Over the next 50 years, climate change will drive thousands of viruses to jump from one species of mammal to another, according to a study published in Nature on Thursday. The shuffling of viruses among animals may increase the risk that one will jump into humans and cause a new pandemic, the researchers said.

Scientists have long warned that a warming planet may increase the burden of diseases. Malaria, for example, is expected to spread as the mosquitoes that carry it expand their range into warming regions. But climate change might also usher in entirely new diseases, by allowing pathogens to move into new host species.

"We know that species are moving, and when they do, they’re going to have these chances to share viruses,” said Colin Carlson, a biologist at Georgetown University and a co-author of the new study.