Linking methane emissions inventories with atmospheric observations

Hristov et al. argue that our study “provides a comprehensive, quantitative analysis of anthropogenic methane sources,” but that the conclusion “that US EPA [US Environmental Protection Agency] estimates for livestock methane emissions are grossly underestimated appears to be unsubstantiated by ... [a] ‘bottom-up’ approach” outlined in their letter. In this reply, we discuss the information provided by atmospheric methane data about methane emissions, and comment on the challenge of connecting “bottom-up” and “topdown” estimates, a conclusion shared Hristov et al.