisher=UTS University of Technology Sydney|accessdate=28 March 2020}}</ref>
[[Net energy metering#Time of use metering|Time of use]] metering is a common way to motivate electricity users to reduce their peak load consumption. For instance, running dishwashers and laundry at night after the peak has passed, reduces electricity costs.
[[Dynamic demand]] plans have devices passively shut off when stress is sensed on the electrical grid. This method may work very well with thermostats, when power on the grid sags a small amount, a low power temperature setting is automatically selected reducing the load on the grid. For instance millions of refrigerators reduce their consumption when clouds pass over solar installations. Consumers need to have a [[smart meter]] in order for the utility to calculate credits.
[[Demand response]] devices can receive all sorts of messages from the grid. The message could be a request to use a low power mode similar to dynamic demand, to shut off entirely during a sudden failure on the grid, or notifications about the current and expected prices for power. This allows electric cars to recharge at the least expensive rates independent of the time of day. [[Vehicle-to-grid]] uses a car's battery or fuel cell to supply the grid temporarily.
===Decarbonization of transport===
[[File:Societe de transport de Montreal bus 36-902 - 08.jpg|thumb|[[Electric bus]] in [[Montreal]]]]
{{Main|Electrification|Electric vehicle}}Between a quarter and three-quarters of cars on the road by 2050 are forecast to be electric.<ref>{{Cite web|url=https://www.bhp.com/media-and-insights/prospects/2019/05/the-electrification-of-transport-episode-one|title=The electrification of transport: episode one|website=BHP|language=en|access-date=2020-04-07}}</ref>
[[Hydrogen]] can be a solution for long-distance transport by trucks and [[hydrogen-powered ship]]s where batteries alone are too heavy.<ref>{{Cite news|url=https://www.wired.com/story/want-electric-ships-build-a-better-battery/|title=Want Electric Ships? Build a Better Battery|work=Wired|access-date=2020-04-07|language=en|issn=1059-1028}}</ref><ref>{{Cite web|url=https://www.globalmaritimeforum.org/news/the-scale-of-investment-needed-to-decarbonize-international-shipping|title=The scale of investment needed to decarbonize international shipping|website=www.globalmaritimeforum.org|access-date=2020-04-07}}</ref> Passenger cars using hydrogen are already produced in small numbers. While being more expensive than battery powered cars, they can refuel much faster, offering higher ranges up to 700 km.<ref>{{cite web|url=https://h2.live/en|publisher=H2 mobility|title=Filling up with H2|accessdate=5 April 2020}}</ref> The main disadvantage of hydrogen is the low efficiency of only 30%. When used for vehicles, more than twice as much energy is needed compared to a battery powered electric car. <ref name="vw hydrogen">{{harvnb|Volkswagen AG: Hydrogen or battery|2019}}</ref>
Although [[aviation biofuel]] is used somewhat, {{as of|2019||lc=y}} decarbonisation of aviation by 2050 is claimed to be "really difficult".<ref>{{Cite web|url=https://www.eurocontrol.int/publication/aviation-network-decarbonisation-issues|title=The aviation network - Decarbonisation issues|website=www.eurocontrol.int|language=en|access-date=2020-04-07}}</ref>
===Decarbonization of heating===
{{See also|Electric heating}}
The buildings sector accounts for 23% of global energy-related CO2 emissions<ref>{{harvnb|IPCC SR15 Ch2|2018|p=141}}</ref> About half of the energy is used for space and water heating.<ref>{{harvnb|IEA ETP Buildings|2017}}</ref> A combination of electric heat pumps and building insolation can reduce the primary energy demand significantly. Generally, electrification of heating would only reduce GHG emissions if the electric power comes from low-carbon sources. A fossil-fuel power station may only deliver 3 units of electrical energy for every 10 units of fuel energy released. Electrifying heating loads may also provide a flexible resource that can participate in [[demand response]] to integrate variable renewable resources into the grid.
====Heat pump====
{{Main|Heat pump}}
[[File:Outunit of heat pump.jpg|thumb|upright|Outside unit of an air-source heat pump]]
A modern heat pump typically produces around three times more thermal energy than electrical energy consumed, giving an effective efficiency of 300%, depending on the [[coefficient of performance]]. It uses an electrically driven compressor to operate a [[heat pump and refrigeration cycle|refrigeration cycle]] that extracts heat energy from outdoor air and moves that heat to the space to be warmed. In the summer months, the cycle can be reversed for [[air conditioner|air conditioning]].
In areas with average winter temperatures well below freezing, ground source heat pumps are more efficient than air-source heat pumps. The high purchase price of a heat pump compared to resistance heaters may be offset when air conditioning is also needed.
With a market share of 30% and clean electricity, heat pumps could reduce global {{CO2}} emissions by 8% annually.<ref>{{cite journal |author= Staffell Iain|display-authors=et al |year= 2012 |title= A review of domestic heat pumps |url= |journal= [[Energy and Environmental Science]] |volume= 5 |issue= 11 |pages= 9291–9306 |doi= 10.1039/c2ee22653g}}</ref> Using ground source heat pumps could reduce around 60% of the [[primary energy]] demand and 90% of {{CO2}} emissions of natural gas boilers in Europe in 2050 and make handling high shares of renewable energy easier.<ref>{{cite journal |last1= Carvalho |display-authors=et al |year= 2015 |title= Ground source heat pump carbon emissions and primary energy reduction potential for heating in buildings in Europe—results of a case study in Portugal |url= |journal= [[Renewable and Sustainable Energy Reviews]] |volume= 45 |issue= |pages= 755–768 |doi= 10.1016/j.rser.2015.02.034}}</ref> Using surplus renewable energy in heat pumps is regarded as the most effective household means to reduce global warming and fossil fuel depletion.<ref>{{cite journal |author= Sternberg André, Bardow André |year= 2015 |title= Power-to-What? – Environmental assessment of energy storage systems |url= |journal= [[Energy and Environmental Science]] |volume= 8 |issue= 2 |pages= 389–400 |doi= 10.1039/c4ee03051f}}</ref>
====Electric resistant heating====
[[radiant heating|Radiant heaters]] in households are cheap and wide-spread but less efficient than heat pumps. In areas like Norway, [[Brazil]], and [[Quebec]] that have abundant hydroelectricity, electric heat and hot water are common. Large scale hot water tanks can be used for demand-side management and store variable renewable energy over hours or days.
==Energy conservation==
Reducing energy use is seen as a key solution to the problem of reducing greenhouse gas emissions. According to the [[International Energy Agency]], improved energy efficiency in [[energy-efficient buildings|buildings]], industrial processes and [[sustainable transportation|transportation]] could reduce the world's energy needs in 2050 by one third, and help control global emissions of greenhouse gases.<ref>{{cite web|author=Sophie Hebden |url=http://www.scidev.net/News/index.cfm?fuseaction=readNews&itemid=2929&language=1 |title=Invest in clean technology says IEA report |publisher=Scidev.net |date=2006-06-22 |accessdate=2010-07-16}}</ref>
===Energy efficiency===
{{Main|Efficient energy use|Energy conservation}}
Efficiency covers a wide range of means from [[building insulation]] to [[public transport]]. The [[cogeneration]] of electric energy and [[district heat]] also improves efficiency.
===Lifestyle and behavior===
The [[IPCC]] [[IPCC Fifth Assessment Report|Fifth Assessment Report]] emphasises that behaviour, lifestyle, and cultural change have a high mitigation potential in some sectors, particularly when complementing technological and structural change.<ref name="edenhofer-etal-2014">{{cite book
|first1= Ottmar | last1= Edenhofer
|first2= Ramón | last2= Pichs-Madruga
|display-authors= etal
|editor= IPCC
|year= 2014
|title= Climate change 2014: mitigation of climate change. Contribution of Working Group III to the Fifth Assessment Report of the Intergovernmental Panel on Climate Change
|chapter= Summary for Policymakers
|publisher= [[Cambridge University Press]]
|place= Cambridge, UK and New York, NY, USA
|isbn= 978-1-107-65481-5
|chapter-url= http://www.ipcc.ch/pdf/assessment-report/ar5/wg3/ipcc_wg3_ar5_full.pdf
|access-date= 2016-06-21
}}</ref>{{rp|20}}
Examples would be heating a room less or driving less. In general, higher consumption lifestyles have a greater environmental impact. Several scientific studies have shown that when relatively rich people wish to reduce their carbon footprint, there are a few key actions they can take such as living [[car-free movement|car-free]] (2.4 tonnes CO<sub>2</sub>), avoiding one round-trip transatlantic flight (1.6 tonnes) and eating a [[plant-based diet]] (0.8 tonnes).<ref name=Wynes-Nicholas-2017>{{cite journal |title= The climate mitigation gap: education and government recommendations miss the most effective individual actions |journal= Environmental Research Letters |first1= Seth |last1= Wynes |first2= Kimberly A |last2= Nicholas |date= 12 July 2017 |volume= 12 |page= 074024 |number= 7 |doi= 10.1088/1748-9326/aa7541 |bibcode= 2017ERL....12g4024W|doi-access= free }}</ref>
These appear to differ significantly from the popular advice for "greening" one's lifestyle, which seem to fall mostly into the "low-impact" category: Replacing a typical car with a hybrid (0.52 tonnes); Washing clothes in cold water (0.25 tonnes); Recycling (0.21 tonnes); Upgrading light bulbs (0.10 tonnes); etc. The researchers found that public discourse on reducing one's carbon footprint overwhelmingly focuses on low-impact behaviors, and that mention of the high-impact behaviors is almost non-existent in the mainstream media, government publications, school textbooks, etc.<ref name=Wynes-Nicholas-2017/><ref name=Ceballos-Ehrlich-2017-05>{{cite journal |last1=Ceballos|first1=Gerardo|last2=Ehrlich|first2=Paul P |last3=Dirzo|first3=Rodolfo|date=23 May 2017|title=Biological annihilation via the ongoing sixth mass extinction signaled by vertebrate population losses and declines|journal=[[Proceedings of the National Academy of Sciences of the United States of America]]|volume=114|issue=30|pages=E6089–E6096|quote=Much less frequently mentioned are, however, the ultimate drivers of those immediate causes of biotic destruction, namely, human overpopulation and continued population growth, and overconsumption, especially by the rich. These drivers, all of which trace to the fiction that perpetual growth can occur on a finite planet, are themselves increasing rapidly.|doi=10.1073/pnas.1704949114|pmid=28696295|pmc=5544311}}</ref><ref name="PimmJenkins">{{cite journal |last1=Pimm |first1=S. L. |last2=Jenkins |first2=C. N. |last3=Abell |first3=R. |last4=Brooks|first4=T. M. |last5= Gittleman|first5=J. L. |last6= Joppa |first6=L. N. |last7=Raven|first7=P. H. |last8=Roberts |first8=C. M.|last9= Sexton |first9=J. O.|date=30 May 2014 |title=The biodiversity of species and their rates of extinction, distribution, and protection |url=http://static.squarespace.com/static/51b078a6e4b0e8d244dd9620/t/538797c3e4b07a163543ea0f/1401395139381/Pimm+et+al.+2014.pdf|journal= [[Science (journal)|Science]] |volume= 344|issue=6187|page= 1246752|doi=10.1126/science.1246752 |access-date= 15 December 2016|quote=The overarching driver of species extinction is human population growth and increasing per capita consumption. |pmid=24876501}}</ref>
Scientists also argue that piecemeal behavioural changes like re-using plastic bags are not a proportionate response to climate change. Though being beneficial, these debates would drive public focus away from the requirement for an energy system change of unprecedented scale to decarbonise rapidly.<ref>{{cite news |last1=Corner |first1=Adam |title='Every little helps' is a dangerous mantra for climate change |url=https://www.theguardian.com/sustainable-business/plastic-bags-climate-change-every-little-helps |accessdate=31 March 2020 |work=The Guardian |date=13 December 2013}}</ref>
====Dietary change====
{{See also|Low-carbon diet}}
Overall, food accounts for the largest share of consumption-based GHG emissions with nearly 20% of the global carbon footprint, followed by housing, mobility, services, manufactured products, and construction. Food and services are more significant in poor countries, while mobility and manufactured goods are more significant in rich countries.<ref name="fleurbaey-etal-2014">{{cite book
|first1= Marc | last1= Fleurbaey
|first2= Sivan | last2= Kartha
|display-authors= etal
|editor= IPCC
|year= 2014
|title= Climate change 2014: mitigation of climate change. Contribution of Working Group III to the Fifth Assessment Report of the Intergovernmental Panel on Climate Change
|chapter= Chapter 4: Sustainable Development and Equity
|publisher= [[Cambridge University Press]]
|place= Cambridge, UK and New York, NY, USA
|isbn= 978-1-107-65481-5
|chapter-url= http://www.ipcc.ch/pdf/assessment-report/ar5/wg3/ipcc_wg3_ar5_full.pdf
|access-date= 2016-06-21
}}</ref>{{rp|327}}
The widespread adoption of a vegetarian diet could cut food-related greenhouse gas emissions by 63% by 2050.<ref name="harvey-2016">{{cite news
|last1= Harvey | first1= Fiona
|title= Eat less meat to avoid dangerous global warming, scientists say
|url= https://www.theguardian.com/environment/2016/mar/21/eat-less-meat-vegetarianism-dangerous-global-warming
|access-date= 2016-06-20
|work= The Guardian
|date= 21 March 2016
}}</ref>
China introduced new dietary guidelines in 2016 which aim to cut meat consumption by 50% and thereby reduce greenhouse gas emissions by 1{{nbsp}}billion tonnes by 2030.<ref name="milman-2016">{{cite news
|last1= Milman | first1= Oliver
|title= China's plan to cut meat consumption by 50% cheered by climate campaigners
|url= https://www.theguardian.com/world/2016/jun/20/chinas-meat-consumption-climate-change
|access-date= 2016-06-20
|work= The Guardian
|date= 20 June 2016
}}</ref> A 2016 study concluded that taxes on meat and milk could simultaneously result in reduced greenhouse gas emissions and healthier diets. The study analyzed surcharges of 40% on beef and 20% on milk and suggests that an optimum plan would reduce emissions by 1{{nbsp}}billion tonnes per year.<ref name="carrington-2016">{{cite news
|last= Carrington | first= Damian
|title= Tax meat and dairy to cut emissions and save lives, study urges
|date= 7 November 2016
|work= The Guardian
|location= London, United Kingdom
|issn= 0261-3077
|url= https://www.theguardian.com/environment/2016/nov/07/tax-meat-and-dairy-to-cut-emissions-and-save-lives-study-urges
|access-date= 2016-11-07
}}</ref><ref name="springmann-etal-2016">{{cite journal
|last1= Springmann | first1= Marco
|last2= Mason-D'Croz | first2= Daniel
|last3= Robinson | first3= Sherman
|last4= Wiebe | first4= Keith
|last5= Godfray | first5= H Charles J
|last6= Rayner | first6= Mike
|last7= Scarborough | first7= Peter
| s2cid= 88921469
|title= Mitigation potential and global health impacts from emissions pricing of food commodities
|date= 7 November 2016
|journal= Nature Climate Change
|volume =7
| issue= 1
|page =69
|doi= 10.1038/nclimate3155
|issn= 1758-678X
|bibcode= 2017NatCC...7...69S}}</ref>
==Carbon sinks and removal==
{{Main|Carbon sink|Carbon dioxide removal}}
A [[carbon sink]] is a natural or artificial reservoir that accumulates and stores some carbon-containing chemical compound for an indefinite period, such as a growing [[forest]]. [[Carbon dioxide removal]] on the other hand is a permanent removal of carbon dioxide out of the atmosphere. Examples are [[carbon capture and storage|direct air capture]], [[enhanced weathering]] technologies such as storing it in [[geologic sequestration of CO2|geologic formations]] underground and [[biochar]]. These processes are sometimes considered variations of sinks or mitigation,<ref>{{cite web
|title=OECD Environmental Outlook to 2050, Climate Change Chapter, pre-release version
|url=http://www.oecd.org/dataoecd/32/53/49082173.pdf
|publisher=[[OECD]]
|year=2011
|accessdate=2012-04-23
}}</ref><ref name="IEA Technology Roadmap Carbon Capture and Storage 2009">
{{cite web
|title=IEA Technology Roadmap Carbon Capture and Storage 2009
|url=https://www.iea.org/papers/2009/CCS_Roadmap.pdf
|publisher=[[OECD]]/IEA
|year=2009
|accessdate=2012-04-23
|archive-url=https://web.archive.org/web/20101204203455/http://www.iea.org/papers/2009/CCS_Roadmap.pdf
|archive-date=2010-12-04
|url-status=dead
}}
</ref> and sometimes as geoengineering.<ref>{{cite web
|title=Geoengineering the climate: science, governance and uncertainty
|url=http://royalsociety.org/policy/publications/2009/geoengineering-climate/
|publisher=[[The Royal Society]]
|year=2009
|accessdate=2012-04-23
}}</ref> In combination with other mitigation measures, carbon sinks and removal are crucial for meeting the 2 degree target.<ref>{{Cite web|url=http://www.sintef.no/en/latest-news/this-is-what-you-need-to-know-about-ccs-carbon-capture-and-storage/|title=This is what you need to know about CCS – Carbon Capture and Storage|website=SINTEF|language=en|access-date=2020-04-02}}</ref>
The Antarctic Climate and Ecosystems Cooperative Research Centre (ACE-CRC) notes that one third of humankind's annual emissions of {{CO2}} are absorbed by the oceans.<ref>{{cite web|url=http://www.acecrc.org.au/Research/Southern%20Ocean%20Carbon%20Sink |title=Archived copy |accessdate=July 21, 2013 |url-status=dead |archiveurl=https://web.archive.org/web/20130811112807/http://www.acecrc.org.au/Research/Southern%20Ocean%20Carbon%20Sink |archivedate=August 11, 2013}}</ref> However, this also leads to [[ocean acidification]], which may harm marine life.<ref>{{cite web|url=http://www.csiro.au/Outcomes/Climate/Understanding/ClimateChangeCO2inOceans.aspx |title=Archived copy |accessdate=July 21, 2013 |url-status=dead |archiveurl=https://web.archive.org/web/20130514141655/http://www.csiro.au/Outcomes/Climate/Understanding/ClimateChangeCO2inOceans.aspx |archivedate=May 14, 2013}}</ref> Acidification lowers the level of carbonate ions available for calcifying organisms to form their shells. These organisms include plankton species that contribute to the foundation of the [[Southern Ocean]] food web. However acidification may impact on a broad range of other physiological and ecological processes, such as [[Ocean deoxygenation|fish respiration]], larval development and changes in the solubility of both nutrients and toxins.<ref>{{cite web|url=http://www.acecrc.org.au/Research/Ocean%20Acidification |title=Archived copy |accessdate=July 21, 2013 |url-status=dead |archiveurl=https://web.archive.org/web/20130811132348/http://www.acecrc.org.au/Research/Ocean%20Acidification |archivedate=August 11, 2013}}</ref>
===Reforestation, avoided deforestation and afforestation===
[[File:Shennongjia virgin forest.jpg|thumb|Transferring [[land rights]] to indigenous inhabitants is argued to efficiently conserve forests.]]
