Methane Levels Are Rising, and Scientists Don't Know Why

Though researchers don't know why methane levels are currently rising, the fossil fuel industry was likely to blame in the past. (Credit: Nick Stubbs/Shutterstock)Carbon dioxide is climate change’s villainous star. But methane, an even more potent greenhouse gas, is CO2’s lesser-known evil twin. Researchers now find methane levels in the atmosphere are on an escalating upward trend. That’s a problem because emission scenarios that limit global warming to 2 degrees Celsius assum