Claim: After the 9/11 terrorist attacks grounded commercial air traffic, "there was a temperature drop while the airplanes weren't flying, for the week afterwards."
Fact-check: Michael Gardiner says moratorium on jet flights after 9/11 caused  temperature drop over U.S.
Verdict: barely-true
Organisation: PolitiFact
Author: Tom Mooney
Date published: 2012-08-01T00:00:00