Aeroplanes could avoid forming planet-warming contrails by adjusting their altitude – in many cases, by just a few hundred metres. This could be one of the easiest ways to reduce the climate impacts of aviation.
“Ignoring the contrail question would be silly,” says Esther Roosenbrand at the Delft University of Technology in the Netherlands.
Aviation makes up a small but growing share of the emissions that drive global warming. As much as two-thirds of this comes…