Hydropower is commonly considered as a clean energy source to fuel Southeast Asian economic growth. A recent study published in Environmental Research Letters finds that hydropower in the Mekong River Basin, the largest river in Southeast Asia, might not always be climate friendly. The median greenhouse gas (GHG) emission of hydropower was estimated to be 26 kg CO2e/MWh over 100-year lifetime, which is within the range of other renewable energy sources (