Future methane emissions from lakes and reservoirs
David Bastviken, Matthew S. Johnson
Abstract
Abstract Global lake and reservoir water surfaces were recently estimated to contribute ~10% of global methane (CH 4 ) emissions. The sensitivity of these emissions to climate and environmental change is a growing concern. Here we present data-driven, globally gridded modelling of future open-water CH 4 fluxes under different scenarios. We included multiple potential predictor variables and available peer-reviewed flux data focusing on in situ-verified relationships. The results indicate total lake and reservoir CH 4 emissions increases of 24–91% under the IPCC Shared Socioeconomic Pathway (SSP) climate change scenarios SSP1-2.6 to SSP5-8.5 by 2080–2099. Effects of changed temperature and seasonality dominated these increases. Area and nutrient load changes also contributed substantially to reservoir emissions. Large absolute changes were predicted at all latitudes. The results demonstrate the urgency in minimizing climate change to avoid substantially increased future inland water CH 4 emissions.