美国华盛顿大学
据研究人员介绍，在考虑温度模式后，末次盛冰期(LGM)对平衡气候敏感性(ECS)提供了更强的约束，即温室气体增加导致的全球变暖。控制ECS的反馈取决于地表温度的空间模式(“模式效应”)，因此，使用LGM来限制未来变暖，需要量化在LGM变冷与现代变暖期间温度模式产生不同的反馈。
研究结合数据同化重建和大气模型表明，气候对LGM作用力更为敏感，因为冰盖放大了反馈不稳定的温带变冷。仅从LGM证据来看，考虑到LGM模式效应，现代ECS中值为2.4°C，66%范围为1.7°至3.5°C(1.4°至5.0°C, 5%至95%)。将LGM与其他证据相结合，最佳估计值为2.9°C，66%范围为2.4°C至3.5°C(2.1°C至4.1°C, 5%至95%)，与最近的评估相比，其不确定性大大缩小。
附：英文原文
Title: Last Glacial Maximum pattern effects reduce climate sensitivity estimates
Author: Vincent T. Cooper, Kyle C. Armour, Gregory J. Hakim, Jessica E. Tierney, Matthew B. Osman, Cristian Proistosescu, Yue Dong, Natalie J. Burls, Timothy Andrews, Daniel E. Amrhein, Jiang Zhu, Wenhao Dong, Yi Ming, Philip Chmielowiec
Issue&Volume: 2024-04-17
Abstract: Here, we show that the Last Glacial Maximum (LGM) provides a stronger constraint on equilibrium climate sensitivity (ECS), the global warming from increasing greenhouse gases, after accounting for temperature patterns. Feedbacks governing ECS depend on spatial patterns of surface temperature (“pattern effects”); hence, using the LGM to constrain future warming requires quantifying how temperature patterns produce different feedbacks during LGM cooling versus modern-day warming. Combining data assimilation reconstructions with atmospheric models, we show that the climate is more sensitive to LGM forcing because ice sheets amplify extratropical cooling where feedbacks are destabilizing. Accounting for LGM pattern effects yields a median modern-day ECS of 2.4°C, 66% range 1.7° to 3.5°C (1.4° to 5.0°C, 5 to 95%), from LGM evidence alone. Combining the LGM with other lines of evidence, the best estimate becomes 2.9°C, 66% range 2.4° to 3.5°C (2.1° to 4.1°C, 5 to 95%), substantially narrowing uncertainty compared to recent assessments.
DOI: adk9461
Source: https://www.science.org/doi/10.1126/sciadv.adk9461