Lorenzo Polvani Professor of Applied Mathematics and Earth & Environmental Sciences Columbia University
Why has the lower stratosphere stopped cooling for the last 20 years?
The cooling of the stratosphere is an important fingerprint of CO2 on the climate system. This stratospheric signature of CO2, however, is confounded by the presence of ozone-depleting substances (ODS). The talk will summarize the latest observations and, with simple arguments and with the help of ensembles of chemistry-climate model integrations, demonstrate the crucial role of ODS not only on stratospheric temperature trends, but also on the entire large-scale circulation of the stratosphere.
