Editor's Summary
15 June 2006
Flight plan
Condensation trails, or contrails, produced by high-flying aircraft have an effect on the Earth's energy balance similar to that of high thin ice clouds. They trap outgoing long-wave radiation from the Earth and atmosphere and reflect incoming solar radiation. On average, the long-wave effect prevails and the net effect is warming. The effect is small compared with those due to other emissions, but with air traffic on the increase it is important to understand the phenomenon. A study of the skies above southeast England shows that the effect critically depends on when contrails form. Night flights account for up to 80% of contrail-induced warming even though only a quarter of flights occur at night. And half the year's contrail warming comes in a 3-month winter season. The radiative properties of contrails and their short lifetime mean that the climate impact caused by this aspect of aviation could be minimized by some flight rescheduling.
Letter: The importance of the diurnal and annual cycle of air traffic for contrail radiative forcing
Nicola Stuber, Piers Forster, Gaby Rädel and Keith Shine
doi:10.1038/nature04877
