Uncertainty in Empirical Climate Sensitivity Estimates 1850-2017

Abstract

Atmospheric CO2 concentrations and surface temperature reconstructions in the study period 1850-2017 are used to estimate observed equilibrium climate sensitivity. Comparison of climate sensitivities in the first and second halves of the study period and a study of climate sensitivities in a moving 60-year window show that the estimated values of climate sensitivity are unstable and unreliable and that therefore they may not contain useful information. These results are not consistent with the existence of a climate sensitivity parameter that determines surface temperature according to atmospheric CO2 concentration.

Keywords: equilibrium climate sensitivity, greenhouse effect, atmospheric carbon dioxide, fossil fuel emissions, anthropogenic global warming, climate change, extreme weather, sea level rise, catastrophic consequences of climate change