Aircraft Effects -- Summary
Based on what is known of the radiative properties of jet aircraft contrails, Meerkotter et al. (1999) have concluded that their presence tends to cool the earth's surface during daylight hours and warm it at night. On the other hand, Boucher (1999) has determined that between 1982 and 1991, the global amount of cirrus cloud increased by 1.1% over land and 3.5% over the sea, and that this (supposedly) aircraft-induced phenomenon (because it was most pronounced over the principal flight corridors) has a net warming effect on the planet. More must clearly be learned before the final word is written on the climatic effects of aircraft traffic.
Based on what is known of the radiative properties of jet aircraft contrails, Meerkotter et al. (1999) have concluded that their presence tends to cool the earth's surface during daylight hours and warm it at night. On the other hand, Boucher (1999) has determined that between 1982 and 1991, the global amount of cirrus cloud increased by 1.1% over land and 3.5% over the sea, and that this (supposedly) aircraft-induced phenomenon (because it was most pronounced over the principal flight corridors) has a net warming effect on the planet. More must clearly be learned before the final word is written on the climatic effects of aircraft traffic.
References
Boucher, O. 1999. Air traffic may increase cirrus cloudiness. Nature 397: 30-31.
Meerkotter, R., Schumann, U., Doelling, D.R., Minnis, P., Nakajima, T. and Tsushima, Y. 1999. Radiative forcing by contrails. Annales Geophysicae 17: 1080-1094.