Uncertainties of carbon emission from hydroelectric reservoirs

Anthropogenic greenhouse gas (GHG) emissions have substantially contributed to intensification of heavy precipitation and thus the risk of flood occurrence, and this anthropogenic climate change is now likely to continue for many centuries. Thus, precise quantification of human-induced GHG emissions is urgently required for modeling future global warming and precipitation changes, which is strongly linked to flood disasters. Recently, GHG evasion from hydroelectric reservoirs was estimated to be 48 Tg C as CO2 and 3 Tg C as CH4 annually, lower than earlier estimate (published in Nature Geoscience; 2011). Here, we analyzed the uncertainties of GHG emissions from hydroelectric reservoirs, that is, reservoir surface area, data paucity and carbon emission relating to ecological zone, and argued that GHG evasion from global hydroelectric reservoirs has been largely under-estimated. Our study hopes to improve the quantification for future researches.