Stronger influences of increased CO2 on subdaily precipitation extremes than at the daily scale

Abstract

Based on idealized experiments (preindustrial control experiment (PI) and 1% yr−1 increase (1%CO2) in atmospheric CO2) from 10 general circulation models produced under the Coupled Model Intercomparison Project Phase 5 and using the fraction of attributable risk, we examine the CO2 effects on extreme precipitation at the subdaily and daily scales. We find that the increased CO2 concentration substantially increases the odds of the occurrence of subdaily precipitation extremes compared to the daily scale in most areas of the world, with the exception of some regions in the subtropics, likely in relation to the subsidence of the Hadley Cell. These results point to the large role that atmospheric CO2 plays in extreme precipitation under an idealized framework.