Half the animals and plants living in the world’s most nature-rich areas are at risk of dying out from climate change.
Even if goals to limit global warning are met, about a quarter of species could still become extinct, scientists have warned.
Their new study revealed the impact of climate change on important natural regions including the Amazon and the Galapagos Islands.
It found that hitting a target of limiting global warming to no more than 2C above pre-industrial levels could save half the species at risk.
Giant pandas, snow leopards and polar bears are among the animals that could see their territory and food supplies reduced.
The team of researchers looked at the impact of temperature rises and rainfall changes in different climates, affecting almost 80,000 species in 35 natural areas.
Those changes could put pressure on African elephants, which drink large amounts of water, and tigers in Asia which could lose 96% of breeding grounds to rising seas.
If temperature rises are limited to 2C, which would require further action from governments, the impact on wildlife would be lessened but still wide-ranging.
In the Mediterranean, 30% of most species would be at risk of dying out, while more than a third (36%) of plants could vanish.
Affected wildlife could include turtles, as warmer temperatures lead to more eggs hatching as females or failing to hatch altogether, while rising seas and storms can destroy nesting sites.
Lead researcher Professor Rachel Warren from the University of East Anglia said: ‘We studied 80,000 species of plants, mammals, birds, reptiles and amphibians and found that 50% of species could be lost from these areas without climate policy.’
‘However if global warming is limited to 2C above pre-industrial levels this could be reduced to 25%.’
Dr Stephen Cornelius from WWF-UK said: ‘This is a global problem, it shows that across 35 priority places scattered all over the world, all of them over the last 50 years, across all the seasons, have seen temperatures rise.
‘There’s no area that will be unaffected, though there are some that are more vulnerable, and there are some areas that are more resilient than others.’
The study is published in the journal Climatic Change, ahead of Earth Hour, a global environmental event organised by WWF which takes place on March 24.