The Climate Costs of Contrails

Americal Geographic Union GeoSpace Blog, December 17th, 2009.

Trucks belching emissions are obnoxious, but I don’t feel the same disgust when I see fluffy white contrails in the sky. Maybe I should.

Contrails are the artificial clouds formed by condensation of water and emissions from plane engines. New insights into their effects on climate were discussed during session A42A: Climate and Chemistry Impacts of Aviation and Aerospace Emissions I. Contrails form in ice supersaturation regions in the sky, where the relative humidity is over 100 percent. Their presence changes the sky’s radiative forcing, the energy balance between incoming and outgoing radiation, measured in Watts per square meter. Positive forcing warms the system, while a negative numbers tends to cool it. Read More >