{{Main|Deforestation|Reforestation|Biosequestration}}
{{See|Carbon_sequestration#Forestry}}
According to research by Tom Crowther et al., there is still enough room to plant an additional 1.2 trillion trees. This amount of trees would cancel out the last 10 years of CO<sub>2</sub> emissions and sequester 160 billion tons of carbon.<ref>{{Cite journal|last=Ehrenberg|first=Rachel|title=Global count reaches 3 trillion trees|url=http://www.nature.com/news/global-count-reaches-3-trillion-trees-1.18287|journal=Nature News|language=en|doi=10.1038/nature.2015.18287}}</ref><ref>{{Cite web|url=https://www.cnn.com/2019/04/17/world/trillion-trees-climate-change-intl-scn/index.html|title=The most effective way to tackle climate change? Plant 1 trillion trees|first=Mark |last=Tutton|website=CNN|access-date=2020-02-13}}</ref><ref>{{Cite web|url=https://www.nextbigfuture.com/2019/06/we-have-room-to-add-35-more-trees-globally-to-store-160-billion-tons-of-co2.html|title=We Have Room to Add 35% More Trees Globally to Store 580-830 Billion Tons of CO2 – NextBigFuture.com|last=Wang|first=Brian|website=www.nextbigfuture.com|language=en-US|access-date=2020-02-13}}</ref><ref>{{Cite web|url=https://www.crowtherlab.com/|title=Home|website=Crowtherlab|language=en-US|access-date=2020-02-13}}</ref>This vision is being executed by the [[Trillion Tree Campaign]]. According to research conducted at ETH Zurich, restoring all degraded forests all over the world could capture about 205 billion tons of carbon in total (which is about 2/3rd of all carbon emissions, bringing global warming down to below 2 °C{{cn|date=November 2019}}).<ref>{{Cite web|url=https://www.cnn.com/2019/07/04/world/forests-capture-two-thirds-of-carbon-emissions-scn-intl/index.html|title=Restoring forests could capture two-thirds of the carbon humans have added to the atmosphere|first=Mark |last=Tutton|website=CNN|access-date=2020-02-13}}</ref><ref>{{Cite journal|last1=Chazdon|first1=Robin|last2=Brancalion|first2=Pedro|date=2019-07-05|title=Restoring forests as a means to many ends|journal=Science|language=en|volume=365|issue=6448|pages=24–25|doi=10.1126/science.aax9539|issn=0036-8075|pmid=31273109|bibcode=2019Sci...365...24C}}</ref> other research has found large-sacle tree planting can do more harm than good.<ref>{{Cite news|last=McGrath|first=Matt|date=2020-06-22|title=Planting new forests 'can do more harm than good'|language=en-GB|work=BBC News|url=https://www.bbc.com/news/science-environment-53138178|access-date=2020-06-23}}</ref>
Almost 20 percent (8{{nbsp}}GtCO<sub>2</sub>/year) of total greenhouse-gas emissions were from deforestation in 2007.{{Update inline|date=February 2020|reason=}} It is estimated that avoided deforestation reduces CO<sub>2</sub> emissions at a rate of 1{{nbsp}}tonne of CO<sub>2</sub> per $1–5 in [[opportunity costs]] from lost agriculture. [[Reforestation]] could save at least another 1{{nbsp}}GtCO<sub>2</sub>/year, at an estimated cost of $5–15/tCO<sub>2</sub>.<ref name="stern">Stern, N. (2006). ''Stern Review on the Economics of Climate Change: Part III: The Economics of Stabilisation.'' HM Treasury, London: http://hm-treasury.gov.uk/sternreview_index.htm</ref> [[Afforestation]] is where there was previously no forest – such plantations are estimated to have to be prohibitively massive to reduce emissions by itself{{Clarify|reason=reduce emissions by itself? what does that mean here?|date=April 2020}}.<ref>Lena R. Boysen, Wolfgang Lucht, Dieter Gerten, Vera Heck, Timothy M. Lenton, Hans Joachim Schellnhuber. The limits to global-warming mitigation by terrestrial carbon removal. ''Earth's Future'', 2017; https://www.sciencedaily.com/releases/2017/05/170518104038.htm DOI: 10.1002/2016EF000469</ref>
Transferring rights over land from public domain to its indigenous inhabitants, who have had a stake for millennia in preserving the forests that they depend on, is argued to be a cost-effective strategy to conserve forests.<ref name=Guardian1>{{cite news|url= https://www.theguardian.com/global-development/2016/jul/22/india-follow-china-saving-forest-people-land-rights|title=India should follow China to find a way out of the woods on saving forest people|newspaper=The Guardian |access-date=2 November 2016|date=22 July 2016}}</ref> This includes the protection of such rights entitled in existing laws, such as India's [[The Scheduled Tribes and Other Traditional Forest Dwellers (Recognition of Forest Rights) Act, 2006|Forest Rights Act]].<ref name=Guardian1/> The transferring of such rights in [[China]], perhaps the largest [[land reform]] in modern times, has been argued to have increased forest cover.<ref name=fp0718/><ref name=rightsandresources>{{cite web|url=http://rightsandresources.org/en/publication/view/chinas-forest-tenure-reforms-impacts-and-implications-for-choice-conservation-and-climate-change/|title=China's forest tenure reforms|publisher=rightsandresources.org |accessdate=7 August 2016}}</ref> Granting title of the land has shown to have two or three times less clearing than even state run parks, notably in the Brazilian Amazon.<ref name="ding-etal-2016-webpage">{{cite web
|first1= Helen | last1= Ding
|first2= Peter | last2= Veit
|first3= Erin | last3= Gray
|first4= Katie | last4= Reytar
|first5= Juan-Carlos | last5= Altamirano
|first6= Allen | last6= Blackman
|first7= Benjamin | last7= Hodgdon
|date= October 2016
|title= Climate benefits, tenure costs: The economic case for securing indigenous land rights in the Amazon
|website= World Resources Institute (WRI)
|location= Washington DC, USA
|url= http://www.wri.org/publication/climate-benefits-tenure-costs
|access-date= 2016-11-02
}}</ref><ref name="ding-etal-2016">{{cite book
|first1= Helen | last1= Ding
|first2= Peter G | last2= Veit
|first3= Allen | last3= Blackman
|first4= Erin | last4= Gray
|first5= Katie | last5= Reytar
|first6= Juan-Carlos | last6= Altamirano
|first7= Benjamin | last7= Hodgdon
|date= 2016
|title= Climate benefits, tenure costs: The economic case for securing indigenous land rights in the Amazon
|publisher= World Resources Institute (WRI)
|location= Washington DC, USA
|isbn= 978-1-56973-894-8
|url= http://www.wri.org/sites/default/files/Climate_Benefits_Tenure_Costs.pdf
|access-date= 2016-11-02
}}</ref> Excluding humans and even evicting inhabitants from protected areas (called "fortress conservation") often lead to more exploitation of the land as the native inhabitants then turn to work for extractive companies to survive.<ref name=fp0718>{{cite magazine|url= https://foreignpolicy.com/2018/07/16/how-conservation-became-colonialism-environment-indigenous-people-ecuador-mining/|title=How Conservation Became Colonialism|magazine=Foreign Policy |access-date=30 July 2018|date=16 July 2018}}</ref>
With increased [[intensive agriculture]] and [[urbanization]], there is an increase in the amount of abandoned farmland. By some estimates, for every half a hectare of original [[old-growth forest]] cut down, more than 20 hectares of new [[secondary forest]]s are growing,{{cn|date=November 2019}} even though they do not have the same biodiversity as the original forests and original forests store 60% more carbon than these new secondary forests.<ref>{{cite news|url= https://www.nytimes.com/2009/01/30/science/earth/30forest.html?pagewanted=all|title=New Jungles Prompt a Debate on Rain Forests|newspaper=New York Times |accessdate=18 July 2016|date=29 January 2009}}</ref><ref>Young, E. (2008). ''IPCC Wrong On Logging Threat to Climate.'' New Scientist, August 5, 2008. Retrieved on August 18, 2008, from https://www.newscientist.com/article/dn14466-ipcc-wrong-on-logging-threat-toclimate.html</ref> According to a study in ''[[Science (journal)|Science]]'', promoting regrowth on abandoned farmland could offset years of carbon emissions.<ref>{{cite news|url= https://www.nytimes.com/2016/05/17/science/forests-carbon-dioxide.html?_r=1|title=In Latin America, Forests May Rise to Challenge of Carbon Dioxide|newspaper=New York Times |accessdate=18 July 2016|date=16 May 2016}}</ref> Research by the university ETH Zurich estimates that Russia, the United States and Canada have the most land suitable for reforestation.<ref>{{Cite news|url=https://www.nytimes.com/2019/07/05/climate/trees-forests-climate-change.html|title=Restoring Forests Could Help Put a Brake on Global Warming, Study Finds|last=Sengupta|first=Somini|date=2019-07-05|work=The New York Times|access-date=2019-07-07|language=en-US|issn=0362-4331}}</ref><ref>[https://cdn.website-editor.net/7b672694d0e642a28c4eb078a071e391/files/uploaded/The%2520Global%2520Tree%2520Restoration%2520Potential.pdf RESTORATION ECOLOGY:The global tree restoration potential] cdn.website-editor.net, 5 July 2019. Retrieved 9 August 2019.</ref>
===Avoided desertification===
Restoring grasslands stores CO<sub>2</sub> from the air in plant material. Grazing livestock, usually not left to wander, would eat the grass and would minimize any grass growth. However, grass left alone would eventually grow to cover its own growing buds, preventing them from photosynthesizing and the dying plant would stay in place.<ref name=Tlovell>{{cite news|url=http://www.newstatesman.com/environment/2011/01/lovell-carbon-ward-climate|title=How fences could save the planet|publisher=newstatesman.com|accessdate=May 5, 2013|date=January 13, 2011}}</ref> A method proposed to restore grasslands uses fences with many small paddocks and moving herds from one paddock to another after a day or two in order to mimic natural grazers and allowing the grass to grow optimally.<ref name=Tlovell/><ref>{{cite news|url=http://news.mongabay.com/2008/0221-soil_carbon_lovell_interview.html|title=Restoring soil carbon can reverse global warming, desertification and biodiversity|publisher=mongabay.com|accessdate=May 5, 2013|date=February 21, 2008|url-status=dead|archiveurl=https://archive.is/20130625040133/http://news.mongabay.com/2008/0221-soil_carbon_lovell_interview.html|archivedate=June 25, 2013}}</ref><ref>{{cite news|url=http://www.time.com/time/magazine/article/0,9171,1953692,00.html|title=How eating grass-fed beef could help fight climate change|publisher=time.com|accessdate=May 11, 2013|date=January 25, 2010}}</ref> Additionally, when part of the leaf matter is consumed by an animal in the herd, a corresponding amount of root matter is sloughed off too as it would not be able to sustain the previous amount of root matter and while most of the lost root matter would rot and enter the atmosphere, part of the carbon is sequestered into the soil.<ref name=Tlovell/> It is estimated that increasing the carbon content of the soils in the world's 3.5 billion hectares of agricultural grassland by 1% would offset nearly 12 years of CO<sub>2</sub> emissions.<ref name=Tlovell/> [[Allan Savory]], as part of [[holistic management]], claims that while large herds are often blamed for [[desertification]], prehistoric lands supported large or larger herds and areas where herds were removed in the United States are still desertifying.<ref name=ASavory>{{cite news|url=http://newswatch.nationalgeographic.com/2013/03/06/how-cows-could-repair-the-world-allan-savory-at-ted/|title=How cows could repair the world|publisher=nationalgeographic.com|accessdate=May 5, 2013|date=March 6, 2013}}</ref>
Additionally, the global warming induced thawing of the [[permafrost#Climate change effects|permafrost]], which stores about two times the amount of the carbon currently released in the atmosphere,<ref>{{Cite journal|title=The Global Carbon Cycle: A Test of Our Knowledge of Earth as a System|journal=Science|volume=290|issue=5490|pages=291–6|author=P. Falkowski|date=13 October 2000|pmid=11030643|display-authors=etal|doi=10.1126/science.290.5490.291|bibcode=2000Sci...290..291F}}</ref> releases the potent greenhouse gas, [[Atmospheric methane|methane]], in a [[positive feedback|positive feedback cycle]] that is feared to lead to a [[tipping point (climatology)|tipping point]] called [[runaway climate change]]. A method proposed to prevent such a scenario is to bring back large herbivores such as seen in [[Pleistocene Park]], where their trampling naturally keep the ground cooler by eliminating shrubs and keeping the ground exposed to the cold air.<ref>{{cite journal|title=Methane bubbling from Siberian thaw lakes as a positive feedback to climate warming|author1=K. M. Walter |author2=S. A. Zimov |author3=J. P. Chanton |author4=D. Verbyla |author5-link=F. Stuart Chapin III |author5=F.S. Chapin III|date=7 September 2006|journal=[[Nature (journal)|Nature]] |volume=443|issue=7107|pages=71–5|doi=10.1038/nature05040|pmid=16957728|bibcode=2006Natur.443...71W }}</ref>
Protect healthy soils and recover damaged soils, can remove from the atmosphere 5.5 billion tons of carbon annually, what is approximately equal to the annual emissions of the USA.<ref>{{cite news |last1=Rosane |first1=Olivia |title=Protecting and Restoring Soils Could Remove 5.5 Billion Tonnes of CO2 a Year |url=https://www.ecowatch.com/soil-protection-co2-2645518371.html |accessdate=19 March 2020 |agency=Ecowatch |date=18 March 2020}}</ref>
===Carbon capture and storage===
[[File:Carbon sequestration-2009-10-07.svg|thumb|upright=1.35|Schematic showing both terrestrial and geological sequestration of carbon dioxide emissions from a large point source, for example burning natural gas]]
{{Main|Carbon capture and storage}}{{See also|CCS and climate change mitigation}}
Carbon capture and storage (CCS) is a method to mitigate climate change by capturing [[carbon dioxide]] (CO<sub>2</sub>) from large point sources such as power plants and subsequently storing it away safely instead of releasing it into the atmosphere. The IPCC estimates that the costs of halting global warming would double without CCS.<ref name=guardian0916>{{cite news|url=https://www.theguardian.com/environment/2016/jun/09/co2-turned-into-stone-in-iceland-in-climate-change-breakthrough|title=CO2 turned into stone in Iceland in climate change breakthrough|newspaper=The Guardian|accessdate=2 September 2017|date=9 June 2016}}</ref> The International Energy Agency says CCS is "the most important single new technology for CO<sub>2</sub> savings" in power generation and industry.<ref name=futureenergysummit>{{cite magazine|last=Robinson |first=Simon |url=http://www.time.com/time/specials/packages/article/0,28804,1954176_1954175,00.html |title=How to Reduce Carbon Emissions: Capture and Store it? |magazine=[[Time.com]] |date=2010-01-22 |accessdate=2010-08-26}}</ref>{{Better source|date=February 2020|reason=too old}} Norway's [[Sleipner gas field]], beginning in 1996, stores almost a million tons of CO<sub>2</sub> a year to avoid penalties in producing natural gas with unusually high levels of CO<sub>2</sub>.<ref>{{Cite web|url=https://sequestration.mit.edu/tools/projects/sleipner.html|title=Carbon Capture and Sequestration Technologies @ MIT|website=sequestration.mit.edu|access-date=2020-01-24}}</ref><ref name=futureenergysummit/> According to a [[Sierra Club]] analysis, the US [[Kemper Project]], which was due to be online in 2017, is the most expensive power plant ever built for the watts of electricity it will generate.<ref name="Drajem">{{cite magazine |last= Drajem |first= Mark |title= Coal's Best Hope Rising With Costliest U.S. Power Plant |magazine= Bloomberg Business |date= April 14, 2014 |url= https://www.bloomberg.com/news/articles/2014-04-14/coal-s-best-hope-rising-with-costliest-u-s-power-plant}}</ref>
===Enhanced weathering===
Enhanced weathering is the removal of carbon from the air into the earth, enhancing the natural [[carbon cycle]] where carbon is mineralized into rock. The [[CarbFix]] project couples with carbon capture and storage in power plants to turn carbon dioxide into stone in a relatively short period of two years. While this project used [[basalt]] rocks, [[olivine]] has also shown promise.<ref name=guardian0916/>
==Geoengineering==
{{Main|Climate engineering}}
IPCC (2007) concluded that geoengineering options, such as [[ocean fertilization]] to remove CO<sub>2</sub> from the [[atmosphere]], remained largely unproven.<ref>{{cite book
|year=2007
|title=C. Mitigation in the short and medium term (until 2030). In (book section): Summary for Policymakers. In: Climate Change 2007: Mitigation. Contribution of Working Group III to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change (B. Metz ''et al.'' (eds.))
|publisher=Print version: Cambridge University Press, Cambridge, UK, and New York, NY, US. This version: IPCC website
|isbn=978-0-521-88011-4
|author=IPCC
|url=http://www.ipcc.ch/publications_and_data/ar4/wg3/en/spmsspm-c.html
|accessdate=2010-05-15
|archive-url=https://web.archive.org/web/20100502182529/http://www.ipcc.ch/publications_and_data/ar4/wg3/en/spmsspm-c.html
|archive-date=2010-05-02
|url-status=dead
}}</ref> It was judged that reliable cost estimates for geoengineering had not yet been published.
