NATURE GEOSCIENCE | ADVANCE ONLINE PUBLICATION | www.nature.com/naturegeoscience 1

news & views Precipitation extremes are expected to increase with global warming. The atmosphere can hold about 6–7 % more water vapour per °C of warming before saturation occurs1, potentially allowing more water to accumulate into a downpour. This dependency follows from basic atmospheric thermodynamics, and is termed the Clausius–Clapeyron relation. To first order, changes in precipitation extremes might be expected to follow Clausius–Clapeyron scaling2. However, ample evidence for deviations from this relationship has emerged3–5. Writing in this issue, O’Gorman6 found that the huge range — between close to zero and 25 % per °C of warming — o