Nature: Atmospheric levels of the potent greenhouse gas methane rose sharply in early 2007, having remained largely stable over the past decade. Methane is released from wetlands and wildfires as well as from human activities, such as fossil fuel use and farming, but is destroyed in the atmosphere through reaction with a compound known as the hydroxyl radical. Now Matthew Rigby of the Massachusetts Institute of Technology and colleagues have examined the change in global emissions of methane …