Jet contrails may cool the planet by day and warm it by night

Taking a day flight could be a swift way to limit the climate impact of a holiday, as new research suggests vapour trails produced by jets can cool the planet during the daytime.

Soot particles emitted by jet engines can trigger the formation of ice crystals, causing a condensation trail that can spread and last for hours. These persistent contrails, as they are known, help to reflect solar radiation back to space, which has a cooling effect. But they also block heat from escaping from…