Oct 9, 2013

Attributing intensification of precipitation extremes to human influence

by
Xuebin Zhang, Hui Wan, Francis W. Zwiers, Gabriele C. Hegerl, Seung‐Ki Min
,
Geophysical Research Letters
  • Provides estimates of the human contribution to the observed widespread intensification of precipitation extremes
  • Considers the annual maxima of daily (RX1day) and 5 day consecutive (RX5day) precipitation amounts over the Northern Hemisphere land area for 1951–2005
  • Compares observed changes with expected responses to external forcings as simulated by multiple coupled climate models participating in Coupled Model Intercomparison Project Phase 5
  • Detects the effect of anthropogenic forcings in extreme precipitation observations, both individually and when simultaneously estimating anthropogenic and naturally forced changes
  • Finds that the effect of natural forcings is not detectable
  • Estimates that human influence has intensified annual maximum 1 day precipitation in sampled Northern Hemisphere locations by 3.3% [1.1% to 5.8%, >90% confidence interval] on average
  • Concludes that this corresponds to an average intensification in RX1day of 5.2% [1.3%, 9.3%] per degree increase in observed global mean surface temperature consistent with the Clausius‐Clapeyron relationship