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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. An analysis of the IPCC AR6 scenarios database explores how quickly coal, oil, and gas production and use should be reduced in line with net-zero goals, and points to the need to adopt phase-out benchmarks alongside other climate mitigation targets. [ABSTRACT FROM AUTHOR]

To reach the mitigation goals of the Paris Agreement, many countries will have to phase out their coal power plants prematurely, i.e., before the end of their normal lifetimes, which will lead quite possibly to significant stranded assets. This could present a major challenge, particularly for many of the rapidly developing countries whose electricity demand is growing and which are currently expanding their coal fleets. Recent research shows that countries with aging power plants and decreasing coal consumption are more inclined to phase out coal, but little is known about where, why, and how coal power plants are being prematurely retired. In the context of the hybrid Paris Agreement, attention is increasingly shifting to domestic mitigation capacities and, alongside this--given the vested interests involved in different sectors--to state capacity to implement the transformations required to achieve deep decarbonization. In this article, we aim to study those capacities in the context of coal phaseout. We use a recent and comprehensive global dataset on coal power plants and employ a mixed-methods research design to (a) identify general emerging patterns with respect to premature coal fleet retirement, and (b) derive stylized types of political strategies to prematurely retire coal power plants. We find state capacity to be a robust predictor of general and premature coal retirement, and we identify three main strategies that countries have used to date to prematurely retire coal: (a) rein-in using top-down regulatory enforcement of environmental, climate, or other regulations that affect the operating licenses of coal plants; (b) buy-out or provision of compensation to companies and regions to appease vested interests; and (c) crowd out where accelerating market and price dynamics in the power sector crowd out coal. We propose that future research should explore more systematically the kinds of strategy that might be most promising in the regions and countries needing to rapidly phase out coal, taking into account their political structures, and also the implications that such strategies might have for global mitigation efforts. [ABSTRACT FROM AUTHOR]

The implementation of ambitious climate policies consistent with the goals of the Paris Agreement is fundamentally influenced by political dynamics. Yet, thus far, climate mitigation pathways developed by integrated assessment models (IAMs) have devoted limited attention to the political drivers of climate policymaking. Bringing together insights from the political science and socio-technical transitions literature, we summarize evidence on how emissions lock-in, capacity, and public opinion can shape climate policy ambition. We employ a set of indicators to describe how these three factors vary across countries and regions, highlighting context-specific challenges and enablers of climate policy ambition. We outline existing studies that incorporate political factors in IAMs and propose a framework to employ empirical data to build climate mitigation scenarios that incorporate political dynamics. Our findings show that there is substantial heterogeneity in key political drivers of climate policy ambition within IAM regions, calling for a more disaggregated regional grouping within models. Importantly, we highlight that the political challenges and enablers of climate policy ambition considerably vary across regions, suggesting that future modeling efforts incorporating political dynamics can significantly increase the realism of IAM scenarios. [ABSTRACT FROM AUTHOR]

The Paris Agreement, adopted in 2015, paved the way for a new hybrid global climate governance architecture with both bottom-up and top-down elements. While governments can choose individual climate goals and actions, a global stocktake and a ratcheting-up mechanism have been put in place with the overall aim to ensure that collective efforts will prevent increasing adverse impacts of climate change. Integrated assessment models show that current combined climate commitments and policies of national governments fall short of keeping global warming to 1.5 °C or 2 °C above preindustrial levels. Although major greenhouse gas emitters, such as China, the European Union, India, the United States under the Biden administration, and several other countries, have made new pledges to take more ambitious climate action, it is highly uncertain where global climate policy is heading. Scenarios in line with long-term temperature targets typically assume a simplistic and hardly realistic level of harmonization of climate policies across countries. Against this backdrop, this article develops four archetypes for the further evolution of the global climate governance architecture and matches them with existing sets of scenarios developed by integrated assessment models. By these means, the article identifies knowledge gaps in the current scenario literature and discusses possible research avenues to explore the pre-conditions for successful coordination of national policies towards achieving the long-term target stipulated in the Paris Agreement. [ABSTRACT FROM AUTHOR]

A large-scale transformation of the energy system, which climate mitigation entails, is a global and highly politicized problem. This thematic issue brings together scholars who work with Integrated Assessment Models (IAMs)--which are used for Intergovernmental Panel on Climate Change (IPCC) reports and other key analyses of future climate trajectories--and social scientists working on climate and energy issues to highlight how the two strands of research could benefit from combining insights across different disciplines and methods. One of the key messages across almost all contributions is that the more technical perspectives could benefit from adjusting their assumptions to reflect the patterns observed in quantitative and qualitative social science. Combining different disciplines is methodologically challenging but promising to ensure that the mitigation strategies developed are considered technically and politically feasible, as well as just. [ABSTRACT FROM AUTHOR]