What is the pollution (mainly air pollution) caused by airplanes?

Aircraft usually fly in the stratosphere, and the pollution mainly comes from the tail gas produced by fuel combustion, such as carbon dioxide, carbon monoxide, unburned hydrocarbons and particulate matter, nitrogen oxides and so on. In addition, aircraft can also produce noise pollution.

The condensation wake refers to the "white smoke" produced behind the high-speed jet plane, which is composed of ice crystals formed by condensation of water vapor in the air and particles in the exhaust gas in cold air. It is found that the condensation trail will form cirrus (a kind of high-altitude cloud). Such clouds will hinder the emission of thermal radiation from the earth's surface, thus further aggravating global warming.