1Department of Meteorology, University of Reading, Earley Gate, P.O. Box 243, Reading RG6 6BB, UK
2Department of Mathematics, University of Reading, Whiteknights, P.O. Box 220 Reading RG6 6AX, UK
3Walker Institute for Climate System Research, University of Reading, Reading RG6 6AR, UK
4Meteorologisches Institut, Klima Campus, University of Hamburg, Grindelberg 5, 20144 Hamburg, Germany
Received: 24 Dec 2009 – Discussion started: 09 Feb 2010
Abstract. Using a recent theoretical approach, we study how global warming impacts the thermodynamics of the climate system by performing experiments with a simplified yet Earth-like climate model. The intensity of the Lorenz energy cycle, the Carnot efficiency, the material entropy production, and the degree of irreversibility of the system change monotonically with the CO2 concentration. Moreover, these quantities feature an approximately linear behaviour with respect to the logarithm of the CO2 concentration in a relatively wide range. These generalized sensitivities suggest that the climate becomes less efficient, more irreversible, and features higher entropy production as it becomes warmer, with changes in the latent heat fluxes playing a predominant role. These results may be of help for explaining recent findings obtained with state of the art climate models regarding how increases in CO2 concentration impact the vertical stratification of the tropical and extratropical atmosphere and the position of the storm tracks.
Revised: 21 Jul 2010 – Accepted: 02 Oct 2010 – Published: 18 Oct 2010
Lucarini, V., Fraedrich, K., and Lunkeit, F.: Thermodynamics of climate change: generalized sensitivities, Atmos. Chem. Phys., 10, 9729-9737, doi:10.5194/acp-10-9729-2010, 2010.