Publication Date:
2014-08-23
Description:
Palaeo data have been frequently used to determine the equilibrium (Charney) climate sensitivity S a , and — if slow feedback processes (e.g. land ice-albedo) are adequately taken into account — they indicate a similar range as estimates based on instrumental data and climate model results. Many studies assume the (fast) feedback processes to be independent of the background climate state, e.g., equally strong during warm and cold periods. Here we assess the dependency of the fast feedback processes on the background climate state using data of the last 800 kyr and a box-model of the climate system for interpretation. Applying a new method to account for background state dependency, we find S a = 0.61 ± 0.07 K (W m − 2 ) − 1 (± 1 σ ) using the latest LGMtemperature reconstruction and significantly lower climate sensitivity during glacial climates. Due to uncertainties in reconstructing the LGM temperature anomaly, S a is estimated in the range S a = 0.54 – 0.95 K (W m − 2 ) − 1 .
Print ISSN:
0094-8276
Electronic ISSN:
1944-8007
Topics:
Geosciences
,
Physics
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