The planet still holds vast reserves of fossil fuel that could be extracted economically. However, according to a new analysis, a third of the world’s oil, half of its gas, and 80 percent of its coal reserves must remain unused if we are to have a good chance of avoiding potentially devastating climate change.

The study, authored by researchers at the University College of London, is the first to suggest which specific resources, and where, should be left in the ground. Importantly, it differentiates between the total amount of natural resources left in the ground and the amount of fuel it would be technologically and economically feasible to extract.