Equity issues have long been debated within international climate politics, focused on fairly distributing reductions in territorial emissions and fossil fuel consumption. There is a growing recognition among scholars and policymakers that curbing fossil fuel supply (as well as demand) can be a valuable part of the climate policy toolbox; this raises the question of where and how the tool should be applied. This paper explores how to equitably manage the social dimensions of a rapid transition away from fossil fuel extraction. Fossil fuel extraction leads to benefits for some people (such as extraction workers) and harms for others (such as pollution-affected communities). A transition must respect and uphold the rights of both groups, while also staying within climate limits, as climate impacts will fall most heavily on the world's poor. This paper begins by reviewing how extraction affects economies and communities and the different transitional challenges they face. Based on that review, it then examines three common equity approacheseconomic efficiency, meeting development needs, and effort-sharing. Drawing lessons from the strengths and weaknesses of these approaches, the paper proposes five principles as a basis for equitably curbing fossil fuel extraction within climate limits:(1) Phase out global extraction at pace consistent with limiting warming to 1.5°C;(2) Enable a just transition for workers and communities;(3) Curb extraction consistent with environmental justice; (4) Reduce extraction fastest where doing so will have the least social costs;(5) Share transition costs fairly, according to ability to bear those costs. Key policy insights:. Fossil fuel extraction is unlikely to be a viable path to development because the Paris Agreement goals require most fossil fuel use to be ended within a generation; . Extraction should be phased out fastest in diversified, wealthier economies that can better absorb the transitional impacts; . Governments of extracting countries should enact ambitious industrial policy to diversify their economies, alongside economic and employment policies to enable a just transition; . The costs of a just transition should be borne by those most able to bear it: poorer countries can reasonably demand financial support.

Carbon emissions-and hence fossil fuel combustion-must decline rapidly if warming is to be held below 1.5 or 2°C. Yet fossil fuels are so deeply entrenched in the broader economy that a rapid transition poses the challenge of significant transitional disruption. Fossil fuels must be phased out even as access to energy services for basic needs and for economic development expands, particularly in developing countries. Nations, communities, and workers that are economically dependent on fossil fuel extraction will need to find a new foundation for livelihoods and revenue. These challenges are surmountable. In principle, societies could undertake a decarbonization transition in which they anticipate the transitional disruption, and cooperate and contribute fairly to minimize and alleviate it. Indeed, if societies do not work to avoid that disruption, a decarbonization transition may not be possible at all. Too many people may conclude they will suffer undue hardship, and thus undermine the political consensus required to undertake an ambitious transition. The principles and framework laid out here are offered as a contribution to understanding the nature of the potential impacts of a transition, principles for equitably sharing the costs of avoiding them, and guidance for prioritizing which fossil resources can still be extracted.

The Paris climate goals and the Glasgow Climate Pact require anthropogenic carbon dioxide (CO2) emissions to decline to net zero by mid-century. This will require overcoming carbon lock-in throughout the energy system. Previous studies have focused on ‘committed emissions’ from capital investments in energy-consuming infrastructure, or potential (committed and uncommitted) emissions from fossil fuel reserves. Here we make the first bottom-up assessment of committed CO2 emissions from fossil fuel-producing infrastructure, defined as existing and under-construction oil and gas fields and coal mines. We use a commercial model of the world’s 25 000 oil and gas fields and build a new dataset on coal mines in the nine largest coal-producing countries. Our central estimate of committed emissions is 936 Gt CO2, comprising 47% from coal, 35% from oil and 18% from gas. We find that staying within a 1.5 °C carbon budget (50% probability) implies leaving almost 40% of ‘developed reserves’ of fossil fuels unextracted. The finding that developed reserves substantially exceed the 1.5 °C carbon budget is robust to a Monte Carlo analysis of reserves data limitations, carbon budget uncertainties and oil prices. This study contributes to growing scholarship on the relevance of fossil fuel supply to climate mitigation. Going beyond recent warnings by the International Energy Agency, our results suggest that staying below 1.5 °C may require governments and companies not only to cease licensing and development of new fields and mines, but also to prematurely decommission a significant portion of those already developed.

In IPCC pathways limiting warming to 1.5˚C, global coal power generation declines rapidly, due to its emissions intensity and substitutability. However, at the national level, we nd that in countries highly dependent on coal generation -China, India and South Africa -this translates to a decline twice as fast as achieved historically for any power technology in any country, relative to system size. To explore a more societally feasible balance of mitigation, we constrain an integrated assessment model to the Powering Past Coal Alliance's differentiated pace of phaseout, by 2030 in OECD/EU and 2050 elsewhere. We nd that limiting warming to 1.5˚C then requires CO2 emissions reductions in the Global North to be roughly 50% faster than if this sociopolitical reality is neglected. This additional mitigation is focused in Europe and the USA, in transport and industry, and implies faster decline in global oil and gas production.