Scientists at NASA have found that cirrus clouds created by contrails from engine exhaust are capable of increasing average surface temperatures enough to cause a warming trend in the United States.

Image courtesy NASA Langley Research Center

“This enhanced infrared image from the Moderate Resolution Imaging Spectroradiometer (MODIS), aboard NASA’s Terra satellite, shows widespread contrails over the southeastern United States during the morning of January 29, 2004.” – NASA Earth Observatory