Dec 4, 2017

Precipitation variability increases in a warmer climate

Angeline G. Pendergrass, Reto Knutti, and Flavio Lehner
Scientific Reports
  • Shows that precipitation variability in most climate models increases over a majority of global land area in response to warming (66% of land has a robust increase in variability of seasonal-mean precipitation)
  • Compares recent decades to RCP8.5 projections for the end of the 21st century
  • Finds that in the global, multi-model mean, precipitation variability increases 3-4% K-1 globally, 4-5% K-1 over land and 2-4% K-1 over ocean, and is remarkably robust on a range of timescales from daily to decadal
  • Finds that precipitation variability increases by at least as much as mean precipitation and less than moisture and extreme precipitation for most models, regions, and timescales
  • The authors interpret this as being related to an increase in moisture which is partially mitigated by weakening circulation
  • Shows that changes in observed daily variability in station data are consistent with increased variability