Details

Autor(en) / Beteiligte

• Cooper, Vincent T
• Armour, Kyle C
• Hakim, Gregory J
• Tierney, Jessica E
• Osman, Matthew B
• Proistosescu, Cristian
• Dong, Yue
• Burls, Natalie J
• Andrews, Timothy
• Amrhein, Daniel E
• Zhu, Jiang
• Dong, Wenhao
• Ming, Yi
• Chmielowiec, Philip

Titel

Last Glacial Maximum pattern effects reduce climate sensitivity estimates

Ist Teil von

• Science advances, 2024-04, Vol.10 (16), p.eadk9461-eadk9461

Ort / Verlag

United States: American Association for the Advancement of Science

Erscheinungsjahr

2024

Quelle

EZB Electronic Journals Library

Beschreibungen/Notizen

• 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.