Editing IPCC:AR6/SRCCL/Chapter-7 (section)

==== 7.4.4.1 GHG fluxes and climate change mitigation ====

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Pathways reflecting current nationally stated mitigation ambitions as submitted under the Paris Agreement would not limit global warming to 1.5°C with no or limited overshoot, but instead result in a global warming of about 3°C by 2100 with warming continuing afterward (IPCC 2018d). Reversing warming after an overshoot of 0.2°C or higher during this century would require deployment of CDR at rates and volumes that might not be achievable given considerable implementation challenges (IPCC 2018d). This gap (Höhne et al. 2017 <sup>[[#fn:r531|531]]</sup> ; Rogelj et al. 2016 <sup>[[#fn:r532|532]]</sup> ) creates a significant risk of global warming impacting on land degradation, desertification, and food security (IPCC 2018d <sup>[[#fn:r533|533]]</sup> ) (Section 7.2). Action can be taken by 2030 adopting already known cost-effective technology (United Nations Environment Programme 2017 <sup>[[#fn:r534|534]]</sup> ), improving the finance, capacity building, and technology transfer mechanisms of the United Nations Framework Convention on Climate Change (UNFCCC), improving food security (listed by 73 nations in their nationally determined contributions (NDCs)) and nutritional security (listed by 25 nations) (Richards et al. 2015 <sup>[[#fn:r535|535]]</sup> ). UNFCCC Decision 1. CP21 reaffirmed the UNFCCC target that ‘developed country parties provide USD 100 billion annually by 2020 for climate action in developing countries’ (Rajamani 2011 <sup>[[#fn:r536|536]]</sup> ) and a new collective quantified goal above this floor is to be set, taking into account the needs and priorities of developing countries (Fridahl and Linnér 2016 <sup>[[#fn:r537|537]]</sup> ).

Mitigation policy instruments to address this shortfall include financing mechanisms, carbon pricing, cap and trade or emissions trading, and technology transfer. While climate change is a global commons problem containing free-riding issues cost-effective international policies that ensure that countries get the most environmental benefit out of mitigation investments promote an international climate policy regime (Nordhaus 1999 <sup>[[#fn:r538|538]]</sup> ; Aldy and Stavins 2012 <sup>[[#fn:r539|539]]</sup> ). Carbon pricing instruments may provide an entry point for inclusion of appropriate agricultural carbon instruments. Models of cost-efficient distribution of mitigation across regions and sectors typically employ a global uniform carbon price, but such treatment in the agricultural sector may impact on food security (Section 7.4.4.4).

One policy initiative to advance climate mitigation policy coherence in this section is the phase out of subsidies for fossil fuel production (see also Section 7.4.8). The G20 agreed in 2009, and the G7 agreed in 2016, to phase out these subsidies by 2025. Subsidies include lower tax rates or exemptions and rebates of taxes on fuels used by particular consumers (diesel fuel used by farming, fishing, etc.), types of fuel, or how fuels are used. The OECD estimates the overall value of these subsides to be 160–200 billion USD annually between 2010 and 2014 (OECD 2015 <sup>[[#fn:r540|540]]</sup> ). The phase-out of fossil fuel subsidies has important economic, environmental and social benefits. Coady et al. (2017) <sup>[[#fn:r541|541]]</sup> estimate the economic and environmental benefits of reforming fossil fuel subsidies could be valued worldwide at 4.9 trillion USD in 2013, and 5.3 trillion USD in 2015. Eliminating subsidies could have reduced emissions by 21%, raised 4% of global GDP as revenue (in 2013), and improved social welfare (Coady et al. 2017 <sup>[[#fn:r542|542]]</sup> ).

Legal instruments addressing perceived deficiencies in climate change mitigation include human rights and liability. Developments in attribution science are improving the ability to detect human influence on extreme weather. Marjanac et al. (2017) <sup>[[#fn:r543|543]]</sup> argue that this broadens the legal duty of government, business and others to manage foreseeable harms, and may lead to more climate change litigation (Marjanac et al. 2017) <sup>[[#fn:r544|544]]</sup> . Peel and Osofsky (2017) <sup>[[#fn:r545|545]]</sup> argue that courts are becoming increasingly receptive to employ human rights claims in climate change lawsuits (Peel and Osofsky 2017 <sup>[[#fn:r546|546]]</sup> ); citizen suits in domestic courts are not a universal phenomenon and, even if unsuccessful, Estrin (2016) <sup>[[#fn:r547|547]]</sup> concludes they are important in underlining the high level of public concern.

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