May 9, 2019

Global and Regional Increase of Precipitation Extremes under Global Warming

Simon Michael Papalexiou and Alberto Montanari
Water Resources Research

By introducing a new approach to analyzing extremes, using thousands of rain records, we reveal a clear increase in the frequency extreme rain events over the recent 50 years when global warming accelerated. This upward trend is highly unlikely to be explained by natural climatic variability. The probability of this happening is less than 0.3 per cent under the model assumptions used.

Simon Papalexiou, lead author

Our results are in line with the assumption that the atmosphere retains more water under global warming. The fact that the frequency, rather the magnitude, of extreme precipitation is significantly increasing has relevant implications for climate adaptation. Human systems need to increase their capability to react to frequent shocks.

Alberto Montanari, co-author

  • Finds that the number of extreme downpours increased steadily between 1964 and 2013 — a period when global warming also intensified
  • Finds that the frequency of 'extreme precipitation events' increased in parts of Canada, most of Europe, the Midwest and northeast region of the U.S., northern Australia, western Russia and parts of China
  • Looks at over 8,700 daily rain records from 100,000 stations monitoring rain worldwide and finds that the frequency of torrential rain between 1964 and 2013 increased as the decades progressed
  • Finds that between 2004 and 2013, there were seven percent more extreme bouts of heavy rain overall than expected globally; in Europe and Asia, there were 8.6 percent more 'extreme rain events' overall, during this decade.