Jet Biofuel Enlisted for Contrail Control
“Contrails might be a punch line in the culture these days, thanks to the imaginative folks who have rechristened them “chemtrails” and embroidered them with elaborate theories involving government and corporate misdeed. But contrails are pretty serious business for a less conspiratorial reason: scientists believe these ice clouds generated by water exhaust gases from aircraft engines could have a real impact on the climate, perhaps by cooling temperatures during the day and warming them at night.When contrails spread to form cirrus clouds, they can persist for hours and extend over areas of several square kilometers. These “contrail cirrus,” which artificially increase Earth’s cloudiness and become almost indistinguishable from natural cirrus, are among the most uncertain contributors to the Earth’s radiative forcing. (Radiative forcing is defined as the change of the net radiating flux resulting from changes in the atmospheric composition. A measure of the perturbation of Earth-atmosphere energy budgets, it is widely used as a climate metric).”
Three different fuel types are discussed: a low-sulfur JP-8 fuel, a 50:50 blend of JP-8 and a camelina-based HEFA fuel, and the JP-8 fuel doped with sulfur.
Richard H. Moore et al. “In-Situ Measurements of Contrail Properties Measured During the 2013-2014 ACCESS Project,” 14th Conference on Cloud Physics, July 2014.
Bruce Anderson, “Alternative-Fuel Effects on Contrails & Cruise EmiSSions (ACCESS-2) Flight Experiment.” NASA LaRC and the ACCESS-II Science and Implementation Teams, January 2015;