Chapter 28 of the [[United States National Academy of Sciences|National Academy of Sciences]] report ''Policy Implications of Greenhouse Warming: Mitigation, Adaptation, and the Science Base'' (1992) defined geoengineering as "options that would involve large-scale engineering of our environment in order to combat or counteract the effects of changes in atmospheric chemistry."<ref name="nas_policy_implications">[http://books.nap.edu/openbook.php?record_id=1605&page=433 Policy Implications of Greenhouse Warming: Mitigation, Adaptation, and the Science Base] (1992), [[Committee on Science, Engineering, and Public Policy]] (COSEPUP)</ref> They evaluated a range of options to try to give preliminary answers to two questions: can these options work and could they be carried out with a reasonable cost. They also sought to encourage discussion of a third question — what adverse side effects might there be. Increasing ocean absorption of carbon dioxide (carbon sequestration) and screening out some sunlight were evaluated. NAS also argued "Engineered countermeasures need to be evaluated but should not be implemented without broad understanding of the direct effects and the potential side effects, the ethical issues, and the risks."<ref name="nas_policy_implications"/> In July 2011 a report by the [[United States Government Accountability Office]] on geoengineering found that "[c]limate engineering technologies do not now offer a viable response to global climate change."<ref>GAO (2011). Technical status, future directions, and potential responses. July 2011. [http://gao.gov/products/GAO-11-71 GAO-11-71]</ref>
===Carbon dioxide removal===
{{Main|Carbon dioxide removal|Greenhouse gas remediation|Carbon sequestration}}
{{See also|Carbon air capture}}
[[Carbon dioxide removal]] has been proposed as a method of reducing the amount of radiative forcing. A variety of means of artificially capturing and storing carbon, as well as of enhancing natural sequestration processes, are being explored. The main natural process is [[photosynthesis]] by plants and single-celled organisms (see [[biosequestration]]). Artificial processes vary, and concerns have been expressed about the long-term effects of some of these processes.<ref name=RoyalSociety>The Royal Society, (2009) [http://royalsociety.org/displaypagedoc.asp?id=35151 "Geoengineering the climate: science, governance and uncertainty"]. Retrieved 2009-09-12.</ref>
It is notable that the availability of cheap energy and appropriate sites for [[carbon capture and storage|geological storage]] of carbon may make [[carbon dioxide air capture]] viable commercially. It is, however, generally expected that carbon dioxide air capture may be uneconomic when compared to [[carbon capture and storage]] from major sources — in particular, fossil fuel powered power stations, refineries, etc. As in the case of the US [[Kemper Project]] with carbon capture, costs of energy produced will grow significantly. CO<sub>2</sub> can also be used in commercial [[greenhouse]]s, giving an opportunity to kick-start the technology.
===Solar radiation management===
{{Main|Solar radiation management}}
{{See also|Stratospheric aerosol injection (climate engineering)}}
The main purpose of solar radiation management is to reflect sunlight and thus reduce global warming. The ability of stratospheric [[sulfate aerosols]] to create a [[global dimming]] effect has made them a possible candidate for use in [[climate engineering]] projects.<ref>{{cite journal |url=http://journals.royalsociety.org/content/84j11614488142u8/ |journal=Phil. Trans. R. Soc. A |year=2008 |volume=366 |pages=4039–4056 |title=Global and Arctic climate engineering: numerical model studies |doi=10.1098/rsta.2008.0132 |author1=Launder B. |author2=J.M.T. Thompson |pmid=18757275 |issue=1882 |bibcode=2008RSPTA.366.4039C|doi-access=free }}</ref>
==Agriculture==
{{See also|Climate change and agriculture|Environmental impact of meat production|Sustainable agriculture}}
[[File:Cow female black white.jpg|thumb|Managed grazing methods are argued to be able to restore grasslands, thereby significantly decreasing atmospheric CO<sub>2</sub> levels.<ref name=ASavory/>]]
An agriculture that mitigates climate change is generally called [[sustainable agriculture]], defined as an agriculture that "meets society's food and textile needs in the present without compromising the ability of future generations to meet their own needs".<ref>{{Cite web |url=https://asi.ucdavis.edu/programs/ucsarep/about/what-is-sustainable-agriculture |title=What is sustainable agriculture {{!}} Agricultural Sustainability Institute|website=asi.ucdavis.edu |access-date=2019-01-20}}</ref>
One mode of agriculture considered as relatively sustainable is [[regenerative agriculture]].<ref>{{cite web |last1=Scanlon |first1=Kerry |title=Trends in Sustainability: Regenerative Agriculture |url=https://www.rainforest-alliance.org/business/blog/2018/10/18/trends-in-sustainability-regenerative-agriculture/ |website=Rainforest Alliance |accessdate=29 October 2019}}</ref> It includes several methods, the main of which are: conservation tillage, diversity, rotation and cover crops, minimizing physical disturbance, minimizing the usage of chemicals. It has other benefits like improving the state of the soil and consequently yields. Some of the big agricultural companies like [[General Mills]] and a lot of farms support it.<ref>{{cite news |title=What Is Regenerative Agriculture? |url=https://www.ecowatch.com/regenerative-agriculture-2639054637.html |accessdate=3 July 2019 |agency=The Climate Reality Project |publisher=Ecowatch |date=July 2, 2019}}</ref>
In the United States, soils account for about half of agricultural [[greenhouse gas]] emissions while agriculture, forestry and other land use emits 24%.<ref>{{cite web|url=https://www.epa.gov/ghgemissions/global-greenhouse-gas-emissions-data|title=Agriculture: Sources of Greenhouse Gas Emissions by Sector|year=2019|publisher=EPA}}</ref> Globally, livestock is responsible for 18 percent of greenhouse gas emissions, according to [[FAO]]'s report called "[[Livestock's_Long_Shadow|Livestock's Long Shadow: Environmental Issues and Options]]"<ref>{{cite web|url=ftp://ftp.fao.org/docrep/fao/010/a0701e/a0701e03.pdf|title=Livestock impacts on the environment|year=2006|website=|publisher=[[Food and Agriculture Organization of the United Nations]]|accessdate=October 25, 2016|author=FAO Agriculture and Consumer Protection Department|archiveurl=https://web.archive.org/web/20150828131058/http://www.fao.org/ag/magazine/0612sp1.htm|archivedate=August 28, 2015}}</ref>{{Better source|date=February 2020|reason=too old}}
The US [[EPA]] says [[soil management]] practices that can reduce the emissions of [[nitrous oxide]] ({{chem|N|2|O}}) from soils include [[fertilizer]] usage, [[irrigation]], and [[tillage]]. Manure management and rice cultivation also produce gaseous emissions.
Important mitigation options for reducing the greenhouse gas emissions from livestock (especially [[ruminant]]s) include genetic selection<ref>[https://www.genomecanada.ca/en/programs/large-scale-science/past-competitions/strategic-initiatives/bovine-genomics Bovine genomics project at Genome Canada]</ref><ref>[https://www.wired.com/story/canada-is-using-genetics-to-make-cows-less-gassy/ Canada is using genetics to make cows less gassy]</ref> introduction of [[Methanotroph|methanotrophic bacteria]] into the rumen,<ref>[https://hal.archives-ouvertes.fr/hal-01137190/document The use of direct-fed microbials for mitigation of ruminant methane emissions: a review]</ref><ref>{{cite journal |doi=10.1080/21553769.2015.1063550 |title=Exploring diet-dependent shifts in methanogen and methanotroph diversity in the rumen of Mehsani buffalo by a metagenomics approach |journal=Frontiers in Life Science |volume=8 |issue=4 |pages=371–378 |year=2015 |last1=Parmar |first1=N.R. |last2=Nirmal Kumar |first2=J.I. |last3=Joshi |first3=C.G. }}</ref> diet modification and grazing management.<ref>{{cite journal | last1 = Boadi | first1 = D | year = 2004 | title = Mitigation strategies to reduce enteric methane emissions from dairy cows: Update review | url = | journal = Can. J. Anim. Sci. | volume = 84 | issue = 3| pages = 319–335 | doi = 10.4141/a03-109 | doi-access = free }}</ref><ref>Martin, C. et al. 2010. Methane mitigation in ruminants: from microbe to the farm scale. ''Animal'' 4 : pp 351-365.</ref><ref>{{cite journal | last1 = Eckard | first1 = R. J. | display-authors = etal | year = 2010 | title = Options for the abatement of methane and nitrous oxide from ruminant production: A review | url = | journal = Livestock Science | volume = 130 | issue = 1–3| pages = 47–56 | doi=10.1016/j.livsci.2010.02.010}}</ref> Other options include just using ruminant-free alternatives instead, such as [[milk substitute]]s and [[meat analogue]]s. Non-ruminant livestock (e.g. poultry) generates far fewer emissions.<ref>[https://www.sciencedirect.com/science/journal/03016226/96/1 Livestock Farming Systems and their Environmental Impact]</ref>
Methods that enhance carbon sequestration in soil include [[no-till farming]], residue mulching, [[cover crop]]ping, and [[crop rotation]], all of which are more widely used in [[organic farming]] than in conventional farming.<ref>{{cite web |url=http://www.news.cornell.edu/stories/July05/organic.farm.vs.other.ssl.html |title=Organic farming produces same corn and soybean yields as conventional farms, but consumes less energy and no pesticides, study finds |author=Susan S. Lang |date=13 July 2005 |accessdate=8 July 2008}}</ref><ref>{{cite journal |last1=Pimentel |first1=David |title=Environmental, Energetic, and Economic Comparisons of Organic and Conventional Farming Systems |journal=BioScience |volume=55 |issue=7 |pages=573–82 |year=2005 |doi=10.1641/0006-3568(2005)055[0573:EEAECO]2.0.CO;2 |last2=Hepperly |first2=Paul |last3=Hanson |first3=James |last4=Douds |first4=David |last5=Seidel |first5=Rita|doi-access=free }}</ref> Because only 5% of US farmland currently uses no-till and residue mulching, there is a large potential for carbon sequestration.<ref>{{cite journal |doi=10.1126/science.1093079 |title=Ecology: Managing Soil Carbon |year=2004 |last1=Lal |first1=Rattan |journal=Science |volume=304 |issue=5669 |page=393 |pmid=15087532 |last2=Griffin |first2=Michael |last3=Apt |first3=Jay |last4=Lave |first4=Lester |last5=Morgan |first5=M. Granger|s2cid=129925989 }}</ref>
A 2015 study found that farming can deplete soil carbon and render soil incapable of supporting life; however, the study also showed that [[conservation farming]] can protect carbon in soils, and repair damage over time.<ref>{{cite journal|url=https://eos.org/research-spotlights/conservation-farming-shown-to-protect-carbon-in-soil|title=Conservation Farming Shown to Protect Carbon in Soil|journal=Journal of Geophysical Research: Biogeosciences|author=A. N. (Thanos) Papanicolaou |author2=Kenneth M. Wacha |author3=Benjamin K. Abban |author4=Christopher G. Wilson |author5=Jerry L. Hatfield |author6=Charles O. Stanier |author7=Timothy R. Filley|year=2015|doi=10.1002/2015JG003078|volume=120|issue=11|pages=2375–2401|bibcode=2015JGRG..120.2375P|doi-access=free}}</ref> The farming practice of [[cover crop]]s has been recognized as [[climate-smart agriculture]].<ref>{{cite news|url=https://www.nytimes.com/2016/02/07/business/cover-crops-a-farming-revolution-with-deep-roots-in-the-past.html?_r=0|newspaper=The New York Times|title=Cover Crops, a Farming Revolution With Deep Roots in the Past|year=2016}}</ref> Best management practices for European soils were described to be increase soil organic carbon: conversion of arable land to grassland, straw incorporation, reduced tillage, straw incorporation combined with reduced tillage, ley cropping system and cover crops.<ref>{{cite journal|last1=Lugato|first1=Emanuele|last2=Bampa|first2=Francesca|last3=Panagos|first3=Panos|last4=Montanarella|first4=Luca|last5=Jones|first5=Arwyn|date=2014-11-01|title=Potential carbon sequestration of European arable soils estimated by modelling a comprehensive set of management practices|journal=Global Change Biology|volume=20|issue=11|pages=3557–3567|doi=10.1111/gcb.12551|pmid=24789378|issn=1365-2486|bibcode=2014GCBio..20.3557L}}</ref>
In terms of prevention, vaccines are being developed in Australia to reduce the significant global warming contributions from [[methane]] released by livestock via [[flatulence]] and [[eructation]].<ref>[https://www.newscientist.com/article.ns?id=dn6431 Burp vaccine cuts greenhouse gas emissions] ''Rachel Nowak'' for NewScientist September 2004</ref>{{Update inline|date=February 2020|reason=}}
A project to mitigate climate change with agriculture was launched in 2019 by the "Global EverGreening Alliance". The target is to sequester carbon from the atmosphere with [[Agroforestry]]. By 2050 the restored land should sequestrate 20 billion of carbon annually<ref>{{cite news |last1=Hoffner |first1=Erik |title=Grand African Savannah Green Up': Major $85 Million Project Announced to Scale up Agroforestry in Africa |url=https://www.ecowatch.com/agroforestry-africa-climate-summit-2641102482.html |accessdate=27 October 2019 |agency=Ecowatch |date=October 25, 2019}}</ref>
==Societal responses==
===Sustainable transport concepts===
{{Main|Sustainable transport}}
Transportation emissions account for roughly 1/4 of emissions worldwide<ref name="world energy council">{{cite web |url=http://www.worldenergy.org/publications/809.asp |title=Transport Technologies and Policy Scenarios |publisher=[[World Energy Council]] |access-date=2009-05-26 |author=World Energy Council |year=2007 |url-status=dead |archive-url=https://web.archive.org/web/20081204051628/http://www.worldenergy.org/publications/809.asp |archive-date=2008-12-04 |df= }}</ref>{{Better source|date=February 2020|reason=too old}} and are even more important in terms of impact in developed nations especially in North America and Australia. Many citizens of countries like the United States and Canada who drive personal cars often, see well over half of their climate change impact stemming from the emissions produced from their cars.{{cn|date=October 2019}} Modes of mass transportation such as bus, light rail (metro, subway, etc.), and long-distance rail are far and away the most energy-efficient means of motorized transportation for passengers, able to use in many cases over twenty times less energy per person-distance than a personal automobile. Modern [[efficient energy use|energy-efficient technologies]], such as [[electric vehicle]]s and [[carbon-neutral fuel|carbon-neutral synthetic gasoline and jet fuel]]{{Citation needed|date=February 2020}} may also help to reduce the consumption of [[petroleum]], land use changes and emissions of [[carbon dioxide]]. Utilizing [[rail transport]], especially electric rail, over the far less efficient [[environmental impact of aviation|air transport]] and [[road transport|truck transport]]
significantly reduces emissions.<ref>{{cite web
|author= Lowe, Marcia D.
|title= Back on Track: The Global Rail Revival
|date= April 1994
|url= http://www.worldwatch.org/node/872
|accessdate= 2007-02-15
|journal=
|archive-url= https://web.archive.org/web/20061204005745/http://www.worldwatch.org/node/872
|archive-date= 2006-12-04
|url-status= dead
}}</ref><ref>{{cite web
|author= Schwartzman, Peter
|title= TRUCKS VS. TRAINS—WHO WINS?
|url =http://www.thezephyr.com/environ/trucktrain.html
|accessdate= 2007-02-15}}</ref> With the use of electric trains and cars in transportation there is the opportunity to run them with [[low-carbon power]], producing far fewer emissions.
===Urban planning===
{{Main|Urban planning}}
{{See|Carfree city}}
[[File:BikesInAmsterdam 2004 SeanMcClean.jpg|right|thumb|[[Bicycle]]s have almost no [[carbon footprint]] compared to cars, and canal transport may represent a positive option for certain types of freight in the 21st century.<ref>{{cite web|title=The Future of the Canals|url=http://www.canalmuseum.org.uk/education/teacher/lessonplan-future.pdf|publisher=London Canal Museum|accessdate=8 September 2013}}</ref>]]
Effective [[urban planning]] to reduce [[urban sprawl|sprawl]] aims to decrease Vehicle Miles Travelled (VMT), lowering emissions from transportation. Personal cars are extremely inefficient at moving passengers, while [[public transport]] and bicycles are many times more efficient (as is the simplest form of human transportation, walking). All of these are encouraged by urban/community planning and are an effective way to reduce greenhouse gas emissions. Inefficient [[land use]] development practices have increased infrastructure costs as well as the amount of energy needed for transportation, community services, and buildings.
