Do short-duration precipitation extremes follow observed temperature trends as predicted by the Clausius-Clapeyron relation?

The Clausius-Clapeyron (CC) relation has - over the past two decades - been extensively discussed as a benchmark for the scaling of short duration rainfall extremes [1-3]. Recent work [4], using a large dataset from Germany, suggests that both convective and stratiform extremes scale approximately at the Clausius-Clapeyron rate of 7%/K when detecting the two types individually at high temporal and spatial resolution. Here we ask if such short-duration extremes also respond at similar rates to the observed temperature trends in Germany over the past 30 years. Indeed, over this timespan, our analysis shows a pronounced warming trend for Germany. However, short-duration precipitation extremes display relatively modest increases or no detectable increase during the same period. Conditioning on temperature at (dry) intervals leading up to precipitation events we find that the temperature trend of this conditioned dataset is also far more modest. In line with previous reports we find relative humidity to remain all but constant. Our results imply that, whereas mean and extreme temperatures in Germany increase markedly with global warming, changes in rainfall extremes may be much more gentle as the occurrence of rainfall appears to be tied to moderate temperatures. Deeper mechanistic understanding of the exact conditions for rainfall initiation under global warming, perhaps using cloud-resolving models, would therefore be useful for the projection of future meteorological flood risk.   

 

[1] Lenderink, Geert, and Erik Van Meijgaard. "Increase in hourly precipitation extremes beyond expectations from temperature changes." Nature Geoscience 1.8 (2008): 511-514.

[2] Haerter, Jan O., and P. Berg. "Unexpected rise in extreme precipitation caused by a shift in rain type?." Nature Geoscience 2.6 (2009): 372-373.

[3] Berg, Peter, Christopher Moseley, and Jan O. Haerter. "Strong increase in convective precipitation in response to higher temperatures." Nature Geoscience 6.3 (2013): 181-185.

[4] Da Silva, Nicolas A., and Jan O. Haerter. "Super-Clausius–Clapeyron scaling of extreme precipitation explained by shift from stratiform to convective rain type." Nature Geoscience (2025).