Increased record-breaking precipitation events under global warming

One out of ten record-breaking rainfall events observed globally in the past thirty years can only be explained if the long-term warming is taken into account. For the last year studied, 2010, it is even one event out of four, as the trend is upward.

Dim Coumou, co-author

• Presents the first analysis of record-breaking daily rainfall events using observational data
• Shows that over the last three decades the number of record-breaking events has significantly increased in the global mean
• Finds that, globally, this increase has led to 12 % more record-breaking rainfall events over 1981–2010 compared to those expected in stationary time series
• Finds the number of record-breaking rainfall events peaked in 2010 with an estimated 26 % chance that a new rainfall record is due to long-term climate change
• Finds this increase in record-breaking rainfall is explained by a statistical model which accounts for the warming of air and associated increasing water holding capacity only
• The results suggest that whilst the number of rainfall record-breaking events can be related to natural multi-decadal variability over the period from 1901 to 1980, observed record-breaking rainfall events significantly increased afterwards consistent with rising temperatures