Getting rid of roomy business-class and first-class seats in planes could more than halve the aviation industry’s emissions, researchers have claimed.

If planes only had economy seating, this could reduce emissions by up to 56.7% (nearly three-fifths), a new report says. Even more savings could be made if airlines made sure that flights were as full as possible.

Wealthy passengers sitting in pricier sections of planes are responsible for more carbon emissions than those in economy class because they take up more room. Rich people tend to fly more often too, so their effect on climate change is much greater.

Since airline passenger numbers are predicted to double by 2050, the industry needs to find ways of reducing emissions. It’s unlikely that large passenger planes will be powered by batteries any time soon, and many experts say that so-called sustainable aviation fuels (SAFs) are unlikely to be a big help either.