How much pollution do airplanes emit?
Every airplane is equipped with several engines that are burning fuels and emitting exhaust fumes. Most of the exhaust is water vapor, which quickly turns to ice crystals in the upper atmosphere. This exhaust can be seen as contrails or line clouds formed behind the airplane as it flies overhead. Aircraft engines emit carbon particles, sulfur dioxides, and oxides of nitrogen. Carbon monoxide emitted from planes accounts for ~3% of the planet-wide total of this pollutant. The quantity of pollutants emitted changes each time the plane is flown, since aircraft performance changes with pressure and temperature, therefore measurements of pollution aren’t easily made.
