WASHINGTON, July 26, 2017 - After leveling off from 1999 to 2006, global methane levels have been reaching new highs. And, according to the National Oceanic and Atmospheric Administration (NOAA), the methane concentration is coming from agricultural and wetland emissions from the tropics rather than fossil fuels. Scientists say there is a small chance this could lead to extinction-level global warming, as huge amounts of methane are released from thawing permafrost and underwater methane hydrates in the Arctic. “The region most sensitive to increased methane emissions from climate change is the Arctic,” says Ed Dlugokencky, a research chemist with NOAA's Earth System Research Center. Initially, the increased methane levels seemed to coincide with the rapid deployment of fracking. However, scientists found that the methane being analyzed does not consist of the “heavy” carbon released in the production of natural gas. NOAA hypothesizes that gas’s abundance may vary over time as it stabilizes itself.