The United States has one of the world's largest oil and gas (O&G) industries, yet the health impacts and inequities from pollutants produced along the O&G lifecycle remain poorly characterized. Here, we model the contribution of major lifecycle stages (upstream, midstream, downstream, and end-use) to air pollution and estimate the associated chronic health outcomes and racial-ethnic disparities across the contiguous US in 2017. We estimate lifecycle annual burdens of 91,000 premature deaths attributable to fine particles (PM2.5), nitrogen dioxide (NO2), and ozone, 10,350 PM2.5-attributable preterm births, 216,000 incidences of NO2-attributable childhood-onset asthma, and 1610 lifetime cancers attributable to hazardous air pollutants (HAPs). Racial-ethnic minorities experience the greatest disparities in exposure and health burdens across almost all lifecycle stages. The greatest absolute disparities occur for Black and Asian populations from PM2.5 and ozone, and the Asian population from NO2 and HAPs. Relative inequities are most extreme from downstream activities, especially in Louisiana and Texas.

The production and use of fossil fuels need to decline rapidly to limit global warming. Although global net-zero scenarios abound, the associated development ramifications for fossil fuel-producing low and lower–middle income countries (LLMICs), as well as adequate international responses, have been underexplored. Here we conceptualize that, depending on country context, three types of development transition follow from declining fossil fuel production and use for LLMIC producers, namely an energy transition, an economic transition and an equitable fossil fuel production transition. We propose a classification of these transitions, arguing that heterogeneity in LLMICs’ fossil fuel production and usage substantially impacts their pathways towards low-carbon development. We illustrate this by discussing different cases of fossil fuel-producing LLMICs, focusing on Mozambique, India, Lao PDR and Angola. We conclude by detailing context-specific international support portfolios to foster low-carbon development in fossil fuel-producing LLMICs, and call for a re-orientation of international support along principles of global solidarity.

The mitigation scenarios database of the Intergovernmental Panel on Climate Change’s Sixth Assessment Report is an important resource for informing policymaking on energy transitions. However, there is a large variety of models, scenario designs, and resulting outputs. Here we analyse the scenarios consistent with limiting warming to 2 °C or below regarding the speed, trajectory, and feasibility of different fossil fuel reduction pathways. In scenarios limiting warming to 1.5 °C with no or limited overshoot, global coal, oil, and natural gas supply (intended for all uses) decline on average by 95%, 62%, and 42%, respectively, from 2020 to 2050, but the long-term role of gas is highly variable. Higher-gas pathways are enabled by higher carbon capture and storage (CCS) and carbon dioxide removal (CDR), but are likely associated with inadequate model representation of regional CO 2 storage capacity and technology adoption, diffusion, and path-dependencies. If CDR is constrained by limits derived from expert consensus, the respective modelled coal, oil, and gas reductions become 99%, 70%, and 84%. Our findings suggest the need to adopt unambiguous near- and long-term reduction benchmarks in coal, oil, and gas production and use alongside other climate mitigation targets.

Abstract Non-technical summary We identify a set of essential recent advances in climate change research with high policy relevance, across natural and social sciences: (1) looming inevitability and implications of overshooting the 1.5°C warming limit, (2) urgent need for a rapid and managed fossil fuel phase-out, (3) challenges for scaling carbon dioxide removal, (4) uncertainties regarding the future contribution of natural carbon sinks, (5) intertwinedness of the crises of biodiversity loss and climate change, (6) compound events, (7) mountain glacier loss, (8) human immobility in the face of climate risks, (9) adaptation justice, and (10) just transitions in food systems. Technical summary The Intergovernmental Panel on Climate Change Assessment Reports provides the scientific foundation for international climate negotiations and constitutes an unmatched resource for researchers. However, the assessment cycles take multiple years. As a contribution to cross- and interdisciplinary understanding of climate change across diverse research communities, we have streamlined an annual process to identify and synthesize significant research advances. We collected input from experts on various fields using an online questionnaire and prioritized a set of 10 key research insights with high policy relevance. This year, we focus on: (1) the looming overshoot of the 1.5°C warming limit, (2) the urgency of fossil fuel phase-out, (3) challenges to scale-up carbon dioxide removal, (4) uncertainties regarding future natural carbon sinks, (5) the need for joint governance of biodiversity loss and climate change, (6) advances in understanding compound events, (7) accelerated mountain glacier loss, (8) human immobility amidst climate risks, (9) adaptation justice, and (10) just transitions in food systems. We present a succinct account of these insights, reflect on their policy implications, and offer an integrated set of policy-relevant messages. This science synthesis and science communication effort is also the basis for a policy report contributing to elevate climate science every year in time for the United Nations Climate Change Conference. Social media summary We highlight recent and policy-relevant advances in climate change research – with input from more than 200 experts.