At the same time, a growing number of citizens and government officials have begun advocating a smarter approach to land use planning. These [[smart growth]] practices include compact community development, multiple transportation choices, mixed land uses, and practices to conserve green space. These programs offer environmental, economic, and quality-of-life benefits; and they also serve to reduce energy usage and greenhouse gas emissions.
Approaches such as [[New Urbanism]] and [[transit-oriented development]] seek to reduce distances travelled, especially by private vehicles, encourage [[public transit]] and make [[walking]] and [[cycling]] more attractive options. This is achieved through "medium-density", [[mixed-use development|mixed-use planning]] and the concentration of housing within walking distance of [[town center]]s and [[transport node]]s.<!--Energy usage comparisons done in the book "Sustainability and Cities" by Peter Newman and Jeff Kentworthy.-->
Smarter growth land use policies have both a direct and indirect effect on energy consuming behavior. For example, transportation energy usage, the number one user of petroleum fuels, could be significantly reduced through more compact and mixed use land development patterns, which in turn could be served by a greater variety of non-automotive based transportation choices.
====Building design====
{{Main|Sustainable architecture|Green building}}
Emissions from [[house|housing]] are substantial,<ref>{{cite web|url=http://www.est.org.uk/myhome/climatechange/stats/homeenvironment/ |title=Energy Saving Trust: Home and the environment |publisher=[[Energy Saving Trust]] |accessdate=2010-08-26}}</ref> and government-supported energy efficiency programmes can make a difference.<ref>{{cite news
|last= Osborne
|first= Hilary
|title= Energy efficiency 'saves £350m a year'
|newspaper= Guardian Unlimited
|date= 2005-08-02
|url= http://money.guardian.co.uk/utilities/story/0,11992,1541051,00.html?gusrc=ticker-103704
|location=London}}</ref>
New buildings can be constructed using [[passive solar building design]], [[low-energy building]], or [[zero-energy building]] techniques, using [[renewable heat]] sources. Existing buildings can be made more efficient through the use of insulation, high-efficiency appliances (particularly [[water heating|hot water heaters]] and [[furnaces]]), [[insulated glazing|double- or triple-glazed gas-filled windows]], external window shades, and building orientation and siting. Renewable heat sources such as [[geothermal heat pump|shallow geothermal]] and [[passive solar]] energy reduce the amount of greenhouse gasses emitted. In addition to designing buildings which are more energy-efficient to heat, it is possible to design buildings that are more energy-efficient to cool by using lighter-coloured, more reflective materials in the development of urban areas (e.g. by painting roofs white) and planting trees.<ref>{{cite web
|first1 = Arthur H.
|last1 = Rosenfeld
|first2 = Joseph J.
|last2 = Romm
|first3 = Hashem
|last3 = Akbari
|first4 = Alan C.
|last4 = Lloyd
|website = Painting the Town White – and Green
|title = Technology Review
|date = February–March 1997
|publisher = Massachusetts Institute of Technology
|url = http://eande.lbl.gov/HeatIsland/PUBS/PAINTING/
|access-date = 2005-11-21
|archive-url = https://web.archive.org/web/20051108224203/http://eande.lbl.gov/HeatIsland/PUBS/PAINTING/
|archive-date = 2005-11-08
|url-status = dead
}}</ref><ref>{{cite book|author1=Committee on Science, Engineering |author2=Public Policy|title=Policy Implications of Greenhouse Warming: Mitigation, Adaptation, and the Science Base |publisher=National Academy Press|place= Washington, D.C.|year=1992|isbn= 978-0-309-04386-1}}</ref> This saves energy because it cools buildings and reduces the [[urban heat island]] effect thus reducing the use of air conditioning.
===Societal controls===
{{Main|Personal carbon credits}}
Another method being examined is to make carbon a new currency by introducing tradeable "[[personal carbon credits]]". The idea being it will encourage and motivate individuals to reduce their 'carbon footprint' by the way they live. Each citizen will receive a free annual quota of carbon that they can use to travel, buy food, and go about their business. It has been suggested that by using this concept it could actually solve two problems; pollution and poverty, old age pensioners will actually be better off because they fly less often, so they can cash in their quota at the end of the year to pay heating bills and so forth.{{citation needed|reason=previous source deadlink|date=April 2009}}
====Population====
Various organizations{{cn|date=November 2019}} promote [[human population planning]] as a means for mitigating global warming.<ref>[http://www.populationconnection.org/site/PageServer?pagename=about_us Population Connection] {{Webarchive|url=https://web.archive.org/web/20150111052139/http://www.populationconnection.org/site/PageServer?pagename=about_us |date=2015-01-11 }} Statement of Policy</ref> Proposed measures include improving access to [[family planning]] and [[reproductive health]] care and information, reducing [[natalistic politics]], public education about the consequences of continued population growth, and improving access of women to education and economic opportunities.
According to a 2017 study published in [[Environmental Research Letters]], having one less child would have a much more substantial effect on greenhouse gas emissions compared with for example living car free or eating a plant-based diet.<ref name=Wynes-Nicholas-2017 /> However this has been criticised: both as a [[category mistake]] for assigning descendants emissions to their ancestors<ref>{{Cite web|url=https://www.vox.com/energy-and-environment/2017/7/14/15963544/climate-change-individual-choices|title=The best way to reduce your personal carbon emissions: don't be rich|last=Roberts|first=David|date=2017-07-14|website=Vox|language=en|access-date=2019-10-22}}</ref> and for the very long timescale of reductions.<ref>{{Cite news|url=https://www.theguardian.com/environment/2017/jul/12/want-to-fight-climate-change-have-fewer-children|title=Want to fight climate change? Have fewer children|first=Damian |last=Carrington |date=2017-07-12|work=The Guardian|access-date=2019-10-22|language=en-GB|issn=0261-3077}}</ref>
Population control efforts are impeded by there being somewhat of a taboo in some countries against considering any such efforts.<ref>[http://www.bmj.com/cgi/content/full/315/7120/1441 To the point of farce: a martian view of the hardinian taboo—the silence that surrounds population control] Maurice King, Charles Elliott BMJ</ref> Also, various religions [[religious views on birth control|discourage or prohibit]] some or all forms of [[birth control]]. Population size has a vastly different per capita effect on global warming in different countries, since the per capita production of anthropogenic greenhouse gases varies greatly by country.<ref>[http://www.sierraclub.org/population/factsheets/pop_and_globalwarming.asp Who is Heating Up the Planet? A Closer Look at Population and Global Warming] {{Webarchive|url=https://web.archive.org/web/20110822013306/http://www.sierraclub.org/population/factsheets/pop_and_globalwarming.asp |date=2011-08-22 }} from Sierra Club</ref>
==Costs and benefits==
{{update section|date=October 2019|reason=how risk of tipping points is dealt with}}
{{Main|Economics of climate change mitigation}}
Globally the benefits of keeping warming under 2 °C exceed the costs.<ref>{{harvnb|Sampedro|Smith|Arto|González-Eguino|2020}}.</ref> However some consider [[cost–benefit analysis]] unsuitable for analysing climate change mitigation as a whole, but still useful for analysing the difference between a 1.5 °C target and 2 °C.<ref name=":0" />
===Costs===
One way of estimating the cost of reducing emissions is by considering the likely costs of potential technological and output changes. Policy makers can compare the [[marginal abatement costs]] of different methods to assess the cost and amount of possible abatement over time. The marginal abatement costs of the various measures will differ by country, by sector, and over time.<ref name="stern" /> Mitigation costs will vary according to how and when emissions are cut: early, well-planned action will minimise the costs.<ref name="stern" />
Many economists estimate the cost of climate change mitigation at between 1% and 2% of [[gross domestic product|GDP]].<ref name=":0">{{Cite web|url=https://www.oxfordmartin.ox.ac.uk/blog/can-cost-benefit-analysis-grasp-the-climate-change-nettle-and-can-we-justify-ambitious-targets/|title=Can cost benefit analysis grasp the climate change nettle? And can we…|website=Oxford Martin School|language=en|access-date=2019-11-11}}</ref> In 2019, scientists from [[Australia]], and [[Germany]] presented the "One Earth Climate Model" showing how temperature increase can be limited to 1.5 °C for 1.7 trillion dollars a year.<ref>{{cite web |title=One Earth Climate Model |url=https://oneearth.uts.edu.au/ |website=One Earth Climate Model |publisher=University of Technology, Climate and Energy College, German Aerospace Center |accessdate=22 January 2019}}</ref><ref>{{cite news |last1=Chow |first1=Lorraine |title=DiCaprio-Funded Study: Staying Below 1.5ºC is Totally Possible |url=https://www.ecowatch.com/dicaprio-climate-change-2626634576.html |accessdate=22 January 2019 |agency=Ecowatch |date=21 January 2019}}</ref>
According to this study, a global investment of approximately $1.7 trillion per year would be needed to [[Paris Agreement|keep global warming below 1.5°C]]. The method used by the One Earth Climate Model does not resort to dangerous geo-engineering methods. Whereas this is a large sum, it is still far less than the [[energy subsidies|subsidies]] governments currently provided to the ailing fossil fuel industry, estimated at more than $5 trillion per year by the International Monetary Fund.<ref>[https://www.oneearth.org/the-one-earth-climate-model/ One Earth Climate Model]</ref><ref>[https://www.springer.com/de/book/9783030058425 Achieving the Paris Climate Agreement goals]</ref>
===Benefits===
By addressing climate change, we can avoid the costs associated with the [[effects of climate change]].
According to the [[Stern Review]], inaction can be as high as the equivalent of losing at least 5% of global gross domestic product (GDP) each year, now and forever (up to 20% of the GDP or more when including a wider range of risks and impacts), whereas mitigating climate change will only cost about [[Stern_Review#Stern's_later_comments|2% of the GDP]].
Also, delaying to take significant reductions in greenhouse gas emissions may not be a good idea, when seen from a financial perspective.<ref>[https://theconversation.com/inaction-on-climate-change-risks-leaving-future-generations-530-trillion-in-debt-81134 Inaction on climate change risks leaving future generations $530 trillion in debt]</ref><ref>[https://www.earth-syst-dynam.net/8/577/2017/ Young people's burden: requirement of negative CO2 emissions]</ref>
The research organization Project Drawdown identified global climate solutions and ranked them according to their benefits.<ref>{{Cite web|url=https://www.drawdown.org/solutions-summary-by-rank|title=Summary of Solutions by Overall Rank|date=2017-04-05|website=Drawdown|language=en|access-date=2020-02-12}}</ref> Early deaths due to fossil fuel [[air pollution]] with a temperature rise to 2 °C cost more globally than mitigation would: and in India cost 4 to 5 times more.<ref>{{harvnb|Sampedro|Smith|Arto|González-Eguino|2020}}.</ref>
===Sharing===
One of the aspects of mitigation is how to share the costs and benefits of mitigation policies. In terms of the politics of mitigation, the UNFCCC's ultimate objective is to stabilize concentrations of GHG in the atmosphere at a level that would [[Avoiding Dangerous Climate Change|prevent "dangerous" climate change]] (Rogner ''et al.'', 2007).<ref>{{cite book
|year=2007
|author=Rogner, H.-H.
|title=Executive Summary. In (book chapter): Introduction. In: Climate Change 2007: Mitigation. Contribution of Working Group III to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change (B. Metz ''et al.'' (eds))
|url=http://www.ipcc.ch/publications_and_data/ar4/wg3/en/ch1s1-es.html
|publisher=Print version: Cambridge University Press, Cambridge, United Kingdom and New York, NY. Web version: IPCC website
|isbn=978-0-521-88011-4
|accessdate=2010-05-05|display-authors=etal}}</ref>
Rich people tend to emit more GHG than poor people.<ref name=banuri>{{cite book
|year=1996
|author=Banuri, T.
|title=Equity and Social Considerations. In: Climate Change 1995: Economic and Social Dimensions of Climate Change. Contribution of Working Group III to the Second Assessment Report of the Intergovernmental Panel on Climate Change (J.P. Bruce ''et al''. Eds.)
|publisher=This version: Printed by Cambridge University Press, Cambridge, UK, and New York, NY, US. PDF version: IPCC website
|url=https://archive.org/details/climatechange1990000unse_h1m9
|isbn=978-0-521-56854-8
|doi=10.2277/0521568544
|display-authors=etal
|url-access=registration
}}</ref> Activities of the poor that involve emissions of GHGs are often associated with basic needs, such as [[cooking]]. For richer people, emissions tend to be associated with things such as eating [[beef]], [[car]]s, [[Frequent-flyer program|frequent flying]], and [[Heating, ventilation, and air conditioning|home heating]].<ref>{{Cite web|url=https://www.theccc.org.uk/publication/behaviour-change-public-engagement-and-net-zero-imperial-college-london/|title=Behaviour change, public engagement and Net Zero (Imperial College London)|website=Committee on Climate Change|language=en-US|access-date=2019-11-21}}</ref> The impacts of cutting emissions could therefore have different impacts on human [[welfare economics|welfare]] according to wealth.
====Distributing emissions abatement costs====
There have been different proposals on how to allocate responsibility for cutting emissions (Banuri ''et al.'', 1996, pp. 103–105):<ref name=banuri/>
*'''[[Egalitarianism]]''': this system interprets the problem as one where each person has equal rights to a global resource, i.e., polluting the atmosphere.
*'''Basic needs''': this system would have emissions allocated according to basic needs, as defined according to a minimum level of [[consumption (economics)|consumption]]. Consumption above basic needs would require countries to buy more emission rights. From this viewpoint, developing countries would need to be at least as well off under an emissions control regime as they would be outside the regime.
*'''Proportionality and polluter-pays principle''': Proportionality reflects the ancient [[Aristotelianism|Aristotelian]] principle that people should receive in proportion to what they put in, and pay in proportion to the damages they cause. This has a potential relationship with the "polluter-pays principle", which can be interpreted in a number of ways:
**''Historical responsibilities'': this asserts that allocation of emission rights should be based on patterns of past emissions. Two-thirds of the stock of GHGs in the atmosphere at present is due to the past actions of developed countries (Goldemberg ''et al.'', 1996, p. 29).<ref name=goldemberg>{{cite book
|year=1996
|author=Goldemberg, J.
|title=Introduction: scope of the assessment. In: Climate Change 1995: Economic and Social Dimensions of Climate Change. Contribution of Working Group III to the Second Assessment Report of the Intergovernmental Panel on Climate Change (J.P. Bruce ''et al''. Eds.)
|publisher=This version: Printed by Cambridge University Press, Cambridge, UK, and New York, NY, US. Web version: IPCC website
|url=https://archive.org/details/climatechange1990000unse_h1m9
|isbn=978-0-521-56854-8
|doi=10.2277/0521568544
|display-authors=etal
|url-access=registration
}}</ref>
**''Comparable burdens and ability to pay'': with this approach, countries would reduce emissions based on comparable burdens and their ability to take on the costs of reduction. Ways to assess burdens include monetary costs per head of population, as well as other, more complex measures, like the [[UNDP]]'s [[Human Development Index]].
**''[[Willingness to pay]]'': with this approach, countries take on emission reductions based on their ability to pay along with how much they benefit{{cn|date=November 2019}} from reducing their emissions.
====Specific proposals====
*'''Ad hoc''': Lashof (1992) and Cline (1992) (referred to by Banuri ''et al.'', 1996, p. 106),<ref name=banuri/> for example, suggested that allocations based partly on [[GNP]] could be a way of sharing the burdens of emission reductions. This is because GNP and economic activity are partially tied to carbon emissions.
*'''Equal per capita entitlements''': this is the most widely cited method of distributing abatement costs, and is derived from egalitarianism (Banuri ''et al.'', 1996, pp. 106–107). This approach can be divided into two categories. In the first category, emissions are allocated according to national population. In the second category, emissions are allocated in a way that attempts to account for historical (cumulative) emissions.
*'''Status quo''': with this approach, historical emissions are ignored, and current emission levels are taken as a status quo right to emit (Banuri ''et al.'', 1996, p. 107). An analogy for this approach can be made with [[fishery|fisheries]], which is a common, limited resource. The analogy would be with the atmosphere, which can be viewed as an exhaustible [[natural resource]] (Goldemberg ''et al.'', 1996, p. 27).<ref name=goldemberg/> In [[international law]], one state recognized the long-established use of another state's use of the fisheries resource. It was also recognized by the state that part of the other state's economy was dependent on that resource.
==Governmental and intergovernmental action==
{{Main|Politics of global warming}}
{{See also|Global warming#Political response}}
{{further|Global Climate Action (portal)}}
{{Reduced pull quote|1=right
|2=Bringing down emissions of greenhouse gases asks a good deal of people, not least that they accept the science of climate change. It requires them to make sacrifices today so that future generations will suffer less, and to weigh the needs of people who are living far away.
|3=''[[The Economist]]''|4=28 November 2015<ref>Article [https://www.economist.com/news/special-report/21678962-how-farmers-poor-countries-are-responding-climate-change-if-you-cant-stand-heat "Adaptation. If you can't stand the heat"], ''[[The Economist]]'', special report on "Climate change", 28 November 2015, page 10-12.</ref>}}
In 2019 a report was published by the [[United Nations]] saying that to limit the temperature rise to 2 °C, the world will need to cut emissions by 2.7% each year from 2020 to 2030, and triple the climate targets. To limit the temperature rise to 1.5 °C the world would need to cut emissions by 7.6% each year from 2020 to 2030 and increase its climate commitments five-fold. Even if all the [[Paris Agreement]] pledges as they are in 2019, are fulfilled the temperature will rise by 3.2 degrees this century<ref>{{cite news |last1=Harvey |first1=Fiona |title=UN calls for push to cut greenhouse gas levels to avoid climate chaos |url=https://www.theguardian.com/environment/2019/nov/26/united-nations-global-effort-cut-emissions-stop-climate-chaos-2030 |accessdate=27 November 2019 |agency=The Guardian |date=26 November 2019}}</ref><ref>{{cite web |title=Cut Global Emissions by 7.6 Percent Every Year for Next Decade to Meet 1.5°C Paris Target - UN Report |url=https://unfccc.int/news/cut-global-emissions-by-76-percent-every-year-for-next-decade-to-meet-15degc-paris-target-un-report |website=United Nations Framework Convention on Climate Change |publisher=United Nations |accessdate=27 November 2019}}</ref>.
