Future extreme rates of warming ‘less likely’
The “pause” in global warming observed over the past decade does not significantly change estimates of the eventual, long-term, warming following a doubling of atmospheric CO2 concentrations. It indicates, however, that the immediate (transient) temperature response to rising CO2 levels may need to be slightly revised downwards.
Originating from a broad international collaboration, the study published online this week in Nature Geoscience analysed up-to-date data on global mean surface temperature, the Earth’s heat content, and radiative forcing to determine ranges for the equilibrium climate sensitivity and the transient climate response to a doubling of CO2 concentrations. While most of the climate models used in the upcoming fifth assessment of the IPCC are consistent with the data from the past decade, some more extreme versions of these current models might be less likely.