Severe water pollution in rivers across Asia, resulting from rapid urbanisation and poor wastewater management, has rarely been linked to carbon (C) export and greenhouse gas (GHG) emissions. This project aimed to build a research network focusing on C fluxes through Asian river systems to assess water pollution impacts on riverine GHG emissions. The researchers took a unique approach combining synthesis workshops and exploratory field studies. Each year a workshop was held in a regional hub of the Mekong, Ganges, and Yellow River to synthesise monitoring data available from local sources and conduct a field trip followed by seasonal sampling surveys. Standardised monitoring protocols were disseminated among project members and research communities via a technical workshop session and a project webpage. Comparing literature information and local data with new field measurements suggests that rising organic pollution in rivers and tributaries downstream of metropolitan areas across the region has greatly increased organic C and GHG fluxes over the recent decades. These results call for concerted efforts among scientists and water agencies that can properly assess water pollution impacts on regional and global river carbon budgets and explore alternative policies for mitigating wastewater-induced increases in riverine GHG emissions.