Night flights twice as bad for environment – study

A nationwide ban on night flights would significantly reduce the aviation industry’s impact on the climate, a new study shows. Scientists have found that the warming effect of aircraft is much greater when they fly in the dark, because of the effects of the condensation trails (contrails) they leave.

Piers Forster, an environmental scientist at the University of Leeds who led the project, said: “Night flights are twice as bad for the environment. If the government wanted to reduce the likely impact of aviation on climate then it could ensure that more flew during the day.”

Writing in the journal Nature today, Dr Forster and his colleagues say aircraft contrails enhance the greenhouse effect because they trap heat in the same way as clouds. During the day, their warming effect is not as pronounced because contrails reflect sunlight back into space, which helps to keep the planet cool. This means contrails are responsible for about half of the aviation industry’s impact on climate.

Dr Forster added: “Aircraft currently only have a small effect on climate. However, the fact that the volume of air traffic is set to grow rapidly in coming years makes it important to investigate the effects of contrails on our climate.”

The Guardian