奥地利国际应用系统分析研究所Schleussner Carl-Friedrich团队最新的研究表明人们对气候过冲过度乐观。2024年10月9日出版的《自然》杂志发表了这项成果。

据悉，全球减排的努力仍不足以实现《巴黎协定》的温控目标。这使得系统地探索所谓的过冲路径(在将温度降至更安全的水平之前暂时超过全球变暖的目标限制)，成为科学和政策的优先事项。

研究表明，全球和区域气候变化及其相关风险在过冲后与避免过冲后的世界是不同的。结果显示，与仅稳定的全球变暖(包括海平面上升和冰冻圈变化)相比，实现全球气温下降可以约束长期的气候风险。然而，全球变暖在未来几十年逆转的可能性与当今的适应规划来说可能是有限的。强烈的地球系统反馈可能会削弱温度逆转，引起短期和长期的持续升温。

研究确定了几百亿吨的预防性二氧化碳清除能力的地球物理需求，以对冲和保护高风险的后果。然而，技术、经济和可持续性方面的考虑，可能会限制这种大规模二氧化碳去除部署的实现。因此，研究结果强调，不能确信在当今预期的时间尺度内，过冲后的温度下降的目标是可以实现的，只有快速的短期减排才能有效降低气候风险。

附：英文原文

Title: Overconfidence in climate overshoot

Author: Schleussner, Carl-Friedrich, Ganti, Gaurav, Lejeune, Quentin, Zhu, Biqing, Pfleiderer, Peter, Prtz, Ruben, Ciais, Philippe, Frlicher, Thomas L., Fuss, Sabine, Gasser, Thomas, Gidden, Matthew J., Kropf, Chahan M., Lacroix, Fabrice, Lamboll, Robin, Martyr, Rosanne, Maussion, Fabien, McCaughey, Jamie W., Meinshausen, Malte, Mengel, Matthias, Nicholls, Zebedee, Quilcaille, Yann, Sanderson, Benjamin, Seneviratne, Sonia I., Sillmann, Jana, Smith, Christopher J., Steinert, Norman J., Theokritoff, Emily, Warren, Rachel, Price, Jeff, Rogelj, Joeri

Issue&Volume: 2024-10-09

Abstract: Global emission reduction efforts continue to be insufficient to meet the temperature goal of the Paris Agreement. This makes the systematic exploration of so-called overshoot pathways that temporarily exceed a targeted global warming limit before drawing temperatures back down to safer levels a priority for science and policy. Here we show that global and regional climate change and associated risks after an overshoot are different from a world that avoids it. We find that achieving declining global temperatures can limit long-term climate risks compared with a mere stabilization of global warming, including for sea-level rise and cryosphere changes. However, the possibility that global warming could be reversed many decades into the future might be of limited relevance for adaptation planning today. Temperature reversal could be undercut by strong Earth-system feedbacks resulting in high near-term and continuous long-term warming. To hedge and protect against high-risk outcomes, we identify the geophysical need for a preventive carbon dioxide removal capacity of several hundred gigatonnes. Yet, technical, economic and sustainability considerations may limit the realization of carbon dioxide removal deployment at such scales. Therefore, we cannot be confident that temperature decline after overshoot is achievable within the timescales expected today. Only rapid near-term emission reductions are effective in reducing climate risks.

DOI: 10.1038/s41586-024-08020-9

Source: https://www.nature.com/articles/s41586-024-08020-9