A study has found that even though modern commercial aircraft emit less carbon than their predecessors, they could be contributing more to climate change due to their longer-lived planet-warming contrails.

Contrails, or vapour trails, are line-shaped clouds produced by aircraft engine exhaust or changes in air pressure, typically at aircraft cruising altitudes several kilometres above the Earth’s surface.

While the exact warming effect of contrails is uncertain, scientists believe it is greater than warming caused by carbon emissions from jet fuel.

​Researchers at Imperial College London used machine learning to analyse satellite data on more than 64,000 contrails from a range of aircraft flying over the North Atlantic Ocean.

​Modern aircraft that fly above about 12km, such as the Airbus A350 and Boeing 787 Airliners, create more contrails than older passenger-carrying commercial aircraft, the study found.

​To reduce jet fuel consumption, modern aircraft are designed to fly at higher altitudes...