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 has been held in Geneva in Switzerland.
BBC reporter Roger Harrabin was there and can tell us three big things we've learnt from their meeting.