Prudent risk management requires consideration of bad-to-worst-case scenarios. Yet, for climate change, such potential futures are poorly understood. Could anthropogenic climate change result in worldwide societal collapse or even eventual human extinction? At present, this is a dangerously underexplored topic. Yet there are ample reasons to suspect that climate change could result in a global catastrophe. Analyzing the mechanisms for these extreme consequences could help galvanize action, improve resilience, and inform policy, including emergency responses. We outline current knowledge about the likelihood of extreme climate change, discuss why understanding bad-to-worst cases is vital, articulate reasons for concern about catastrophic outcomes, define key terms, and put forward a research agenda. The proposed agenda covers four main questions: 1) What is the potential for climate change to drive mass extinction events? 2) What are the mechanisms that could result in human mass mortality and morbidity? 3) What are human societies' vulnerabilities to climate-triggered risk cascades, such as from conflict, political instability, and systemic financial risk? 4) How can these multiple strands of evidence—together with other global dangers—be usefully synthesized into an “integrated catastrophe assessment”? It is time for the scientific community to grapple with the challenge of better understanding catastrophic climate change.

中文翻译：

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气候结局：探索灾难性的气候变化情景

审慎的风险管理需要考虑最坏的情况。然而，对于气候变化，这种潜在的未来知之甚少。人为气候变化会导致全球社会崩溃甚至最终人类灭绝吗？目前，这是一个危险的探索不足的话题。然而，有充分的理由怀疑气候变化可能导致全球灾难。分析这些极端后果的机制可能有助于激发行动、提高弹性并为政策提供信息，包括应急响应。我们概述了当前关于极端气候变化可能性的知识，讨论了为什么理解从最坏到最坏的情况至关重要，阐明了对灾难性后果的担忧的原因，定义了关键术语，并提出了研究议程。拟议的议程包括四个主要问题：1) 气候变化导致大规模灭绝事件的可能性有多大？2) 导致人类大量死亡和发病的机制是什么？3) 人类社会在冲突、政治不稳定和系统性金融风险等气候引发的风险级联中的脆弱性是什么？4) 如何将这些多重证据连同其他全球性危险有效地综合成“综合灾难评估”？现在是科学界应对更好地了解灾难性气候变化的挑战的时候了。政治不稳定和系统性金融风险？4) 如何将这些多重证据连同其他全球性危险有效地综合成“综合灾难评估”？现在是科学界应对更好地了解灾难性气候变化的挑战的时候了。政治不稳定和系统性金融风险？4) 如何将这些多重证据连同其他全球性危险有效地综合成“综合灾难评估”？现在是科学界应对更好地了解灾难性气候变化的挑战的时候了。