When can we expect extremely high surface temperatures?

• Published in: Geophysical research letters Vol. 35; no. 14; pp. L14703 - n/a
• Main Authors: Sterl, Andreas, Severijns, Camiel, Dijkstra, Henk, Hazeleger, Wilco, Jan van Oldenborgh, Geert, van den Broeke, Michiel, Burgers, Gerrit, van den Hurk, Bart, Jan van Leeuwen, Peter, van Velthoven, Peter
• Format: Journal Article
• Language: English
• Published: Washington, DC American Geophysical Union 01-07-2008; Blackwell Publishing Ltd
• Subjects: Abrupt/rapid climate change; Earth sciences; Earth, ocean, space; Exact sciences and technology; extreme temperatures; Global Change; Global climate models; Impacts of global change; Regional climate change; South America; Middle East; Asia; Africa; North Africa; Australia; Sahel; India; extreme temperatures; Ensemble simulation; projects; Australasia; Bias; focus; Surface temperature; Climate models; climate; subtropical zone; Dynamical climatology; Scale parameter; extreme value; Reanalysis; climate change
• ISSN: 0094-8276; 1944-8007
• DOI: 10.1029/2008GL034071

In the Essence project a 17‐member ensemble simulation of climate change in response to the SRES A1b scenario has been carried out using the ECHAM5/MPI‐OM climate model. The relatively large size of the ensemble makes it possible to accurately investigate changes in extreme values of climate variables. Here we focus on the annual‐maximum 2m‐temperature and fit a Generalized Extreme Value (GEV) distribution to the simulated values and investigate the development of the parameters of this distribution. Over most land areas both the location and the scale parameter increase. Consequently the 100‐year return values increase faster than the average temperatures. A comparison of simulated 100‐year return values for the present climate with observations (station data and reanalysis) shows that the ECHAM5/MPI‐OM model, as well as other models, overestimates extreme temperature values. After correcting for this bias, it still shows values in excess of 50°C in Australia, India, the Middle East, North Africa, the Sahel and equatorial and subtropical South America at the end of the century.