Greener fuels, electric engines, and more efficient aircraft are all being touted as ways to reduce the environmental harm of flying, but a new study suggests one simple move could help existing flights drastically cut their impact.

Getting planes to fly just a couple of thousand feet higher or lower could cut the climate impact of the contrails they leave behind by a whopping 59 percent. And only 2 percent of all scheduled flights would have to make the change for significant results.

Contrails are the white streaks you see criss-crossing the skies after an airplane has passed overhead. These cloud-like formations can have a cooling effect, acting to reflect sunlight that would otherwise heat the Earth. But they can also block outgoing heat from escaping the earth — essentially acting like a blanket, trapping heat.

Flying an airplane higher or lower could help get rid of contrails because they only form in thinner areas of atmosphere, with high humidity — so it’s theoretically possible to avoid them and reap the eco-benefits.

Researchers at the Imperial College London came to this conclusion after experimenting with computer simulations, using data available on aircraft flying in Japanese airspace. Diverging from the flight path does lead to an increase in fuel consumption, but the researchers say it’s less than a 0.1 percent rise — and the subsequent depletion in contrails offsets the extra CO2 released.

As it becomes ever more important to slash the impact of the aviation industry on the environment, alongside cleaner engine technologies and fuels, such altitude adjustment strategies are more than welcome.