A report published in September 2019 before the [[2019 UN Climate Action Summit]] says, that the full implementation of all pledges made by international coalitions, countries, cities, regions and businesses (not only those in the Paris Agreement) will be sufficient to limit temperature rise to 2 degrees but not to 1.5 degrees.<ref>{{cite web |title=Global climate action from cities, regions and businesses – 2019 |url=https://newclimate.org/2019/09/18/global-climate-action-from-cities-regions-and-businesses-2019/ |website=New Climate Institute |date=17 September 2019 |accessdate=15 December 2019}}</ref> Additional pledges were made in the September climate summit<ref>{{cite news|url=https://www.climatechangenews.com/2019/10/02/world-promised-un-climate-action-summit/|title=This is what the world promised at the UN climate action summit|last1=Farland|first1=Chloe|date=2019-10-02|work=|accessdate=15 December 2019|url-status=live|agency=Climate Home News}}</ref> and in December.<ref>{{cite web |title=Global Climate Action Presents a Blueprint for a 1.5-Degree World |url=https://unfccc.int/news/global-climate-action-presents-a-blueprint-for-a-15-degree-world |website=UNFCCC |accessdate=15 December 2019}}</ref> All the information about all climate pledges is sent to the [[Global Climate Action Portal - Nazca]]. The scientific community is checking their fulfillment.<ref>{{cite web |title=Global Data Community Commits to Track Climate Action |url=https://unfccc.int/news/global-data-community-commits-to-track-climate-action |website=UNFCCC |accessdate=15 December 2019}}</ref>
===Paris agreement and Kyoto Protocol===
{{Main|Paris Agreement|Kyoto Protocol}}
[[File:Mitigation pathways.svg|thumb|upright=1.35|right|alt=Refer to caption and image description|The graph shows multiple pathways to limit climate change to 1.5 °C or 2 °C. All pathways include negative emission technologies such as afforestation and [[bio-energy with carbon capture and storage]].]]
The main current international agreement on combating climate change is the [[Paris agreement]]. The Paris Agreement's long-term temperature goal is to keep the increase in global average temperature to well below 2°C above pre-industrial levels; and to pursue efforts to limit the increase to 1.5°C. Each country must determine, plan, and regularly report on the contribution that it undertakes to mitigate global warming.<ref>{{Cite web|url=https://unfccc.int/resource/bigpicture/|title=UNFCCC eHandbook: Summary of the Paris Agreement|last=|first=|date=|website=unfccc.int|language=en|url-status=live|archive-url=|archive-date=|access-date=2019-11-12}}</ref> Climate change mitigation measures can be written down in national environmental policy documents like the [[Intended nationally determined contributions|nationally determined contributions (NDC)]].
The Paris agreement succeeds the 1997 [[Kyoto Protocol]] which expires in 2020, and is an [[wikt:amendment|amendment]] to the United Nations Framework Convention on Climate Change (UNFCCC). [[List of Kyoto Protocol signatories|Countries that ratified the Kyoto protocol]] committed to reduce their emissions of [[carbon dioxide]] and five other greenhouse gases, or engage in [[emissions trading]] if they maintain or increase emissions of these gases.
How well each individual country is on track to achieving its Paris agreement commitments can be followed on-line.<ref>[https://climateactiontracker.org/countries/ Climate Action Tracker]</ref>
=== Additional commitments ===
Except the main agreements there are many additional pledges made by international coalitions, countries, cities, regions and businesses. According to a report published in september 2019 before the [[2019 UN Climate Action Summit]], full implementation of all pledges, including those in the Paris Agreement, will be sufficient to limit temperature rise to 2 degrees but not to 1.5 degrees.<ref>{{cite web |title=Global climate action from cities, regions and businesses – 2019 |url=https://newclimate.org/2019/09/18/global-climate-action-from-cities-regions-and-businesses-2019/ |website=New Climate Institute |date=17 September 2019 |accessdate=15 December 2019}}</ref> After the report was published, additional pledges were made in the september climate summit<ref>{{cite news|url=https://www.climatechangenews.com/2019/10/02/world-promised-un-climate-action-summit/|title=This is what the world promised at the UN climate action summit|last1=Farland|first1=Chloe|date=2019-10-02|work=|accessdate=15 December 2019|url-status=live|agency=Climate Home News}}</ref> and in december of that year.<ref>{{cite web |title=Global Climate Action Presents a Blueprint for a 1.5-Degree World |url=https://unfccc.int/news/global-climate-action-presents-a-blueprint-for-a-15-degree-world |website=UNFCCC |accessdate=15 December 2019}}</ref>
All the information about the pledges is collected and analyzed in the [[Global Climate Action (portal)]], what is facilitating to the scientific community to check their fulfillment<ref>{{cite web |title=Global Data Community Commits to Track Climate Action |url=https://unfccc.int/news/global-data-community-commits-to-track-climate-action |website=UNFCCC |accessdate=15 December 2019}}</ref>
===Temperature targets===
Human activities are estimated to have caused approximately 1.0 °C of global warming above
pre-industrial levels, with a likely range of 0.8 °C to 1.2 °C. <ref>{{harvnb|IPCC SR15 Summary for Policymakers|2018|p=4}}</ref>
There is disagreement among experts over whether or not the 2 °C target can be met.<ref>Oppenheimer, M., ''et al.'', Section 19.7.2: Limits to Mitigation, in: [http://ipcc-wg2.gov/AR5/images/uploads/WGIIAR5-Chap19_FGDall.pdf Chapter 19: Emergent risks and key vulnerabilities] (archived [https://web.archive.org/web/20140701114626/http://ipcc-wg2.gov/AR5/images/uploads/WGIIAR5-Chap19_FGDall.pdf July 8 2014]), pp. 49–50, in {{harvnb|IPCC AR5 WG2 A|2014}}</ref>
; Official long-term target of 1.5 °C
In 2015, two official UNFCCC scientific expert bodies came to the conclusion that, "in some regions and vulnerable ecosystems, high risks are projected even for warming above 1.5 °C".<ref>{{cite web
|title= Report on the structured expert dialogue on the 2013–2015 review
|publisher= UNFCCC, Subsidiary Body for Scientific and Technological Advice & Subsidiary Body for Implementation
|date= 2015-04-04
|url= http://unfccc.int/resource/docs/2015/sb/eng/inf01.pdf
|accessdate= 2016-06-21}}</ref> This expert position was, together with the strong diplomatic voice of the poorest countries and the island nations in the Pacific, the driving force leading to the decision of the [[2015 United Nations Climate Change Conference|Paris Conference]] 2015, to lay down this 1.5 °C long-term target on top of the existing 2 °C goal.<ref>{{cite web
|title= 1.5°C temperature limit – key facts
|publisher= Climate Analytics
|url= http://climateanalytics.org/hot-topics/1-5c-key-facts.html
|accessdate= 2016-06-21
|archive-url= https://web.archive.org/web/20160630193348/http://climateanalytics.org/hot-topics/1-5c-key-facts.html
|archive-date= 2016-06-30
|url-status= dead
}}</ref>
===Encouraging use changes===
[[File:People's Climate Solidarity March crossing the Mississippi (34309653166).jpg|thumb|Citizens for climate action at the [[People's Climate March (2017)]].]]
====Emissions tax====
{{See also|carbon tax|energy tax|carbon fee and dividend}}
An emissions tax on greenhouse gas emissions requires emitters to pay a fee, charge or tax for every tonne of greenhouse gas released into the atmosphere.<ref name="gupta emissions tax">
{{cite book
|year=2007
|contribution=13.2.1.2 Taxes and charges
|title=Policies, instruments, and co-operative arrangements
|series=Climate Change 2007: Mitigation. Contribution of Working Group III to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change
|editor=B. Metz
|publisher=Print version: Cambridge University Press, Cambridge, UK, and New York, NY. This version: IPCC website
|author=Gupta, S.
|url=http://www.ipcc.ch/publications_and_data/ar4/wg3/en/ch13s13-2-1-2.html
|accessdate=2010-03-18
|display-authors=etal
|display-editors=etal
|archive-url=https://web.archive.org/web/20101029221927/http://www.ipcc.ch/publications_and_data/ar4/wg3/en/ch13s13-2-1-2.html
|archive-date=2010-10-29
|url-status=dead
}}
</ref> Most environmentally related taxes with implications for greenhouse gas emissions in OECD countries are levied on energy products and motor vehicles, rather than on CO<sub>2</sub> emissions directly.<ref name="gupta emissions tax"/> As such, non-transport sectors as the agricultural sector which produces large amounts of methane are typically left untaxed by current policies. Also, revenue of the emissions taxes are not always used to [[Emissions trading|offset the emissions directly]].<ref>{{cite web
|year=2000
|author1=Vourc'h, A. |author2=M. Jimenez
|title=Enhancing Environmentally Sustainable Growth in Finland. Economics Department Working Papers No. 229
|publisher=OECD website
|url=http://www.oecd.org/dataoecd/21/10/1880843.pdf
|accessdate=2010-04-21}}</ref><ref>{{cite web |last=Hyun-cheol |first= Kim |title=Carbon Tax to Be Introduced in 2010 |work= The Korea Times |date= August 22, 2008
|url= https://www.koreatimes.co.kr/www/news/biz/2008/11/123_29803.html |accessdate= August 4, 2010}}</ref>
Emission taxes can be both cost-effective and environmentally effective.<ref name="gupta emissions tax"/> Difficulties with emission taxes include their potential unpopularity, and the fact that they cannot guarantee a particular level of emissions reduction.<ref name="gupta emissions tax"/> Emissions or energy taxes also often fall disproportionately on lower income classes.{{cn|date=November 2019}} In developing countries, institutions may be insufficiently developed for the collection of emissions fees from a wide variety of sources.<ref name="gupta emissions tax"/>
====Investment====
{{See also|Fossil fuel divestment}}
Another indirect method of encouraging uses of renewable energy, and pursue sustainability and environmental protection, is that of prompting investment in this area through legal means, something that is already being done at national level as well as in the field of international investment.<ref>{{cite journal|last1=Farah|first1=Paolo Davide|title=Sustainable Energy Investments and National Security: Arbitration and Negotiation Issues|journal=Journal of World Energy Law and Business|date=2015|volume=8|issue=6|ssrn=2695579|accessdate=}}</ref>
Although state policies tackling climate change are seen as a threat to investors, so is global warming itself. As well as a policy risk, [[Ernst & Young|Ernst and Young]] identify physical, secondary, liability, transitional and reputation-based risks.<ref>{{Cite book|url=https://www.ey.com/Publication/vwLUAssets/EY-climate-change-and-investment/$FILE/EY-climate-change-and-investment.pdf|title=Climate Change: The Investment Perspective|last=|first=|publisher=Ernst and Young|year=2016|isbn=|location=|pages=2}}</ref> Therefore, it is increasingly seen to be in the interest of investors to accept climate change as a real threat which they must proactively and independently address.
====Carbon emissions trading====
{{Main|Carbon emissions trading}}
With the creation of a [[market (economics)|market]] for [[carbon emissions trading|trading carbon dioxide emissions]] within the Kyoto Protocol, it is likely that London financial markets will be the centre for this potentially highly lucrative business; the [[NYSE|New York]] and [[Chicago Stock Exchange|Chicago]] stock markets may have a lower trade volume than expected as long as the US maintains its rejection of the [[Kyoto Protocol|Kyoto]].<ref>[http://observer.guardian.co.uk/focus/story/0,,1509761,00.html How high-pressure politics threatens action on climate] The Observer June 2005</ref>
However, emissions trading may delay the phase-out of fossil fuels.<ref>''StoryOfStuff.com'' (2009) [http://storyofstuff.com/capandtrade/ "The Story of Cap and Trade"] {{Webarchive|url=https://web.archive.org/web/20100722034154/http://www.storyofstuff.com/capandtrade/ |date=2010-07-22 }}</ref>
In the north-east United States, a successful cap and trade program has shown potential for this solution.<ref>{{cite web|url=http://scienceprogress.org/2013/02/success-of-northeast-cap-and-trade-system-shows-market-based-climate-policy-is-well-within-reach/|title=Success of Northeast Cap-and-Trade System Shows Market-Based Climate Policy Is Well Within Reach}}</ref>
The [[European Union Emission Trading Scheme]] (EU ETS)<ref>[http://ec.europa.eu/environment/climat/emission.htm Emission Trading Scheme (EU ETS)] from ''ec.europa.eu''</ref> is the largest multi-national, greenhouse gas emissions trading scheme in the world. It commenced operation on 1 January 2005, and all 28 member states of the [[European Union]] participate in the scheme which has created a new market in carbon dioxide allowances estimated at 35 billion Euros (US$43 billion) per year.<ref>[http://www.opendemocracy.net/globalization-climate_change_debate/2570.jsp The $20,000,000,000,000 question] {{Webarchive|url=https://web.archive.org/web/20050615002442/http://www.opendemocracy.net/globalization-climate_change_debate/2570.jsp |date=2005-06-15 }} ''Robins, Nick'' for Opendemocracy</ref> The [[Chicago Climate Exchange]] was the first (voluntary) emissions market, and is soon to be followed by Asia's first market ([[Asia Carbon Exchange]]). A total of 107 million metric tonnes of carbon dioxide equivalent have been exchanged through projects in 2004, a 38% increase relative to 2003 (78 Mt CO<sub>2</sub>e).<ref>[http://carbonfinance.org/docs/CarbonMarketStudy2005.pdf State and Trends of the Carbon Market] International Emissions Trading Association 2005</ref>
Twenty three [[multinational corporation]]s have come together in the [[G8 Climate Change Roundtable]], a business group formed at the January 2005 [[World Economic Forum]]. The group includes [[Ford Motor Company|Ford]], [[Toyota]], [[British Airways]], and [[BP]]. On 9 June 2005 the Group published a statement<ref>[http://www.weforum.org/pdf/g8_climatechange.pdf Statement of G8 Climate Change Roundtable] {{webarchive |url=https://web.archive.org/web/20130508123035/http://www.weforum.org/pdf/g8_climatechange.pdf |date=May 8, 2013}} Convened by the World Economic Forum June 2005</ref> stating that there was a need to act on climate change and claiming that market-based solutions can help. It called on governments to establish "clear, transparent, and consistent price signals" through "creation of a long-term policy framework" that would include all major producers of greenhouse gases.
The [[Regional Greenhouse Gas Initiative]] is a proposed carbon trading scheme being created by nine North-eastern and Mid-Atlantic [[United States|American]] states; [[Connecticut]], [[Delaware]], [[Maine]], [[Massachusetts]], [[New Hampshire]], [[New Jersey]], [[New York (state)|New York]], [[Rhode Island]], and [[Vermont]]. The scheme was due to be developed by April 2005 but has not yet been completed.
