Increases in Water Balance‐Derived Catchment Evapotranspiration in Germany During 1970s–2000s Turning Into Decreases Over the Last Two Decades, Despite Uncertainties

Understanding variations in catchment evapotranspiration ( E C ) is critical as it directly affects water availability for humans and ecosystems. Previous studies found increases in E C in Central Europe over recent decades, but fixed study periods may not fully reveal inter‐decadal hydroclimatological variability. We performed a multi‐temporal trend analysis of water balance‐derived E C for 461 German catchments and the period 1964–2019. We accounted for previously often neglected changes in storage and uncertainties in precipitation. E C generally increased throughout Germany during 1970s–2000s (>2 mm year −2 ), while it showed milder changes and decreases afterward. These variations were robust to uncertainties in precipitation (median relative uncertainty of 26%) and broadly coherent with sparse plot‐scale data. Variations in E C were related with variations in precipitation and radiation, with a potentially increasing influence of precipitation after 2000s. These findings provide a reference for synthesizing current knowledge on variations in E C and their uncertainties.