Climate Tipping Points: Uncertainty-aware quantification of Earth system tipping potential from observations and models and assessment of associated climatic, ecological, and socioeconomic impacts

在持续的人为强迫下，地球系统发生大规模倾覆事件的可能性仍然不确定。鉴于这类事件可能具有不可逆转性，并可能对气候、生态系统和社会造成灾难性的全球后果，预防原则要求对潜在机制、复合或连锁影响以及相关风险进行彻底调查。气候提示将极大地促进对可能的地球系统倾倒元素(TES)的过程理解。它将提供一个方法学框架，用于从古气候、观测和模型数据中确定潜在的TES并加以限制，用于从观测和模型中确定未知的倾倒潜力，以及用于量化气候和生态系统的复原力及其变化，包括对即将发生的过渡的预警。地球系统模型(ESM)是预测大规模倾覆事件风险的主要工具，而气候提示将极大地改善它们对建议的TES的表示。这将有助于确定稳定的地球系统的安全工作空间，方法是通过经验数据和ESM，根据关键的地球系统TES的临界阈值和速率、滞后和超调潜力，并考虑到相关的不确定性，来确定这些TES的特征。作为一项独特的气候服务，气候提示将根据综合环境监测系统中倾倒事件的故事情节，为大规模倾倒事件提供全球高分辨率、经偏差校正的气候场。将在全球范围内评估对气候、生态系统、生物多样性、农业、社会和经济的相关影响，并将其与《巴黎协定》和欧盟《2030年生物多样性战略》联系起来。气候提示将为意识到TIP的风险评估以及适应和缓解战略提供全面和准确的知识基础。结果将向科学界、公众和目标受众传播，包括国际地球科学计划和政府间气候变化专门委员会。

The likelihood of large-scale Earth system tipping events under ongoing anthropogenic forcing remains uncertain. In view of the possible irreversibility associated with such events and the potentially catastrophic global consequences on climate, ecosystems, and society, the precautionary principle demands thorough investigation of the underlying mechanisms, compound or cascading impacts, and associated risks. ClimTip will substantially advance the process understanding of possible Earth system Tipping Elements (TEs). It will provide the methodological framework for characterising and constraining potential TEs from paleoclimate, observational and model data, for identifying unknown tipping potential from observations and models, and for quantifying resilience and changes thereof in climate and ecosystems, including early-warning of forthcoming transitions. Earth system models (ESMs) are the primary tool for projecting the risk of large-scale tipping events and ClimTip will substantially improve their representation of suggested TEs. This will enable the identification of safe operating spaces for a stable Earth system by characterising key Earth system TEs in terms of their critical thresholds and rates, hysteresis and overshoot potential via empirical data and ESMs, taking into account the associated uncertainties. As a unique climate service, ClimTip will provide global high-resolution bias-corrected climate fields for large-scale tipping events based on storylines of tipping in comprehensive ESMs. The associated impacts on climate, ecosystems, biodiversity, agriculture, society and economy will be assessed globally and put in relation with the Paris Agreement and the EU Biodiversity Strategy 2030. ClimTip will deliver a comprehensive and precise knowledge basis for tipping-aware risk assessment and adaptation and mitigation strategies. Results will be disseminated to the scientific community, general public, and targeted audiences including IPBES and IPCC.