The new methane study comes a few weeks after the release of a U.S. Geological Survey study downgraded the risks of carbon emissions from thawing Alaska permafrost and increased wildfires. According to that USGS research paper, which inventoried Alaska's carbon stores, expansion of vegetation, with its ability to lock up carbon, is expected to offset new atmospheric carbon releases through the end of the 21st century.
Methane is of special concern in global warming because it is an especially potent greenhouse gas. It has more than 25 times the heat-trapping power of carbon dioxide.The methane levels used in the study were measured from 1986 to 2015 at NOAA's Barrow Atmospheric Baseline Observatory, part of the agency's Global Greenhouse Gas Reference Network.