Inland waters such as rivers, lakes, reservoirs, and ponds may release copious amounts of greenhouse gases, but this possibility is not well understood. In a new review published in theJournal of Geophysical Research: Biogeosciences, Qianqian Yang and colleagues summarize what's known about carbon dioxide and methane release from China's inland waterways and suggest that a widespread monitoring network could help researchers understand this important aspect of climate change.