Satellite Laser Altimetry Reveals a Net Water Mass Gain in Global Lakes With Spatial Heterogeneity in the Early 21st Century

Abstract

Lake water storage changes are important factors that influence the climate, hydrological cycle, and environments. However, long-term estimation of global lake storage changes is challenging because historical in-situ hydrological observations worldwide are rarely available. Benefiting from the laser altimeter ICESat and ICESat-2, we comprehensively assessed water level and volume changes in global natural lakes larger than 10 km2 during 2003–2020. The 6,567 lakes observable by ICESat/ICESat-2, which account for ∼94% of the total global lake volume, showed a total water storage increase of 10.88 ± 16.45 Gt/yr during 2003–2020, and the estimate reaches 16.12 ± 20.41 Gt/yr when also taking account of the remaining unobserved lakes. Despite water gains in most natural lakes, large lakes under dry and high water-stress conditions experienced dramatic water loss in general. Presumably, these drying lakes may continue to shrink with a warming climate and continuously increasing water demands in the future without further action.