===Implementation===
[[File:Total CO2 by Region.svg|thumb|upright=1.35|Since 2000, rising {{CO2}} emissions in China and the rest of world have eclipsed the output of the United States and Europe.<ref name="Friedlingstein 2019">{{harvnb|Friedlingstein|Jones|O'Sullivan|Andrew|2019}}, Table 7.</ref>]]
[[File:Per Capita CO2 by Region.svg|thumb|upright=1.35|Per person, the United States generates carbon dioxide at a far faster rate than other primary regions.<ref name="Friedlingstein 2019"/>]]
Implementation puts into effect climate change mitigation strategies and targets. These can be targets set by international bodies or voluntary action by individuals or institutions. This is the most important, expensive and least appealing aspect of environmental governance.<ref name="Evans">Evans. J (forthcoming 2012) Environmental Governance, Routledge, Oxon</ref>
====Funding====
{{main|Climate Finance}}
Funding, such as the [[Green Climate Fund]], is often provided by nations, groups of nations and increasingly NGO and private sources. These funds are often channelled through the Global Environmental Facility (GEF). This is an environmental funding mechanism in the World Bank which is designed to deal with global environmental issues.<ref name="Evans"/> The GEF was originally designed to tackle four main areas: biological diversity, climate change, international waters and ozone layer depletion, to which [[land degradation]] and [[persistent organic pollutant]] were added. The GEF funds projects that are agreed to achieve global environmental benefits that are endorsed by governments and screened by one of the GEF's implementing agencies.<ref>Mee. L. D, Dublin. H. T, Eberhard. A. A (2008) Evaluating the Global Environment Facility: A goodwill gesture or a serious attempt to deliver global benefits?, Global Environmental Change 18, 800–810</ref>
====Research====
It has been estimated that only 0.12% of all funding for climate-related research is spent on the social science of climate change mitigation.<ref name=":02">{{Cite journal|last1=Overland|first1=Indra|last2=Sovacool|first2=Benjamin K.|date=2020-04-01|title=The misallocation of climate research funding|url=http://www.sciencedirect.com/science/article/pii/S2214629619309119|journal=Energy Research & Social Science|language=en|volume=62|pages=101349|doi=10.1016/j.erss.2019.101349|issn=2214-6296|doi-access=free}}</ref> Vastly more funding is spent on natural science studies of climate change and considerable sums are also spent on studies of impact of and adaptation to climate change.<ref name=":02" /> It has been argued that this is a misallocation of resources, as the most urgent puzzle at the current juncture is to work out how to change human behavior to mitigate climate change, whereas the natural science of climate change is already well established and there will be decades and centuries to handle adaptation.<ref name=":02" />
====Problems====
There are numerous issues which result in a current perceived lack of implementation.<ref name="Evans"/> It has been suggested that the main barriers to implementation are Uncertainty, Fragmentation, Institutional void, Short time horizon of policies and politicians and Missing motives and willingness to start adapting. The relationships between many climatic processes can cause large levels of uncertainty as they are not fully understood and can be a barrier to implementation. When information on climate change is held between the large numbers of actors involved it can be highly dispersed, context specific or difficult to access causing fragmentation to be a barrier. Institutional void is the lack of commonly accepted rules and norms for policy processes to take place, calling into question the legitimacy and efficacy of policy processes. The Short time horizon of policies and politicians often means that climate change policies are not implemented in favour of socially favoured societal issues. Statements are often posed to keep the illusion of political action to prevent or postpone decisions being made. Missing motives and willingness to start adapting is a large barrier as it prevents any implementation.<ref name="IHDP">Biesbroek. G.R, Termeer. C.J.A.M, Kabat. P, Klostermann.J.E.M (unpublished) Institutional governance barriers for the development and implementation of climate adaptation strategies, Working paper for the International Human Dimensions Programme (IHDP) conference "Earth System Governance: People, Places, and the Planet", December 2–4, Amsterdam, the Netherlands</ref> The issues that arise with a system which involves international government cooperation, such as [[emissions trading|cap and trade]], could potentially be improved with a polycentric approach where the rules are enforced by many small sections of authority as opposed to one overall enforcement agency.<ref>{{cite web |url=http://www10.iadb.org/intal/intalcdi/pe/2009/04268.pdf |title=A Polycentric Approach for Coping with Climate Change |publisher=World Bank |date=October 2009 |author=Elinor Ostrom |archiveurl=https://web.archive.org/web/20131101164212/http://www10.iadb.org/intal/intalcdi/pe/2009/04268.pdf |archivedate=2013-11-01 |series=Policy Research Working Paper Series}}</ref> Concerns about metal requirement and/or availability for essential decarbonization technoloqies such as [[photovoltaics]], [[nuclear power]], and (plug-in hybrid) [[electric vehicle]]s have also been expressed as obstacles.<ref name="Tokimatsu">{{cite journal|last1=Tokimatsu|first1=Koji|last2=Wachtmeister|first2=Henrik|last3=McLellan|first3=Benjamin|last4=Davidsson|first4=Simon|last5=Murakami|first5=Shinsuke|last6=Höök|first6=Mikael|last7=Yasuoka|first7=Rieko|last8=Nishio|first8=Masahiro|title=Energy modeling approach to the global energy-mineral nexus: A first look at metal requirements and the 2 °C target|journal=Applied Energy|date=December 2017|volume=207|pages=494–509|doi=10.1016/j.apenergy.2017.05.151}}</ref>
====Occurrence====
Despite a perceived lack of occurrence,{{clarify|date=October 2019}} evidence of implementation is emerging internationally. Some examples of this are the initiation of NAPA's and of joint implementation. Many developing nations have made National Adaptation Programs of Action (NAPAs) which are frameworks to prioritize adaption needs.<ref name="EMJ">Preston. B. L, Westaway. R. M, Yuen. E. Y (2004) Climate adaptation planning in practice: an evaluation of adaptation plans from three developed nations, European Management Journal, 22(3) 304–314</ref> The implementation of many of these is supported by GEF agencies.<ref>UNFCCC (2011) Report on the twentieth meeting of the Least Developed Countries Expert Group, Subsidiary Body for Implementation, United Nations Framework Convention on Climate Change</ref> Many developed countries are implementing 'first generation'{{clarify|date=November 2019}} institutional adaption plans particularly at the state and local government scale.<ref name="EMJ"/> There has also been a push towards joint implementation between countries by the UNFCCC as this has been suggested as a cost-effective way for objectives to be achieved.<ref>UNFCCC (2011) Annual report of the Joint Implementation Supervisory Committee to the Conference of the Parties serving as the meeting of the Parties to the Kyoto Protocol, United Nations Framework Convention on Climate Change</ref>
===Montreal protocol===
Although not designed for this purpose, the [[Montreal Protocol]] has benefited climate change mitigation efforts.<ref>{{cite journal
|date=20 March 2007
|journal=PNAS
|volume=104
|issue=12
|pages=4814–19
|author=Velders, G.J.M.
|title=The importance of the Montreal Protocol in protecting climate
|doi=10.1073/pnas.0610328104
|bibcode= 2007PNAS..104.4814V
|pmid=17360370
|pmc=1817831
|display-authors=etal
}}</ref> The Montreal Protocol is an international [[treaty]] that has successfully reduced emissions of [[ozone-depleting substance]]s (for example, [[Chlorofluorocarbon|CFCs]]), which are also greenhouse gases.
===Territorial policies===
Many countries are aiming for [[Carbon neutrality|net zero emissions]], and many have either [[carbon tax]]es or [[carbon emission trading]].
[[File:Carbon taxes and emission trading worldwide 2019.svg|alt=Carbon taxes and emission trading worldwide|thumb|upright=1.35|Emission trading and carbon taxes around the world (2019)<ref>{{Citation |author = World Bank Group |title = State and Trends of Carbon Pricing 2019 |date = 2019-06-06 |url = https://openknowledge.worldbank.org/handle/10986/31755 |lang = en}}</ref>
{{Legend|#009a3e|Carbon [[emission trading]] implemented or scheduled}}
{{Legend|#323b90|[[Carbon tax]] implemented or scheduled}}
{{Legend|#fbba00|Carbon [[emission trading]] or [[carbon tax]] under consideration}}]]
====United States====
{{Main|Climate change in the United States}}
Efforts to reduce [[greenhouse gas emissions by the United States]] include [[energy policy of the United States|energy policies]] which encourage efficiency through programs like [[Energy Star]], [[Commercial Building Integration]], and the [[Industrial Technologies Program]].<ref>{{cite web|url=http://www.eere.energy.gov/industry/bestpractices/index.html |title=Industrial Technologies Program: BestPractices |publisher=Eere.energy.gov |accessdate=2010-08-26}}</ref>
In the absence of substantial federal action, state governments have adopted emissions-control laws such as the [[Regional Greenhouse Gas Initiative]] in the Northeast and the [[Global Warming Solutions Act of 2006]] in California.<ref>{{cite news |url=https://www.nytimes.com/2012/10/14/science/earth/in-california-a-grand-experiment-to-rein-in-climate-change.html |work=The New York Times |first=Felicity |last=Barringer |title=In California, a Grand Experiment to Rein in Climate Change |date=2012-10-13}}</ref> In 2019 a new climate change bill was introduced in Minnesota. One of the targets, is making all the energy of the state carbon free, by 2030.<ref>{{cite news |last1=Kahn |first1=Brian |title=Minnesota Introduces Bold New Climate Change Bill Crafted by Teens |url=https://www.gizmodo.com.au/2019/04/minnesota-introduces-bold-new-climate-change-bill-crafted-by-teens/ |accessdate=15 April 2019 |agency=Gizmodo |date=April 13, 2019}}</ref>
==== China ====
{{main|Greenhouse gas emissions by China}}
As to 2019, China implements more than 100 policies to fight climate change. China said in the [[Paris Agreement]] that its emission will begin to fall by 2030, but it will possibly occur by 2026. This can position China as a leader on the issue because it is the biggest emitter of [[GHG emission]]s, so if it really reduces them, the significance will be large.<ref>{{cite web |last1=Sims Gallagher |first1=Kelly |last2=Zhang |first2=Fang |title=China is positioned to lead on climate change as the US rolls back its policies |url=https://theconversation.com/china-is-positioned-to-lead-on-climate-change-as-the-us-rolls-back-its-policies-114897 |website=The Conversation |accessdate=13 September 2019}}</ref>
==== European Union ====
{{Further|Climate change in Europe|Climate change in the European Union|European Commissioner for the Environment|European Climate Change Programme|European Green Deal}}
The climate commitments of the [[European Union]] are divided into 3 main categories: targets for the year 2020, 2030 and 2050. The European Union claim that their policies are in line with the goal of the [[Climate_change_mitigation#Paris_agreement_and_Kyoto_Protocol|Paris Agreement]].<ref>{{cite web |title=2050 long-term strategy |url=https://ec.europa.eu/clima/policies/strategies/2050_en |website=European Commission |accessdate=21 November 2019}}</ref><ref>{{cite web |title=Paris Agreement |url=https://ec.europa.eu/clima/policies/international/negotiations/paris_en |website=European Commission |accessdate=21 November 2019}}</ref>
'''Targets for the year 2020<ref>{{cite web |title=2020 climate & energy package |url=https://ec.europa.eu/clima/policies/strategies/2020_en |website=European Commission |accessdate=21 November 2019}}</ref>:'''
* Reduce GHG emissions by 20% from the level in 1990.
* Produce 20% of energy from renewable sources.
* Increase Energy Efficiency by 20%.
'''Targets for the year 2030<ref>{{cite web |title=2030 climate & energy framework |url=https://ec.europa.eu/clima/policies/strategies/2030_en |website=European Commission |accessdate=21 November 2019}}</ref>:'''
* Reduce GHG emission by 40% from the level of 1990. In 2019 The European Parliament adopted a resolution upgrading the target to 55%<ref>{{cite web |title=The European Parliament declares climate emergency |url=https://www.europarl.europa.eu/news/en/press-room/20191121IPR67110/the-european-parliament-declares-climate-emergency |website=European Parliament |accessdate=3 December 2019}}</ref>
* Produce 32% of energy from renewables.
* Increase energy efficiency by 32.5%.
'''Targets for the year 2050<ref>{{cite web |title=2050 long-term strategy |url=https://ec.europa.eu/clima/policies/strategies/2050_en |website=European Commission |accessdate=21 November 2019}}</ref>:'''
* Become climate neutral.
'''Implementation:'''
The European Union claims that he has already achieved the 2020 target for emission reduction and have the legislation needed to achieve the 2030 targets. Already in 2018, its GHG emissions were 23% lower that in 1990.<ref>{{cite web |title=Progress made in cutting emissions |url=https://ec.europa.eu/clima/policies/strategies/progress_en |website=European Commission |accessdate=21 November 2019}}</ref>
==== New Zealand ====
{{further|Climate change in New Zealand}}
New Zealand made significant pledges on climate change mitigation in the year 2019: reduce emissions to zero by 2050, plant 1 billion trees by 2028, and made high taxes on farmers who will not reduce emissions in 2025. Already in 2019 New Zealand banned new offshore oil and gas drilling and decided the climate change issues will be examined before every important decision.<ref>{{cite news |last1=Ainge Roy |first1=Eleanor |title=Climate change to steer all New Zealand government decisions from now on |url=https://www.theguardian.com/world/2019/dec/04/climate-change-to-steer-all-new-zealand-government-decisions-from-now-on |accessdate=4 December 2019 |agency=The Guardian |publisher=The Dunedin |date=4 December 2019}}</ref>
====Developing countries====
In order to reconcile [[economic development]] with mitigating carbon emissions, [[developing countries]] need particular support, both financial and technical. One of the means of achieving this is the Kyoto Protocol's [[Clean Development Mechanism]] (CDM). The [[World Bank]]'s Prototype Carbon Fund<ref>[http://carbonfinance.org/pcf/ Prototype Carbon Fund] from the World Bank Carbon Finance Unit</ref> is a [[public private partnership]] that operates within the CDM.
An important point of contention, however, is how [[overseas development]] assistance not directly related to climate change mitigation is affected by funds provided to climate change mitigation.<ref name=ODI>Jessica Brown, Neil Bird and Liane Schalatek (2010) [http://www.odi.org.uk/resources/details.asp?id=4931&title=climate-finance-additionality-definitions-implications Climate finance additionality: emerging definitions and their implications] [[Overseas Development Institute]]</ref> One of the outcomes of the UNFCC [[Copenhagen Climate Conference]] was the [[Copenhagen Accord]], in which developed countries promised to provide US$30 million between 2010 and 2012 of new and additional resources.<ref name=ODI/> Yet it remains unclear what exactly the definition of additional is and the [[European Commission]] has requested its member states to define what they understand to be additional, and researchers at the [[Overseas Development Institute]] have found four main understandings:<ref name=ODI/>
# Climate finance classified as aid, but additional to (over and above) the [[Millennium Development Goals#Funding commitment|'0.7%' ODA target]];
# Increase on previous year's [[Official Development Assistance]] (ODA) spent on climate change mitigation;
# Rising ODA levels that include climate change finance but where it is limited to a specified percentage; and
# Increase in climate finance not connected to ODA.
The main point being that there is a conflict between the [[OECD]] states budget deficit cuts, the need to help developing countries adapt to develop sustainably and the need to ensure that funding does not come from cutting aid to other important [[Millennium Development Goals]].<ref name=ODI/>
However, none of these initiatives suggest a quantitative cap on the emissions from developing countries. This is considered as a particularly difficult policy proposal as the economic growth of developing countries are proportionally reflected in the growth of greenhouse emissions. Critics{{Who|date=May 2010}} of mitigation often argue that, the developing countries' drive to attain a comparable living standard to the developed countries would doom the attempt at mitigation of global warming. Critics{{Who|date=May 2010}} also argue that holding down emissions would shift the human cost of global warming from a general one to one that was borne most heavily by the poorest populations on the planet.
In an attempt to provide more opportunities for developing countries to adapt clean technologies, [[UNEP]] and [[WTO]] urged the international community to reduce trade barriers and to conclude the [[Doha Development Round|Doha trade round]] "which includes opening trade in environmental goods and services".<ref>[https://www.un.org/apps/news/story.asp?NewsID=31278&Cr=trade&Cr1=environment# Free trade can help combat global warming, finds UN report] UN News Centre, 26 June 2009</ref>
In 2019 week of climate action in [[Latin America]] and the [[Caribbean]] result in a declaration in which leaders says that they will act to reduce emissions in the sectors of transportation, energy, urbanism, industry, forest conservation and land use and "sent a message of solidarity with all the people of Brazil suffering the consequences of the [[Deforestation of the Amazon rainforest|rainforest fires in the Amazon region]], underscoring that protecting the world's forests is a collective responsibility, that forests are vital for life and that they are a critical part of the solution to climate change".<ref>{{cite web |title=Latin America and Caribbean Climate Week 2019 Key Messages for the UN Climate Action Summit |url=https://unfccc.int/sites/default/files/resource/LACCW%202019%20Messages%20for%20UN%20Climate%20Action%20Summit.pdf |website=Latin America and Caribbean Climate Week 2019 |accessdate=25 August 2019}}</ref><ref>{{cite web |title=Latin American & Caribbean Climate Week Calls for Urgent, Ambitious Action |url=https://unfccc.int/news/latin-american-caribbean-climate-week-calls-for-urgent-ambitious-action |website=United Nations Climate Change |accessdate=25 August 2019}}</ref>
==Non-governmental approaches==
While many of the proposed methods of mitigating global warming require governmental funding, legislation and regulatory action, individuals and [[business action on climate change|businesses]] can also play a part in the mitigation effort.
===Choices in personal actions and business operations===
Environmental groups encourage [[individual and political action on climate change|individual action against global warming]], often aimed at the [[consumer]]. Common recommendations include lowering home heating and cooling usage, burning less gasoline, supporting renewable [[energy sources]], buying local products to reduce transportation, turning off unused devices, and various others.
A [[geophysicist]] at [[Utrecht University]] has urged similar institutions to hold the vanguard in voluntary mitigation, suggesting the use of communications technologies such as [[videoconferencing]] to reduce their dependence on long-haul flights.<ref>{{cite journal
|author=Andrew Biggin
|date=16 August 2007
|title=Scientific bodies must take own action on emissions
|journal=[[Nature (journal)|Nature]]
|volume=448
|issue=7155
|page=749
|doi=10.1038/448749a
|pmid=17700677
|bibcode= 2007Natur.448..749B|doi-access=free
}}</ref>
====Air travel and shipment====
{{update section|reason=CORSIA|date=October 2019}}
In 2008, climate scientist [[Kevin Anderson (scientist)|Kevin Anderson]] raised concern about the growing effect of rapidly increasing global air transport on the climate in a paper,<ref>{{cite journal
|last1=Anderson
|first1=K
|last2=Bows
|first2=A
|year=2008
|title= Reframing the climate change challenge in light of post-2000 emission trends
|journal=Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences
|volume=366 |issue=1882 |pages=3863–82
|doi=10.1098/rsta.2008.0138|pmid=18757271
|bibcode= 2008RSPTA.366.3863A}}</ref> and a presentation,<ref name="anderson">{{cite web
|last= Anderson
|first=K
|date=June 17, 2008
|url=http://transitionculture.org/wp-content/uploads/kevin-anderson-2.ppt
|title=Reframing climate change: from long-term targets to emission pathways
|quote= (esp. slide 24 onward)}}</ref> suggesting that reversing this trend is necessary to reduce emissions.
