Upper-Atmosphere Climate Processes

Carbon dioxide can warm the surface while cooling the stratosphere, because increased CO2 makes it easier for the thin upper atmosphere to radiate infrared energy to space.

Research involving Columbia University and Lamont-Doherty Earth Observatory has refined this mechanism and examined the roles of altitude, wavelength, ozone, and water vapor. Related work asks how stratospheric cooling changes nitrous oxide chemistry and how trace gases affect cloud-droplet formation. These processes matter because climate models must represent radiation, atmospheric chemistry, circulation, and cloud interactions accurately to project climate responses.