Precipitation consolidation decreases terrestrial water storage

Terrestrial water availability is a key determinant of human and ecosystem well-being. Aside from mean precipitation and evaporation changes, it is unknown how daily-scale precipitation intensification and consolidation impact hydrologic partitioning and the land water balance. Using satellite-derived terrestrial water storage estimates and multiple observational precipitation datasets, we provide the first observational evidence that precipitation consolidation decreases land water availability as strongly as total precipitation enhances it across all climates globally. A transparent land surface model recovers the observed effect and reveals that it arises from enhanced evaporation due to changes in hydrologic partitioning at the land surface. Projected impacts of warming-driven rainfall consolidation at ~2°C of warming shift the land surface to abnormally dry conditions for half the global population, independent of any total precipitation changes. Our results update understanding of the determinants of the land water balance, highlighting its sensitivity to the temporal character of precipitation, with implications for water availability.