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Abstract 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 CO2 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 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.

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.