Climate change: How do scientists think we can better look after our planet?
For a long time, scientists have been warning that planes, cars and burning fossil fuels are a major cause of climate change.
But there are now warnings that how we use land is also playing a part, because soil used for grazing animals and growing crops is producing carbon dioxide, a greenhouse gas.
Experts think that between a quarter and a third of all greenhouse gas emissions come from how we use land.
This news came from a special United Nations summit called the Intergovernmental Panel on Climate Change which was held in Geneva in Switzerland in August 2019.
It's ahead of a big climate meeting in New York, involving many of the world's leaders.
BBC reporter Roger Harrabin was there and can tell us three big things we've learnt from their meeting.