Crook, JA and Forster, PM (2011) A balance between radiative forcing and climate feedback in the modeled 20th century temperature response. Journal of Geophysical Research-Atmospheres, 116. ISSN 0148-0227Full text available as:
Available under licence : See the attached licence file.
In this paper, we breakdown the temperature response of coupled ocean-atmosphere climate models into components due to radiative forcing, climate feedback, and heat storage and transport to understand how well climate models reproduce the observed 20th century temperature record. Despite large differences between models' feedback strength, they generally reproduce the temperature response well but for different reasons in each model. We show that the differences in forcing and heat storage and transport give rise to a considerable part of the intermodel variability in global, Arctic, and tropical mean temperature responses over the 20th century. Projected future warming trends are much more dependent on a model's feedback strength, suggesting that constraining future climate change by weighting these models on the basis of their 20th century reproductive skill is not possible. We find that tropical 20th century warming is too large and Arctic amplification is unrealistically low in the Geophysical Fluid Dynamics Laboratory CM2.1, Meteorological Research Institute CGCM232a, and MIROC3.2(hires) models because of unrealistic forcing distributions. The Arctic amplification in both National Center for Atmospheric Research models is unrealistically high because of high feedback contributions in the Arctic compared to the tropics. Few models reproduce the strong observed warming trend from 1918 to 1940. The simulated trend is too low, particularly in the tropics, even allowing for internal variability, suggesting there is too little positive forcing or too much negative forcing in the models at this time. Over the whole of the 20th century, the feedback strength is likely to be underestimated by the multimodel mean.
|Copyright, Publisher and Additional Information:||© 2011 American Geophysical Union. Reproduced in accordance with the publisher's self-archiving policy.|
|Keywords:||estimating signal amplitudes, mean surface-temperature, anthropogenic forcings, coupled models, part I, sensitivity, early-20th-century, attribution, simulations, well|
|Institution:||The University of Leeds|
|Academic Units:||The University of Leeds > Faculty of Environment (Leeds) > School of Earth and Environment (Leeds)|
|Depositing User:||Symplectic Publications|
|Date Deposited:||10 Oct 2011 10:16|
|Last Modified:||08 Jun 2014 20:46|
|Publisher:||American Geophysical Union|