气候变化的影响归因:来自IPCC AR6 WGⅡ的新认知

Impact attribution of climate change:the new cognition from IPCC AR6 WGⅡ

归因(Attribution)包括气候变化归因(Climate change attribution)、影响归因(Impact attribution)和天气敏感性识别(Identification of weather sensitivity)等三个方面。IPCC第六次评估报告第二工作组报告(AR6 WGⅡ)沿用了第五次评估报告第二工作组报告(AR5 WGⅡ)中关于气候变化影响归因的定义,认为气候变化影响归因评估气候系统变化对观测到的自然、人类或受管理系统变化的贡献程度。IPCC AR6 WGⅡ提出了在影响归因中构建“无气候变化基准期”(no-climate change baseline)的基本研究思路,总结了气候变化对陆地生态系统、海洋生态系统、海岸系统、水系统、食物系统、人类社会影响归因研究的重要进展。相比于AR5 WGⅡ,AR6 WGⅡ更加具体地描述了气候变化对自然、人类或受管理系统的影响程度,部分评估结论的信度也得到了提升,且在气候变化的社会影响方面给出了更多的证据。尽管气候变化影响归因方面取得了一定进展,但AR6 WGⅡ指出仍需要更多高质量的数据、更有效的气候变化影响量化方法、更全面的系统变化机制理解来深化气候变化影响归因研究。

Attribution studies include climate change attribution,impact attribution and identification of weather sensitivity.IPCC Sixth Assessment Report Working GroupⅡ(AR6 WGⅡ)follows the definition of climate change impact attribution in the Fifth Assessment Report Working GroupⅡ(AR5 WGⅡ),and considers that climate change impact attribution assesses the contribution of climate system changes to observed natural,human or managed system changes.IPCC AR6 WGⅡsets up a“no-climate change baseline”in the impact attribution studies,and summarizes most recent achievements on the impact attribution of climate change on terrestrial ecosystems,marine ecosystems,coastal systems,water systems,food systems and human society.Compared with the AR5 WGⅡ,the AR6 WGⅡmore specifically describes the impact of climate change on nature,human or managed systems,improves the reliability of some assessment conclusions,and gives more evidence on the social impact of climate change.Although some progresses have been made in climate change impact attribution,the AR6 WGⅡpoints out that more high-quality data,more effective methods for quantifying climate change impacts and more comprehensive understanding on the mechanisms of systematic change are still needed to deepen the research on climate change impact attribution.