Unprecedented Continental Drying, Shrinking Freshwater Availability, and Increasing Land Contributions to Sea Level Rise

Changes in terrestrial water storage (TWS) are a critical indicator of freshwater availability. We use NASA GRACE/GRACE-FO data to show that the continents have undergone unprecedented TWS loss since 2002. Areas experiencing drying increased by twice the size of California annually, creating ‘mega-drying’ regions across the northern hemisphere. While most of the world’s dry/wet areas continue to get drier/wetter, dry areas are now drying faster than wet areas are wetting. Changes in TWS are driven by high-latitude water losses, intense Central American/European droughts, and groundwater depletion, which accounts for 74% of TWS loss over non-glaciated continental regions. ‘Continental drying’ is having profound global impacts. 75% of the population lives in 106 countries that have been losing freshwater water since 2002. Furthermore, the continents now contribute more freshwater to sea level rise than the ice sheets, and drying regions now contribute more than land glaciers and ice caps. Urgent action is required to prepare for the major impacts of results presented.