Plot twist in methane mystery blames chemistry, not emissions, for recent rise
Falling levels of a molecule that destroys the greenhouse gas may be behind increasing concentrations since 2007

RADICAL THEORY Changes in the concentration of a highly reactive compound in the atmosphere called hydroxyl may be to blame for a rise in global methane levels since 2007, new research suggests. Redder regions in this simulation of a typical March hydroxyl distribution contain higher concentrations of the molecule.
Angharad Stell/Univ. of Bristol