Methane is a greenhouse gas that significantly contributes to global warming. Its sources are not well constrained as many point sources are missing in emission inventories that are built based on bottom-up approaches. Emissions include sources caused by human activities (oil/gas, lifestock) but also natural ones, e.g. wetlands. The current paper fills this gap by comprehensively reviewing the capabilities of current and forthcoming satellites as powerful top-down tools to observe atmospheric methane and quantify emissions. Their most important application is to quantify anthropogenic methane sources , where there is substantial interest in identifying hot spots to reduce emissions, closing the methane budget, and to ensure compliance with international climate agreements. This paper is of broad interest for the geoscience community, as it not only presents an overview of the existing discrepancies in the atmospheric methane budget and emissions but also addresses the difficulties in defining its emission inventories on various spatial scales.