Details

Autor(en) / Beteiligte

• Liu, Mengmeng
• Prentice, Iain Colin
• Menviel, Laurie
• Harrison, Sandy P.

Titel

Past rapid warmings as a constraint on greenhouse-gas climate feedbacks

Ist Teil von

• Communications earth & environment, 2022-12, Vol.3 (1), p.1-10, Article 196

Ort / Verlag

London: Nature Publishing Group

Erscheinungsjahr

2022

Link zum Volltext

Quelle

Alma/SFX Local Collection

Beschreibungen/Notizen

• Abstract There are large uncertainties in the estimation of greenhouse-gas climate feedback. Recent observations do not provide strong constraints because they are short and complicated by human interventions, while model-based estimates differ considerably. Rapid climate changes during the last glacial period (Dansgaard-Oeschger events), observed near-globally, were comparable in both rate and magnitude to current and projected 21st century climate warming and therefore provide a relevant constraint on feedback strength. Here we use these events to quantify the centennial-scale feedback strength of CO 2 , CH 4 and N 2 O by relating global mean temperature changes, simulated by an appropriately forced low-resolution climate model, to the radiative forcing of these greenhouse gases derived from their concentration changes in ice-core records. We derive feedback estimates (expressed as dimensionless gain) of 0.14 ± 0.04 for CO 2, 0.10 ± 0.02 for CH 4 , and 0.09 ± 0.03 for N 2 O. This indicates that much lower or higher estimates of gains, particularly some previously published values for CO 2 , are unrealistic.