The only emissions scenario that achieves Paris Agreement goals in climate models assumes that methane levels have been declining since 2010, when in fact they have been rising since 2007, she said. There may be other ways of keeping climate change under 2 degrees Celsius, but they would involve compensating for rising methane with more drastic cuts to other greenhouse gases. Scientists aren’t sure why methane levels are rising. A 2017 study attributes about half of the increase to cows and other ruminant livestock, which burp methane as they digest food. Another contributing factor could be that people are releasing more fossil fuel emissions while burning less wood and other biomass. More >>