The authors thank Ron Stouffer, Geoff Vallis, Rong Zhang, and four anonymous reviewers for helpful comments on the manuscript. The authors also thank Brian Soden for the use of the GFDL CM2.1 radiative kernel. The authors acknowledge the international modeling groups for providing their data for analysis, the Program for Climate Model Diagnosis and Intercomparison (PCMDI) for collecting and archiving the model data, the JSC/CLIVAR Working Group on Coupled Modeling (WGCM) and their Coupled Model Intercomparison Project (CMIP) and Climate Simulation Panel for organizing the model data analysis activity, and the IPCC WG1 TSU for technical support. The IPCC Data Archive at Lawrence Livermore National Laboratory is supported by the Office of Science, U.S. Department of Energy.
Gregory, J. M., , and J. F. B. Mitchell, 1997: The climate response to CO2 of the Hadley Centre coupled AOGCM with and without flux adjustments. Geophys. Res. Lett., 24 , 1943–1946.
Gregory, J. M., and Coauthors, 2004: A new method for diagnosing radiative forcing and climate sensitivity. Geophys. Res. Lett., 31 , L03205. doi:10.1029/2003GL018747.
Houghton, J. T., , Y. Ding, , D. J. Griggs, , M. Noguer, , P. J. van der Linden, , X. Dai, , K. Maskell, , and C. A. Johnson, Eds. 2001: Climate Change 2001: The Scientific Basis. Cambridge University Press, 881 pp.
Manabe, S., , R. J. Stouffer, , M. J. Spelman, , and K. Bryan, 1991: Transient response of a coupled ocean atmosphere model to gradual changes of atmospheric CO2. Part I: Annual mean response. J. Climate, 4 , 785–818.
Meinshausen, M., , S. C. B. Raper, , and T. M. L. Wigley, 2008: Emulating IPCC AR4 atmosphere-ocean and carbon cycle models for projecting global-mean, hemispheric and land/ocean temperatures: MAGICC 6.0. Atmos. Chem. Phys. Discuss., 8 , 6153–6172.
Murphy, J. M., 1995: Transient response of the Hadley Centre coupled ocean–atmosphere mode to increasing carbon dioxide. Part III: Analysis of global-mean response using simple models. J. Climate, 8 , 496–514.
Plattner, G-K., and Coauthors, 2008: Long-term climate commitments projected with climate-carbon cycle models. J. Climate, 21 , 2721–2751.
Raper, S. C. B., , J. M. Gregory, , and R. J. Stouffer, 2002: The role of climate sensitivity and ocean heat uptake on AOGCM transient temperature response. J. Climate, 15 , 124–130.
Soden, B. J., , and I. M. Held, 2006: An assessment of climate feedbacks in coupled ocean–atmosphere models. J. Climate, 19 , 3354–3360.
Solomon, S., , D. Qin, , M. Manning, , M. Marquis, , K. Averyt, , M. M. B. Tignor, , H. L. Miller Jr., , and Z. Chen, Eds. 2007: Climate Change 2007: The Physical Science Basis. Cambridge University Press, 996 pp.
Solomon, S., , G-K. Plattner, , R. Knutti, , and P. Friedlingstein, 2009: Irreversible climate change due to carbon dioxide emissions. Proc. Natl. Acad. Sci. USA, 106 , 1704–1709.
Williams, K. D., , W. J. Ingram, , and J. M. Gregory, 2008: Time variation of effective climate sensitivity in GCMs. J. Climate, 21 , 5076–5090.
Zhang, M. H., , J. J. Hack, , J. T. Kiehl, , and R. D. Cess, 1994: Diagnostic study of climate feedback processes in atmospheric general circulation models. J. Geophys. Res., 99 , (D3). 5525–5537.