Part of the difficulty is that when [[environmental impact of aviation|aviation emissions]] are made at high altitude, the climate impacts are much greater than otherwise. Others have been raising the related concerns of the increasing [[hypermobility (travel)|hypermobility]] of individuals, whether traveling for business or pleasure, involving frequent and often long distance air travel, as well as air shipment of goods.<ref name="gossling">Gössling S, Ceron JP, Dubois G, Hall CM, Gössling IS, Upham P, [[Earthscan]] London (2009). Hypermobile travellers. and Implications for Carbon Dioxide Emissions Reduction. In: Climate Change and Aviation: Issues, Challenges and Solutions, London. The chapter: ''[https://alicante.academia.edu/documents/0076/1866/chap06_copy.pdf Chapter 6] {{webarchive|url=https://web.archive.org/web/20100619151427/http://alicante.academia.edu/documents/0076/1866/chap06_copy.pdf |date=2010-06-19}}''</ref>
===Business opportunities and risks===
{{Main|Business action on climate change}}
===Investor response===
{{Main|Fossil fuel divestment}}
Climate change is also a concern for large institutional investors who have a long term time horizon and potentially large exposure to the negative impacts of global warming because of the large geographic footprint of their multi-national holdings. [[Socially responsible investing]] funds allow investors to invest in funds that meet high ESG (environmental, social, governance) standards as such funds invest in companies that are aligned with these goals.<ref>{{cite web |url=http://www.kiplinger.com/article/investing/T041-C016-S001-5-mutual-funds-for-socially-responsible-investors.html |title=5 Mutual Funds for Socially Responsible Investors |publisher=Kiplinger}}</ref> [[Proxy firm]]s can be used to draft guidelines for [[investment manager]]s that take these concerns into account.<ref>{{cite web |url=http://www.ussif.org/files/publications/institutional_climate.pdf |title=Investing to Curb Climate Change |publisher=USSIF |page=2}}</ref>
===Legal action===
{{See also|Duty to rescue}}
In some countries, those affected by climate change may be able to sue major producers. Attempts at litigation have been initiated by entire peoples such as Palau<ref>{{cite web|url=https://www.pbs.org/wnet/need-to-know/video/video-paradise-lost/14421/|title=Video: Paradise lost? – Need to Know |publisher=PBS|quote=Palau suing the industrialized countries over global warming}}</ref> and the Inuit,<ref>[http://www.msnbc.msn.com/id/6908719/site/newsweek/ Inuit suing the US in regards to global warming] {{webarchive |url=https://web.archive.org/web/20100825135526/http://www.msnbc.msn.com/id/6908719/site/newsweek/ |date=August 25, 2010}}</ref> as well as non-governmental organizations such as the Sierra Club.<ref>{{cite web|url=http://www.newson6.com/story/9138384/environmental-integrity-project-sierra-club-announce-plans-to-sue-epa-unless-it-revises-nitrogen-oxide-emissions-standard-curbs-nitrous-oxide?clienttype=printable|title=Environmental Integrity Project, Sierra Club Announce Plans to Sue EPA Unless It Revises Nitrogen Oxide Emissions Standard, Curbs Nitrous Oxide Pollution Linked to Global Warming – NewsOn6.com – Tulsa, OK – News, Weather, Video and Sports – KOTV.com -|access-date=2013-02-19|archive-url=https://web.archive.org/web/20160111204839/http://www.newson6.com/story/9138384/environmental-integrity-project-sierra-club-announce-plans-to-sue-epa-unless-it-revises-nitrogen-oxide-emissions-standard-curbs-nitrous-oxide?clienttype=printable|archive-date=2016-01-11|url-status=dead}}</ref> Although proving that particular weather events are due specifically to global warming may never be possible,<ref>Edward Lorenz (1982): "Climate is what you expect, weather is what you get"</ref> methodologies have been developed to show the increased risk of such events caused by global warming.<ref>Stott, et al. (2004), "Human contribution to the European heatwave of 2003", Nature, Vol. 432, 2 December 2004</ref>
For a legal action for [[negligence]] (or similar) to succeed, "Plaintiffs ... must show that, more probably than not, their individual injuries were caused by the risk factor in question, as opposed to any other cause. This has sometimes been translated to a requirement of a relative risk of at least two."<ref>Grossman, Columbia J. of Env. Law, 2003</ref> Another route (though with little legal bite) is the [[World Heritage Convention]], if it can be shown that climate change is affecting [[World Heritage Site]]s like [[Mount Everest]].<ref>{{cite web|url=http://www.heatisonline.org/contentserver/objecthandlers/index.cfm?id=4950&method=full |title=Climate change 'ruining' Everest |publisher=Heatisonline.org |date=2004-11-17 |access-date=2010-08-26}}</ref><ref>[https://www.bbc.co.uk/caribbean/news/story/2004/11/041117_climate-belize.shtml Climate change 'ruining' Belize] BBC November 2004</ref>
Besides countries suing one another, there are also cases where people in a country have taken legal steps against their own government. Legal action for instance has been taken to try to force the [[United States Environmental Protection Agency|US Environmental Protection Agency]] to regulate greenhouse gas emissions under the [[Clean Air Act (United States)|Clean Air Act]],<ref>[http://www.climatelaw.org/cases Climate Justice] Ongoing Cases</ref> and against the [[Export-Import Bank of the United States|Export-Import Bank]] and [[Overseas Private Investment Corporation|OPIC]] for failing to assess environmental impacts (including global warming impacts) under [[NEPA]].{{Citation needed|date=September 2007}}
In the Netherlands and Belgium, organisations such as the foundation [[Urgenda]]<ref>{{cite news|url=https://www.theguardian.com/environment/2015/jun/24/dutch-government-ordered-cut-carbon-emissions-landmark-ruling|title=Dutch government ordered to cut carbon emissions in landmark ruling|first=Arthur Neslen The|last=Hague|date=24 June 2015|newspaper=The Guardian}}</ref><ref>{{cite web|url=http://www.urgenda.nl/themas/klimaat-en-energie/klimaatzaak/|title=Klimaat en Energie – Thema's – Urgenda – Samen Sneller Duurzaam}}</ref><ref>{{cite web|url=http://tegenlicht.vpro.nl/afleveringen/2015-2016/de-klimaatzaak.html|title=VPRO Tegenlicht}}</ref> and the [[vzw Klimaatzaak]] in Belgium<ref>{{cite web|url=http://deredactie.be/cm/vrtnieuws/binnenland/2.36678|title=Klimaatzaak}}</ref><ref>{{cite web|url=http://klimaatzaak.eu/nl/about/|title=Over ons – Klimaatzaak}}</ref> have also sued their governments as they believe their governments aren't meeting the emission reductions they agreed to. Urgenda have already won their case against the Dutch government.{{citation needed|date=July 2017}}
According to a 2004 study commissioned by [[Friends of the Earth]], [[ExxonMobil]], and its predecessors caused 4.7 to 5.3 percent of the world's man-made carbon dioxide emissions between 1882 and 2002. The group suggested that such studies could form the basis for eventual legal action.<ref>Press release (29 January 2004). [http://www.foe.co.uk/resource/press_releases/exxonmobils_contribution_t_28012004.html Archived press release: Exxonmobil's contribution to global warming revealed]. Friends of the Earth Trust. Retrieved May 25, 2015.</ref>
In 2015, [[Exxon]] received a subpoena. According to the ''Washington Post'' and confirmed by the company, the attorney general of New York, [[Eric Schneiderman]], opened an investigation into the possibility that the company had misled the public and investors about the risks of climate change.<ref>{{cite news|url=https://www.washingtonpost.com/news/energy-environment/wp/2015/11/05/exxonmobil-under-investigation-for-misleading-the-public-about-climate-change/ |title=New York is investigating Exxon Mobil for allegedly misleading the public about climate change |newspaper=The Washington Post |date=November 5, 2015 |access-date=December 29, 2015}}</ref> In October 2019, the trial began.<ref>{{cite news |last1=Cook |first1=John |last2=Supran |first2=Geoffrey |last3=Oreskes |first3=Naomi |last4=Maibach |first4=Ed |last5=Lewandowsky |first5=Stephan |title=Exxon has misled Americans on climate change for decades. Here's how to fight back |url=https://www.theguardian.com/commentisfree/2019/oct/23/exxon-climate-change-fossil-fuels-disinformation |accessdate=27 October 2019 |agency=The Guardian |date=24 October 2019}}</ref> [[Massachusetts]] sued Exxon also, for hiding the impact of climate change.<ref>{{cite news |last1=Hirji |first1=Zahra |title=Massachusetts Is Now The Second State Suing The Oil Giant Exxon Over Climate Change |url=https://www.buzzfeednews.com/article/zahrahirji/exxon-lawsuit-massachusetts-climate-change |accessdate=27 October 2019 |agency=Buzzfeed.news |date=October 24, 2019}}</ref>
In 2019, 22 states, six cities and [[Washington DC]] in [[United States]], sued the Trump administration for repealing the [[Clean Power Plan]].<ref>{{cite news |last1=Rosane |first1=Olivia |title=29 States and Cities Sue to Block Trump's 'Dirty Power' Rule |url=https://www.ecowatch.com/trump-clean-power-plan-lawsuits-2639814367.html |accessdate=15 August 2019 |agency=Ecowatch |date=14 August 2019}}</ref>
=== Activism ===
[[File:People's Climate March (26229656304).jpg|alt=Many people standing on steps of large public building holding banners with signs, including "Act For Climate" and "Go Nuclear."|thumb|Protesters at the Helsinki [[People's Climate March]]{{dn|date=April 2020}}, 29 November 2015]]
[[Environmental organization]]s organize different actions such as [[Peoples Climate March]]es and [[Divestment from fossil fuels]]. 1,000 organizations with a worth of 8 trillion dollars, made commitments to divest from fossil fuel to 2018.<ref>{{cite web |title=Major milestone: 1000+ divestment commitments |url=https://gofossilfree.org/major-milestone-1000-divestment-commitments/ |website=350.org |accessdate=17 December 2018}}</ref> Another form of action is [[climate strike]].<ref>{{cite news |last1=Josh Gabbatiss |first1=Josh |title=Teenage activist inspires school strikes to protest climate change after telling leaders they are 'not mature enough' |url=https://www.independent.co.uk/environment/greta-thunberg-school-strike-cop24-climate-change-global-warming-fossil-fuels-a8683376.html |accessdate=17 December 2018 |agency=The Independent |date=15 December 2018}}</ref> In January 2019 12,500 students marched in [[Brussels]] demanding [[Climate action]].<ref>{{cite web |last1=Conley |first1=Julia |title=I'm Sure Dinosaurs Thought They Had Time, Too': Over 12,000 Students Strike in Brussels Demanding Bold Climate Action |url=https://www.commondreams.org/news/2019/01/17/im-sure-dinosaurs-thought-they-had-time-too-over-12000-students-strike-brussels |website=Common Dreams |accessdate=20 January 2019}}</ref> In 2019 The organization [[Extinction Rebellion]] organized massive protests demanding "tell the truth about climate change, reduce carbon emissions to zero by 2025, and create a citizens' assembly to oversee progress", including blocking roads. Many were arrested.<ref>{{cite news |title=Extinction Rebellion: Climate protesters block roads |url=https://www.bbc.com/news/uk-england-london-47935416 |accessdate=16 April 2019 |agency=BBC |date=16 April 2019}}</ref> In many cases, activism brings positive results.<ref>{{cite news |last1=Ruiz |first1=Irene Banos |title=Climate Action: Can We Change the Climate From the Grassroots Up? |url=https://www.ecowatch.com/climate-action-grassroots-2638915946.html |accessdate=23 June 2019 |agency=Deutsche Welle |publisher=Ecowatch |date=June 22, 2019}}</ref>
A major event was the global climate strike in September 2019 organized by [[Fridays For Future]] and [[Earth Strike]].<ref>{{cite news |last1=Zoe Low |first1=Zoe |title=Asia's young climate activists on joining the worldwide campaign for government action on global warming |url=https://www.scmp.com/lifestyle/article/3018803/young-climate-change-activists-asia-pacific-pressuring-governments-take |accessdate=5 August 2019 |agency=South China Morning Post |date=18 July 2019}}</ref> The target was to influence the climate action summit organized by the [[UN]] on September 23.<ref>{{cite news |last1=Korte |first1=Kate |title=Elizabeth May holds nonpartisan town hall at UVic for constituents |url=https://www.martlet.ca/elizabeth-may-holds-nonpartisan-town-hall-at-uvic-for-constituents/ |accessdate=2 August 2019 |agency=Martlet Publishing Society |date=July 10, 2019}}</ref> According to the organizers four million people participated in the strike on September 20.<ref>{{cite news |last1=Conley |first1=Julia |title=4 Million Attend Biggest Climate Protest in History, Organizers Declare 'We're Not Through' |url=https://www.ecowatch.com/global-climate-strike-2640528670.html |accessdate=23 September 2019 |agency=Ecowatch |date=23 September 2019}}</ref>
==See also==
{{Columns-list|colwidth=30em|
*[[4 Degrees and Beyond International Climate Conference]]
*[[Alternative fuel vehicle]]
*[[Black carbon]]
*[[Carbon diet]]
*[[Climate bond]]
*[[Climate change denial]]
*[[Climate Clock]]
*[[Contraction and Convergence]]
*[[Ecological resilience]]
*[[Emissions reduction]] efforts
*[[Environmental impact of the coal industry]]
*[[Green computing]]
*[[Greenhouse gas removal]]
*[[Hell and High Water (book)|''Hell and High Water'']]
*[[Individual action on climate change]]
*[[Iron fertilization]]
*[[List of climate change initiatives]]
*[[List of energy storage projects]]
*[[Lofoten Declaration]]
*[[Low-carbon diet]]
*[[Low-carbon economy]]
*[[Mitigation of peak oil]]
*[[Resistance (ecology)]]
*[[Stratospheric aerosol injection (climate engineering)]]
*[[Vulnerability]]
}}
===By country===
*[[Debate over China's economic responsibilities for climate change mitigation]]
*[[European Climate Change Programme]]
*[[Mitigation of global warming in Australia]]
==Notes==
{{Reflist}}
==References==
*{{citation
|ref=CITEREFClarkeothers2007
|author=Clarke, L.
|date=July 2007
|title=Scenarios of Greenhouse Gas Emissions and Atmospheric Concentrations. Sub-report 2.1A of Synthesis and Assessment Product 2.1 by the U.S. Climate Change Science Program and the Subcommittee on Global Change Research
|publisher=Department of Energy, Office of Biological & Environmental Research
|location=Washington, DC
|url=http://library.globalchange.gov/products/assessments/2004-2009-synthesis-and-assessment-products/sap-2-1a-scenarios-of-greenhouse-gas-emissions-and-atmospheric-concentrations
|display-authors=etal}}
*{{citation
|title=Impact of Japan Earthquake on Views about nuclear energy. Findings from a Global Snap Poll in 47 countries by WIN-Gallup International (21 March – 10 April 2011)
|author=Gallup International
|url=http://www.nrc.co.jp/report/pdf/110420_2.pdf
|date=19 April 2011
|access-date=20 February 2013
|archive-url=https://web.archive.org/web/20160303204820/http://www.nrc.co.jp/report/pdf/110420_2.pdf
|archive-date=3 March 2016
|url-status=dead
|df=dmy-all
}}
*{{Cite report |ref={{harvid|Global Carbon Budget|2019}}
|title=Global Carbon Budget 2019
|last1 = Friedlingstein |first1=Pierre
|last2 = Jones |first2=Matthew W.
|last3 = O'Sullivan |first3=Michael
|last4 = Andrew |first4=Robbie M.
|last5=Hauck|first5=Judith
|last6=Peters|first6=Glen P.
|last7=Peters|first7=Wouter
|last8=Pongratz|first8=Julia
|last9=Sitch|first9=Stephen
|last10=Quéré|first10=Corinne Le
|last11=Bakker|first11=Dorothee C. E.
|date=2019
|journal=Earth System Science Data
|url=https://www.icos-cp.eu/global-carbon-budget-2019}}
*{{cite report|ref={{harvid|IEA ETP Buildings|2017}}
|title=Energy Technology Perspectives (Buildings Scenario)
|date=2017
|publisher=[[International Energy Agency]]
|url=https://iea.blob.core.windows.net/assets/c1199e97-6fe4-46c8-a8d8-e710b623db79/ETP2017scenariodata.zip}}
*{{cite report|ref={{harvid|Global Energy & CO2 Status Report|2019}}
|title=Global Energy and {{CO2}} Status Report
|date=2019
|publisher=[[International Energy Agency]]
|url=https://www.iea.org/reports/global-energy-co2-status-report-2019}}
*{{Citation
|year= 2007
|author= IPCC AR4 WG1
|author-link= IPCC
|title= Climate Change 2007: The Physical Science Basis
|series= Contribution of Working Group I to the [[IPCC Fourth Assessment Report|Fourth Assessment Report]] of the Intergovernmental Panel on Climate Change
|editor= Solomon, S. |editor2=Qin, D. |editor3=Manning, M. |editor4=Chen, Z. |editor5=Marquis, M. |editor6=Averyt, K.B. |editor7=Tignor, M. |editor8=Miller, H.L.
|publisher= Cambridge University Press
|url= http://www.ipcc.ch/publications_and_data/ar4/wg1/en/contents.html
|isbn= 978-0-521-88009-1
}} (pb: {{ISBNT|978-0-521-70596-7}}).
*{{Citation
|year= 2007
|author= IPCC AR4 WG3
|author-link= IPCC
|title= Climate Change 2007: Mitigation of Climate Change
|series= Contribution of Working Group III (WG3) to the [[IPCC Fourth Assessment Report|Fourth Assessment Report]] of the Intergovernmental Panel on Climate Change (IPCC)
|editor= Metz, B. |editor2=Davidson, O.R. |editor3=Bosch, P.R. |editor4=Dave, R. |editor5=Meyer, L.A.
|publisher= Cambridge University Press
|url= http://www.ipcc.ch/publications_and_data/ar4/wg3/en/contents.html
|isbn= 978-0-521-88011-4
}} (pb: {{ISBNT|978-0-521-70598-1}}).