Abstract The world’s large and growing appetite for meat and other animal products has profound implications for One Health, given its impacts on human health, the environment and animal health and welfare. Accordingly, there is robust evidence that a reduction of animal product consumption is urgently needed in regions where these consumption levels are currently high. A shift away from industrial animal production should be prioritized, given the high levels of animal product consumption this kind of system enables, its relatively high environmental toll, linkages to increasing risks of antimicrobial resistance and zoonoses emergence and harm to animal welfare. Until recently, however, few governments addressed the issue. On the contrary, many governments actively support industrial animal agriculture through subsidies and other measures. Now, motivated by both environmental and public health concerns, policy makers in several countries are adopting regulatory and financial measures to address the overconsumption of animal products. Although these changes are clearly necessary and long overdue, it is crucial that they are planned carefully and inclusively to ensure a just transition. In lower-resourced and food-insecure settings, meat and other animal products can be a vital source of nutrients – particularly during infancy and childhood. In addition, meat supply chains support many livelihoods, and meat is an important part of many people’s social and cultural traditions. This means that policies that curtail common production practices, reduce meat output and raise meat prices could have significant impacts across society. A just transition approach can help ensure that the costs and benefits of the transition are more equitably distributed and protect the most vulnerable stakeholders. By doing so, it can also help increase public support for the transition. The concept of just transitions is well established in the energy sector but is only starting to be recognized in the context of the food system. Governments in the Global North should take the lead in this area, given these countries have very high levels of animal product consumption and more resources available to support a transition. In this Policy Forum, we lay out the case for a just transition in animal agriculture and identify five principles to guide policy makers in promoting a just transition away from systems of industrial meat production and overconsumption. One Health impact statement Drawing on expertise from health, climate, biodiversity and animal welfare policy and science across several regions, this Policy Forum demonstrates how current levels of animal product production and consumption threaten One Health. Although a transition to a healthier, more sustainable and more compassionate food system is clearly needed, such a transition will necessarily involve both costs and benefits for affected stakeholders. Identifying lessons from international and national climate policy, and energy policy in particular, the authors highlight the value of an approach that is holistic and centred on just transition principles to support a transition away from large-scale animal product production and consumption that is in line with the One Health approach, with an emphasis on transitioning away from the consumption and production of industrially-produced meat. This Policy Forum is relevant to policy makers, companies and civil society seeking to promote a shift towards food systems that emphasize public and planetary health.

At present, most global GHG emissions – over 75% – are from fossil fuels. By necessity, reaching net zero emissions therefore requires dramatic reductions in fossil fuel demand and supply. Though fossil fuels have not been explicitly addressed by the UN Framework on Climate Change, a conversation has emerged about possible “supply-side” agreements on fossil fuels and climate change. For example, a number of countries, including Denmark, France, and New Zealand, have started taking measures to phase out their oil and gas production. In the United States, President Joe Biden has put a pause on new oil and gas leasing on federal lands and waters, while Vice President Kamala Harris has previously proposed a “first-ever global negotiation of the cooperative managed decline of fossil fuel production”. This paper aims to contribute to this emerging discussion. The authors present a simple analysis on where fossil fuel extraction has happened historically, and where it will continue to occur and expand if current economic trends continue without new policy interventions. By employing some simple scenario analysis, the authors also demonstrate how the phase-out of fossil fuel production is likely to be inequitable among countries, if not actively and internationally managed.

The United States has supported the development of its oil and gas industry since the early twentieth century. Despite repeated pledges to phase out ‘inefficient’ fossil fuel subsidies, US oil and gas production continues to be subsidized by billions of dollars each year. In this study, we quantify how 16 subsidies and regulatory exemptions individually and altogether affect the economics of US oil and gas production in 2020–2030 under different price and financial risk outlooks. We find that, at 2019 average market prices of oil and gas, the 16 subsidies could increase the average rates of return of yet-to-be-developed oil and gas fields by 55% and 68% over unsubsidized levels, respectively, with over 96% of subsidy value flowing to excess profits under a 10% hurdle rate. At lower 2020 prices, the subsidies could increase the average rates of return of new oil and gas fields by 63% and 78% over unsubsidized levels, respectively, with more than 60% of oil and gas resources being dependent on subsidies to be profitable under a 20% hurdle rate. Under all price scenarios analyzed, the highest-value subsidies include federal tax incentives that have existed since 1916, as well as less recognized forms of support such as cost exemptions related to well cleanup and hazardous waste management. Given that these results depend on our chosen definitions of what constitutes a subsidy and, in some cases, assumptions regarding what the unsubsidized practices should be, we also present results for selected subsets of subsidies. By showing which subsidies have the greatest effects in different producing regions of the country, our findings can help policymakers chart a schedule of targeted subsidy repeals and regulatory reforms that can contribute to reducing carbon dioxide emissions and achieving other sustainable development goals. Our results can also help inform how different choices about economic recovery measures in response to the COVID-19 pandemic can shape the US oil and gas industry in the years to come.