Large increases in methane emissions expected from North America's largest wetland complex.

Natural methane (CH) emissions from aquatic ecosystems may rise because of human-induced climate warming, although the magnitude of increase is highly uncertain. Using an exceptionally large CH flux dataset (~19,000 chamber measurements) and remotely sensed information, we modeled plot- and landscape-scale wetland CH emissions from the Prairie Pothole Region (PPR), North America's largest wetland complex. Plot-scale CH emissions were driven by hydrology, temperature, vegetation, and wetland size. Historically, landscape-scale PPR wetland CH emissions were largely dependent on total wetland extent. However, regardless of future wetland extent, PPR CH emissions are predicted to increase by two- or threefold by 2100 under moderate or severe warming scenarios, respectively. Our findings suggest that international efforts to decrease atmospheric CH concentrations should jointly account for anthropogenic and natural emissions to maintain climate mitigation targets to the end of the century.