New version of Global Methane Budget published in ESSD
15 July 2020
ESSD announces publication of a new version of the Global Methane Budget (Saunois et al., https://doi.org/10.5194/essd-12-1561-2020). Although lower in atmospheric concentration than CO2, and with a much shorter atmospheric lifetime, methane represents a very potent greenhouse gas. Assembling a global methane budget requires detailed assessment of multiple land and ocean sources, of a wide array of biological and geochemical pathways, and of rapid light-driven reactions in the atmosphere. In this latest budget the methane team – more than 90 researchers from nearly 70 institutions – gathered, categorized, assessed, and (where possible) quantified natural and anthropogenic bottom-up sources and emissions (from wetlands, biota, fires, fossil fuel consumption, agriculture, permafrost, etc.) for careful comparison with top-down information (atmospheric methane concentrations from surface networks and satellites coupled with models for atmospheric chemistry and transport). Bottom-up and top-down estimates show atmospheric methane rising since the most recent (2016) budget and over the past decade, with substantial residual uncertainties due primarily to the continued challenges of quantifying methane emissions from wetlands and inland waters. These authors, working under the auspices of the Global Carbon Project, make their data and calculations freely and openly available through ESSD.