A study in the journal Nature Climate Change by researchers from the University of Reading's Department of Meteorology has said the world's present design of aircraft may lower the formation of their distinctive condensation trails (contrails) if they choose their flight paths.
Researchers said aircraft will be able to lessen their contributions to global warming by avoiding the places where the thinly shaped clouds contrails are produced. However, flying further could mean emitting more carbon dioxide.
"If we can predict the regions where contrails will form, it may be possible to mitigate their effect by routing aircraft to avoid them," Emma Irvine of the university's Department of Meteorology said.
Contrails are those crisscrossed steam-like images seen on a clear blue sky trailing behind an aircraft. They sometimes stay up in the air for many hours. Scientists said these contrails help trap infrared energy in the atmosphere.
"Our work shows that for a rounded assessment of the environmental impact of aviation, more needs to be considered than just the carbon emissions of aircraft," Irvine said.
Researchers said smaller aircraft can fly much further to avoid forming contrails than larger aircraft. For example, for a small aircraft that is predicted to form a contrail 20 miles (32km) long, if an alternative route adds less than 200 miles (322 km) onto the route - 10 times the length of contrail that would have been produced - then the alternative route would have a smaller climate impact.
The study noted larger aircrafts emit more carbon dioxide than smaller aircraft for each mile flown. The alternative route can still be applicable, provided it adds less than 60 miles (i.e. 3 times the contrail length) onto the route.
"Contrails may last for several hours, while carbon dioxide can last for decades. In terms of mitigating these impacts, air traffic control agencies would need to consider whether such flight-by-flight re-routing is feasible and safe and weather forecasters would need to establish if they can reliably predict when and where contrails are likely to form," Irvine said.