*{{Citation
|year= 2007
|author= IPCC AR4 syr
|author-link= IPCC
|title= Climate Change 2007: Synthesis Report
|series= Contribution of Working Groups I, II and III to the [[IPCC Fourth Assessment Report|Fourth Assessment Report]] of the Intergovernmental Panel on Climate Change
|editor= Core Writing Team |editor2=Pachauri, R.K |editor3=Reisinger, A.
|publisher= IPCC
|location=[[Geneva]], Switzerland
|url= http://www.ipcc.ch/publications_and_data/ar4/syr/en/contents.html
|isbn= 978-92-9169-122-7
}}.
*{{citation
|year=2014
|author=IPCC AR5 WG2 A
|ref={{harvid|IPCC AR5 WG2 A|2014}}
|editor=Field, C.B.
|title=Climate Change 2014: Impacts, Adaptation, and Vulnerability. Part A: Global and Sectoral Aspects (GSA). Contribution of Working Group II (WG2) to the Fifth Assessment Report (AR5) of the Intergovernmental Panel on Climate Change (IPCC)
|url=http://www.ipcc.ch/report/ar5/wg2/
|publisher=Cambridge University Press
|display-editors=etal
|url-status=bot: unknown
|archiveurl=https://web.archive.org/web/20140416051047/http://www.ipcc.ch/report/ar5/wg2/
|archivedate=16 April 2014
}}
* {{Cite book |ref= {{harvid|IPCC AR5 WG3|2014}}
|author = IPCC |author-link = IPCC
|year= 2014
|title= Climate Change 2014: Mitigation of Climate Change
|series= Contribution of Working Group III to the [[IPCC Fifth Assessment Report|Fifth Assessment Report]] of the Intergovernmental Panel on Climate Change
|display-editors= 3
|editor-first1= O. |editor-last1= Edenhofer
|editor-first2= R. |editor-last2= Pichs-Madruga
|editor-first3= Y. |editor-last3= Sokona
|editor-first4= E. |editor-last4= Farahani
|editor-first5= S. |editor-last5= Kadner
|editor-first6= K. |editor-last6= Seyboth
|editor-first7= A. |editor-last7= Adler
|editor-first8= I. |editor-last8= Baum
|editor-first9= S. |editor-last9= Brunner
|editor-first10= P. |editor-last10= Eickemeier
|editor-first11= B. |editor-last11= Kriemann
|editor-first12= J. |editor-last12= Savolainen
|editor-first13= S. |editor-last13= Schlömer
|editor-first14= C. |editor-last14= von Stechow
|editor-first15= T. |editor-last15= Zwickel
|editor-first16= J.C. |editor-last16= Minx
|publisher= Cambridge University Press
|place= Cambridge, United Kingdom and New York, NY, USA
|isbn= 978-1-107-05821-7
}} (pb: {{ISBNT|978-1-107-65481-5}}).
** {{Cite book |ref= {{harvid|IPCC AR5 WG3 Technical Summary|2014}}
|chapter= Technical Summary
|chapter-url= https://archive.ipcc.ch/pdf/assessment-report/ar5/wg3/ipcc_wg3_ar5_technical-summary.pdf
|year= 2014
|display-authors= 4
|first1= O. |last1= Edenhofer
|first2= R. |last2= Pichs-Madruga
|first3= Y. |last3= Sokona
|first4= S. |last4= Kadner
|first5= J. C. |last5= Minx
|first6= S. |last6= Brunner
|first7= S. |last7= Agrawala
|first8= G. |last8= Baiocchi
|first9= I. A. |last9= Bashmakov <!-- And 54 others. -->
|title= {{Harvnb|IPCC AR5 WG3|2014}}
}}
*{{Cite book |ref= {{harvid|IPCC SR15|2018}} <!-- ipcc:20200312 -->
|author= IPCC |author-link= IPCC
|year= 2018
|title= Global Warming of 1.5°C. An IPCC Special Report on the impacts of global warming of 1.5°C above pre-industrial levels and related global greenhouse gas emission pathways, in the context of strengthening the global response to the threat of climate change, sustainable development, and efforts to eradicate poverty
|display-editors= 4
|editor-first1= V. |editor-last1= Masson-Delmotte
|editor-first2= P. |editor-last2= Zhai
|editor-first3= H.-O. |editor-last3= Pörtner
|editor-first4= D. |editor-last4= Roberts
|editor-first5= J. |editor-last5= Skea
|editor-first6= P. R. |editor-last6= Shukla
|editor-first7= A. |editor-last7= Pirani
|editor-first8= W. |editor-last8= Moufouma-Okia
|editor-first9= C. |editor-last9= Péan
|editor-first10= R. |editor-last10= Pidcock
|editor-first11= S. |editor-last11= Connors
|editor-first12= J. B. R. |editor-last12= Matthews
|editor-first13= Y. |editor-last13= Chen
|editor-first14= X. |editor-last14= Zhou
|editor-first15= M. I. |editor-last15= Gomis
|editor-first16= E. |editor-last16= Lonnoy
|editor-first17= T. |editor-last17= Maycock
|editor-first18= M. |editor-last18= Tignor
|editor-first19= T. |editor-last19= Waterfeld
|publisher= Intergovernmental Panel on Climate Change
|isbn= <!-- not issued? -->
|url= https://www.ipcc.ch/site/assets/uploads/sites/2/2019/06/SR15_Full_Report_High_Res.pdf
}} https://www.ipcc.ch/sr15/.
<!-- ## -->
**{{Cite book |ref= {{harvid|IPCC SR15 Ch2|2018}} <!-- ipcc:20200312 -->
|year= 2018
|chapter= Chapter 2: Mitigation Pathways Compatible with 1.5°C in the Context of Sustainable Development
|chapter-url= https://www.ipcc.ch/site/assets/uploads/sites/2/2019/05/SR15_Chapter2_High_Res.pdf
|display-authors= 4
|first1= J. |last1= Rogelj
|first2= D. |last2= Shindell
|first3= K. |last3= Jiang
|first4= S. |last4= Fifta
|first5= P. |last5= Forster
|first6= V. |last6= Ginzburg
|first7= C. |last7= Handa
|first8= H. |last8= Kheshgi
|first9= S. |last9= Kobayashi
|first10= E. |last10= Kriegler
|first11= L. |last11= Mundaca
|first12= R. |last12= Séférian
|first13= M. V. |last13= Vilariño
|title= {{Harvnb|IPCC SR15|2018}}
|pages= 93–174
}}
**{{Cite book |ref= {{harvid|IPCC SR15 Summary for Policymakers|2018}} <!-- ipcc:20200312 -->
|author= IPCC |author-link= IPCC
|year= 2018
|chapter= Summary for Policymakers
|chapter-url= https://www.ipcc.ch/site/assets/uploads/sites/2/2019/05/SR15_SPM_version_report_HR.pdf
|title= {{Harvnb|IPCC SR15|2018}}
|pages= 3–24
}}
<!-- ## -->
**{{Cite book |ref= {{harvid|IPCC SR15 Technical Summary|2018}} <!-- ipcc:20200312 -->
|year= 2018
|chapter= Technical Summary
|chapter-url= https://www.ipcc.ch/site/assets/uploads/sites/2/2019/05/SR15_TS_High_Res.pdf
|display-authors= 4
|first1= M. R. |last1= Allen
|first2= H. |last2= de Coninck
|first3= O. P. |last3= Dube
|first4= O. |last4= Hoegh-Guldberg
|first5= D. |last5= Jacob
|first6= K. |last6= Jiang
|first7= J. A. |last7= Revi
|first8= J. |last8= Rogelj
<!-- And 66 others. -->
|title= {{Harvnb|IPCC SR15|2018}}
|pages= 27–46
}}
<!-- ## -->
*{{citation
|author= Ipsos
|title= Global Citizen Reaction to the Fukushima Nuclear Plant Disaster (theme: environment / climate) Ipsos Global @dvisor
|date= 23 June 2011
|url= http://www.ipsos-mori.com/Assets/Docs/Polls/ipsos-global-advisor-nuclear-power-june-2011.pdf
|url-status= dead
|archiveurl= https://web.archive.org/web/20141224033030/https://www.ipsos-mori.com/Assets/Docs/Polls/ipsos-global-advisor-nuclear-power-june-2011.pdf
|archivedate= 24 December 2014
}}. Survey website: [https://web.archive.org/web/20160403234041/https://www.ipsos-mori.com/researchpublications/researcharchive/2817/strong-global-opposition-towards-nuclear-power.aspx Ipsos MORI: Poll: Strong global opposition towards nuclear power]
*{{cite report |ref=harv
| last1 = Olivier |first1 = J.G.J.
| last2 = Peters |first2 = J.A.H.W.
| year = 2020
| title = Trends in global {{CO2}} and total greenhouse gas emissions (2019)
| publisher = PBL Netherlands Environmental Assessment Agency
| url = https://www.pbl.nl/sites/default/files/downloads/pbl-2020-trends-in-global-co2-and-total-greenhouse-gas-emissions-2019-report_4068.pdf
| place = The Hague
}}
*{{Citation|ref={{harvid|Pellow et al.|2015}}
|last1=Pellow|first1=Matthew A.
|last2=Emmott|first2=Christopher J.M.
|last3=Barnhart|first3=Charles J.
|last4=Benson|first4=Sally M.
|year=2015
|title=Hydrogen or batteries for grid storage? A net energy analysis
|publisher=Royal Society of Chemistry
|url=https://pubs.rsc.org/en/content/articlehtml/2015/ee/c4ee04041d
}}
*{{Citation
|last1 = Sampedro |first=Jon
|last2 = Smith |first2=Steven J.
|last3 = Arto |first3=Iñaki
|last4 = González-Eguino|first4=Mikel
|last5=Markandya|first5=Anil
|last6=Mulvaney|first6=Kathleen M.
|last7=Pizarro-Irizar|first7=Cristina
|last8=Van Dingenen|first8=Rita
|date = 2020
|title=Health co-benefits and mitigation costs as per the Paris Agreement under different technological pathways for energy supply
|url=http://www.sciencedirect.com/science/article/pii/S016041201933911X
|journal=Environment International
|volume=136|pages=105513|doi=10.1016/j.envint.2020.105513|pmid=32006762
|issn=0160-4120|doi-access=free}}
*{{cite journal|ref={{harvid|Schmidt|Melchior|Hawkes|Staffell|2019}}
|last1=Schmidt|first1=Oliver
|last2=Melchior|first2=Sylvain
|last3=Hawkes|first3=Adam
|last4=Staffell|first4=Iain
|date=16 January 2019
|title=Projecting the Future Levelized Cost ofElectricity Storage Technologies
|url=https://www.cell.com/action/showPdf?pii=S2542-4351%2818%2930583-X
|journal=Joule
|volume=44
|issue=3
|pages=81–100
|doi=10.1016/j.joule.2018.12.008
|access-date=5 April 2020|doi-access=free
}}
*{{citation
|title=Geoengineering the climate: science, governance and uncertainty
|author=UK Royal Society
|url=http://royalsociety.org/uploadedFiles/Royal_Society_Content/policy/publications/2009/8693.pdf
|publisher=UK Royal Society
|location=London
|date=September 2009
|isbn=978-0-85403-773-5
}}, RS Policy document 10/09. [http://royalsociety.org/policy/publications/2009/geoengineering-climate/ Report website.]
*{{citation
|author=US NRC
|year=2011
|title=Climate Stabilization Targets: Emissions, Concentrations, and Impacts over Decades to Millennia. A report by the US National Research Council (US NRC)
|url=http://www.nap.edu/catalog.php?record_id=12877
|publisher=National Academies Press
|location=Washington, D.C.
|url-status=dead
|archiveurl=https://web.archive.org/web/20140327000317/http://www.nap.edu/catalog.php?record_id=12877
|archivedate=2014-03-27
}}
*{{citation
|date= November 2012
|author= UNEP
|title= The Emissions Gap Report 2012
|publisher= United Nations Environment Programme (UNEP)
|location= Nairobi, Kenya
|url= http://www.unep.org/pdf/2012gapreport.pdf
|url-status= dead
|archiveurl= http://arquivo.pt/wayback/20160513232928/http://www.unep.org/pdf/2012gapreport.pdf
|archivedate= 2016-05-13
}} Executive summary in [http://arquivo.pt/wayback/20160513232948/http://www.unep.org/publications/ebooks/emissionsgap2012/ other languages]
*{{Include-USGov
|agency=[[US EPA]]
|source={{citation
|author=US EPA
|date=14 June 2012
|title=Glossary of Climate Change Terms: Climate Change: US EPA
|publisher=US Environmental Protection Agency (EPA) Climate Change Division
|url=http://www.epa.gov/climatechange/glossary.html
}}
}}
*{{citation
|title=Meeting the 2 degree target. From climate objective to emission reduction measures. PBL publication number 500114012
|date=7 December 2009
|author=van Vuuren, D.P.
|ref=CITEREFvan Vuurenothers2009
|publisher=Netherlands Environmental Assessment Agency (Planbureau voor de Leefomgeving (PBL))
|url=http://www.pbl.nl/sites/default/files/cms/publicaties/500114012.pdf
|display-authors=etal
|url-status=bot: unknown
|archiveurl=https://web.archive.org/web/20131102030225/http://www.pbl.nl/sites/default/files/cms/publicaties/500114012.pdf
|archivedate=2013-11-02
}}. Archived. [http://www.pbl.nl/node/46765 Report website] (archived [https://web.archive.org/web/20140821023807/http://www.pbl.nl/node/46765 21 August 2014]).
*{{cite web|ref={{harvid|Volkswagen AG: Hydrogen or battery|2019}}
|title=Hydrogen or battery? A clear case, until further notice
|date=7 November 2019
|publisher=Volkswagen AG
|url=https://www.volkswagenag.com/en/news/stories/2019/08/hydrogen-or-battery--that-is-the-question.html
}}
*{{cite journal|ref={{harvid|Welder et al.|2019}}
|last1=Welder|first1= Lara
|last2=Stenzel|first2=Peter
|last3=Ebersbach|first3= Natalie
|last4=Markewitz|first4=Peter
|last5=Robinius|first5=Martin
|last6=Emonts|first6=Bernd
|last7=Stolten|first7=Detlef
|date=12 April 2019
|title=Design and evaluation of hydrogen electricity reconversion pathways in national energy systems using spatially and temporally resolved energy system optimization
|url=https://www.sciencedirect.com/science/article/abs/pii/S0360319918338552
|journal=International Journal of Hydrogen Energy
|volume=44
|issue=19
|pages=9594–9607
|doi=10.1016/j.ijhydene.2018.11.194
|access-date=5 April 2020}}
<br />
== Further reading ==
* National Academies of Sciences, Engineering, and Medicine (2019) ''[[doi:10.17226/25259|Negative Emissions Technologies and Reliable Sequestration: A Research Agenda]].''
==External links==
*[https://unfccc.int/#content-mitigation UNFCCC Mitigation]
*[http://www.ipcc.ch/ Intergovernmental Panel on Climate Change] – Includes the Working Group III Report "Mitigation of Climate Change" as part of the Fourth Assessment Report
*[http://www.foreignaffairs.com/articles/65238/jessica-seddon-wallack-and-veerabhadran-ramanathan/the-other-climate-changers Why Black Carbon and Ozone Also Matter], in September/October 2009 [[Foreign Affairs]] with [[Veerabhadran Ramanathan]] and Jessica Seddon Wallack.
*[http://www.theclimateclub.org/about/ The Climate Club]
*[https://web.archive.org/web/20141027232316/http://www.tyndall.ac.uk/radical-emission-reduction-conference-10-11-december-2013-register-here The Radical Emission Reduction Conference]
===Countries and regions===
*EU [https://ec.europa.eu/clima/ Climate Action]
*[https://web.archive.org/web/20051105043801/http://www.seattle.gov/mayor/climate/ U.S. Mayors Climate Protection Agreement] signed by 178 mayors representing nearly 40 million Americans
*UK [https://www.theccc.org.uk/tackling-climate-change/reducing-carbon-emissions/ Committee on Climate Change]
===Academic===
*Rivington M, Matthews KB, Buchan K and Miller D (2005) [http://www.macaulay.ac.uk/LADSS/papers.html?2005 "An integrated assessment approach to investigate options for mitigation and adaptation to climate change at the farm-scale"], NJF Seminar 380, [[Odense]], Denmark, 2005.
*{{cite journal
|last1= Jacobson |first1= M.Z. |last2= Delucchi |first2= M.A. |year= 2009
|title= A Plan to Power 100 Percent of the Planet with Renewables" (originally published as "A Path to Sustainable Energy by 2030")
|journal= Scientific American |volume= 301 |issue= 5 |pages= 58–65
|pmid= 19873905 |doi= 10.1038/scientificamerican1109-58
|bibcode= 2009SciAm.301e..58J}}
*[http://www.scientificamerican.com/article.cfm?id=living-on-a-new-earth Living On a New Earth], [[Scientific American]] April 2010
*[https://web.archive.org/web/20110201100216/http://globalwarmingnewswire.com/ Global Warming Newswire] – published scientific studies on global warming
{{Global warming}}
{{Sustainability}}
{{Portal bar|Global warming|Energy}}
[[Category:Climate change mitigation| ]]
[[Category:Climate change policy]]
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