As climate change causes temperatures to rise, animals all over the world are being forced to find new places to live. At the same time, available habitats are shrinking as sea levels rise, storms become more extreme, and human development increases in previously wild areas.
These pressures — and many more — are pushing many species to extinction.
In fact, up to half of the geographical ranges for tens of thousands of animals could be lost by 2100, according to a paper published Friday in the journal Science by researchers at the University of East Anglia in Norfolk, UK, and James Cook University in Australia.
Take Action: Stand Up for the Arctic
The authors based their findings on the current trajectory of global warming, which is on pace to increase global temperatures by 3.2 degrees Celsius compared to pre-industrial levels.
They looked at 31,000 insect species, 8,000 bird species, 1,700 mammal species, 1,800 reptile species, 1,000 amphibian species, and 71,000 species of plants, according to Quartz, and found consistent geographical declines across the animal kingdom.
Insects fared worst in this analysis, with 50% of species losing more than half of their overall ranges if temperatures increased by 3.2 degrees celsius.
An estimated 44% of plants would lose half their overall range, compared to 26% of mammals, birds, reptiles, amphibians, and fish facing the same decline.
Read More: 90% of 'Protected' Land Around the World Is Not Really Protected
The authors argue that this is the worst-case scenario.
The Paris climate agreement, a pact that includes commitments from every country in the world except the United States, aims to keep global temperatures from rising above 2 degrees Celsius compared to pre-industrial levels.
If this goal is achieved, then only 16% of plants, and 8% of insects, mammals, birds, reptiles, amphibians, and fish would lose more than 50% of their range by 2100.
The authors urge countries to go even further, by keeping global temperatures from rising more than 1.5 degrees Celsius, which would spare an even greater number of animals.
Read More: Nat Geo's Surprising New Cover Shows the Ongoing Perils of Plastic Pollution
In that scenario, 6% of insects, 8% of plants, and 4% of mammals, birds, reptiles, amphibians, and fish would see their habitats halved, according to the report.
Of course, either outcome still means thousands of animal species would be catastrophically harmed.
Other studies have proclaimed that the world is currently experiencing its sixth mass wave of extinction and billions of local animal populations will be lost.
In this era of climate change, the simple truth is that an unharmed species is the exception to the rule.
“The resulting biological annihilation obviously will have serious ecological, economic and social consequences,” the authors of a report on the sixth extinction wrote. “Humanity will eventually pay a very high price for the decimation of the only assemblage of life that we know of in the universe.”
Global Citizen campaigns on the United Nations’ Global Goals, which call on countries to protect biodiversity. You can take action on this issue here.