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Identifying global climate change using simple indices
Author(s) -
Karoly David J.,
Braganza Karl
Publication year - 2001
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/2000gl011925
Subject(s) - climatology , climate change , environmental science , climate model , mean radiant temperature , climate commitment , abrupt climate change , greenhouse gas , climate sensitivity , global warming , transient climate simulation , climate oscillation , atmospheric sciences , effects of global warming , geology , oceanography
Several simple indices of surface air temperature patterns are used to describe global climate variability and change. The indices include the land‐ocean temperature contrast, the hemispheric contrast, the meridional gradient, and the magnitude of the seasonal cycle, as well as the global‐mean temperature. The behaviour of the indices is investigated using global observational data for the period 1881–1994 and long control and anthropogenic climate change simulations with two different climate models. The indices represent the key features of the “fingerprint” of greenhouse climate change. For natural climate variations, they contain information independent of the global‐mean temperature. The observed trends over the last 40 years in all the indices, except for the hemispheric contrast, are unlikely to have occurred due to natural climate variations and all are consistent with model simulations of anthropogenic climate change.