Researchers at Columbia University have identified the precise mechanism by which rising carbon dioxide levels cool the upper atmosphere. The finding accounts for decades of observed stratospheric cooling amid surface warming. Their study appears in the journal Nature Geoscience.
The stratosphere, the layer between roughly 11 and 50 kilometers above the surface, has cooled by about 2 degrees Celsius since the mid-1980s. This cooling exceeds by more than ten times the amount expected without human emissions of carbon dioxide. The process was first predicted in the 1960s by climatologist Syukuro Manabe.