Global Dimming Finally Doesn't Get A Headline. David Travis' experiment is remarkable.

For 15 years Travis had been researching an apparently obscure topic, whether the vapour trails left by aircraft were having a significant effect on the climate. In the aftermath of 9/11 the entire US fleet was grounded, and Travis finally had a chance to find out.

It was the final piece of the puzzle that showed global dimming's link to global cooling and its effect on global warming. Air particles prevent sunlight from reaching the earth. The resulting drop in temperature is called global cooling. Travis deserves more credit. His name wasn't even mentioned in the news article or NOVA's slide show.  ¶ 9:02 AM