Anthropogenic Influences on the Intensity and Rainfall of Major Tropical Cyclone Events

There is no consensus on whether anthropogenic climate change has yet impacted tropical cyclone (TC) statistics, in part because natural variability is large and consistent TC observations cover only a few decades. In addition, projections of future TC activity are uncertain, as they often rely on coarse-resolution climate models that parameterize convection and have difficulty representing intense TCs. Here we investigated how historically destructive TCs could change if similar events occurred in pre-industrial and future climates, using convection-permitting regional climate model simulations. We found that climate change to date enhanced average and extreme rainfall of Hurricanes Katrina, Irma, Maria, but did not change TC intensity. In addition, continued anthropogenic warming robustly increases wind speed and rainfall of intense TCs among 15 events sampled globally. Additional simulations suggest that convective parameterization introduces minimal uncertainty into the sign of projected TC intensity and rainfall changes, supporting confidence in projections from models with parameterized convection and TC-permitting resolution.