The first deal limiting greenhouse gases from international aviation has been sealed after years of discussions.

From 2020 any increase in airline CO2 emissions will be offset by activities, like tree planting, which help to soak up CO2.

The aviation deal was agreed in Montreal by national representatives at the International Civil Aviation Organisation, ICAO, and comes in just after the Paris agreement to stabilise climate change passed a key threshold for becoming law.

This offsetting proposal has been labelled controversial. Airlines are striving to make planes more efficient, but the industry can't innovate fast enough to contain its growth. International aviation is responsible for putting more carbon dioxide into the atmosphere every year than the whole of the UK.