Airplanes and global warming article in today's USA Today:
http://www.usatoday.com/money/biztra...ion-usat_x.htm
Aviation and the environment are on a collision course. The number of airline flights worldwide is growing and expected to skyrocket over the coming decades. Aircraft emissions pollute the air and threaten by 2050 to become one of the largest contributors to global warming, British scientists have concluded.
Remember the days after 9/11. No airplanes. None. Scientists had an unprecedented opportunity for study.
Cowperson