Transient response of severe convective storm forcing associated with global increases in greenhouse gas concentrations

Motivated by our previous research that utilized climate-model time slices, we investigate here the transient response of severe, extratropical thunderstorm forcing to time-increasing greenhouse gas (GHG) concentrations. Using a five-member ensemble of global climate model experiments, we find a positive trend in such forcing, within the United States, over the period 1950-2099. The rate of increase varies by geographic region, depending on (i) low-level water vapor availability and transport, and (ii) the frequency of synoptic-scale cyclones during the warm season. A synthesis of our results and theory provides a simple yet compelling dynamical explanation for the potential response of hazardous convective weather to anthropogenically enhanced GHGs.