But the first study to look into the combined effect of both global warming and deforestation found most species are in danger of extinction.

The study by the Carnegie Institution for Science in Washington predicted that by 2100 only 18 to 45 per cent of the plants and animals in tropical forests may exist as they are today.

This will mean that most will have to adapt, move or die.

The scientists calculated the threat to rainforests from drought or forest fires as the world warms by looking at 16 different climate change models from research centres around the world.

They also studied the threat of deforestation by looking at satellite imagery showing the rate of illegal logging.

The worst affected areas will be the Amazon, followed by the rainforests in Africa and Indonesia.

Daniel Nepstad, an ecologist at the Woods Hole Research Center in Massachusetts, said only a cut in greenhouse gases can save the world’s wildlife.

"This study is the strongest evidence yet that the world's natural ecosystems will undergo profound changes — including severe alterations in their species composition — through the combined influence of climate change and land use," he said.

“Conservation of the world's biota, as we know it, will depend upon rapid, steep declines in greenhouse gas emissions."