Tropical peatlands are a known source of methane (CH 4 ) to the atmosphere, but their contribution to atmospheric CH 4 is poorly constrained. Since the 1980s, extensive areas of the peatlands in Southeast Asia have experienced land‐cover change to smallholder agriculture and forest plantations. This land‐cover change generally involves lowering of groundwater level (GWL), as well as modification of vegetation type, both of whi...