The Overlooked Side of Climate Sensitivity
Climate sensitivity is defined as the increase in global mean temperature required to restore radiative equilibrium. Most studies of climate sensitivity focus on processes that govern the strength of radiative feedbacks, which amplify or dampen the response to a given forcing. However, in this talk I will argue that, due to its base-state dependence, radiative forcing from CO2 plays an under-appreciated role in modifying climate sensitivity. I will show that the base state dependence of CO2 forcing causes high CO2 climates to be intrinsically more sensitive than low CO2 climates. It also has potentially important implications for elucidating the causality of deep-time paleoclimates, where changes in the climatological base-state can strongly modulate the magnitude of the CO2 radiative forcing, and for geo-engineering solutions to contemporary climate change.
