Evaporative water loss of 1.42 million global lakes

Evaporative loss from global lakes and reservoirs is a key component of terrestrial water and energy balance, yet its volume, spatial distribution, and long-term trends have been poorly constrained. Using satellite observations and modeling, the study quantified monthly evaporation volume for 1.42 million lakes (1985–2018). The long-term average lake evaporation is 1500 ± 150 km³ year⁻¹, increasing at 3.12 km³ year⁻¹ (≈31.2 km³ decade⁻¹; 2.1 ± 1.6% decade⁻¹). Trends are attributed to increasing evaporation rate (58%), decreasing lake ice coverage (23%), and increasing lake surface area (19%). Although reservoirs hold only ~5% of global lake storage, they contribute 16% (≈235 km³ year⁻¹) of total evaporative loss and have increased at 5.4% decade⁻¹. Results underscore the need to use evaporation volume, rather than rate alone, to assess climatic impacts on lake systems.