Scientists looked at nearly 34,000 animal species and found that by 2050, heat waves alone could impact almost three-quarters of their habitats.
Wildfires, droughts, and floods are also major risks, especially in places such as the Amazon, Africa, and Southeast Asia.
The team highlighted how events such as Australia's 2019-20 heat wave killed more than 72,000 flying foxes as a warning sign for what is to come.
They are urging faster action on climate change and more research into how animals can adapt.