Scientists warn that climate change could wipe out more than half of these beloved animals

It’s bad enough that climate change is ruining the dream of a white Christmas for many people, as warming makes snow in some regions less likely.

Now, apparently, it’s coming for reindeer, too.

Reindeer aren’t just creatures of Christmas myth but real animals — a kind of deer that live in the Arctic, from northern Europe and Russia to North America, where they’re commonly known as caribou. These animals are remarkably adapted to cold weather, sporting thick fur, a snout that warms the air they take in, and uniquely structured hooves that help them shovel snow to find food, such as lichen. But they’ve also survived bouts of Arctic warming that occurred thousands of years ago, thanks to their ability to travel long distances in search of colder habitats.

These adaptations are, however, no match for modern climate change. The Arctic is warming quickly from a higher baseline temperature compared to natural fluctuations in the distant past.

Over the last few decades, wild Arctic reindeer populations have declined by about two-thirds, from 5.5 million to around 1.9 million, largely due to warming, according to previous research. Rising temperatures can affect reindeer health directly — causing the animals to overheat and get sick — and indirectly by limiting their supply of food.

Now, it’s clear those declines will likely continue. A new study in the journal Science Advances found that if the world doesn’t quickly rein in greenhouse gas emissions, the global wild reindeer population, including caribou, could plummet by nearly 60 percent by the end of the century. Those declines will be far more severe in North America, where they could exceed 80 percent, according to the study’s models, which reconstructed 21,000 years of reindeer population data using fossil records, DNA, and other data sources. That’s because North America is expected to lose more habitat that can support reindeer to warming than elsewhere, said Damien Fordham, a study author and researcher at the University of Adelaide.

Even under a more modest emissions scenario — in which countries cut back what they spew into the atmosphere — the study projects steep population declines. You can see these results in the chart below, which shows projected declines based on a high and moderate emissions scenario, respectively.

“These results are absolutely concerning,” said Jennifer Watts, Arctic program director at the Woodwell Climate Research Center, a nonprofit research organization, who was not involved in the new study. “Given how quickly and severely the Arctic is warming at present, the results from this study are not overly surprising, and should serve as yet another wake-up call for humans to curtail anthropogenic drivers of climate warming.”

The study offers yet another example of how climate change is threatening biodiversity and how those threats in turn affect humans. Reindeer are not only a critical food source for some Arctic Indigenous communities — like Alaskan Natives and the Inuit people of North America — but also a cornerstone of their culture, similar to salmon or wolves for some tribal nations in other parts of the US. If major polluting nations, like the US, China, and India don’t curtail their emissions, it could further endanger the food sovereignty of those communities.

Beyond their direct impact on human well-being, reindeer also shape the tundra ecosystems — quite literally making them what they are — by limiting the growth of trees and shrubs, spreading seeds, and fertilizing the soil.

“We should care about the fate of reindeer and caribou with the same concern we give to the fate of polar bears and other Arctic animals,” Watts told Vox. “The well-being of entire ecosystems and humans living across the Arctic depend on their survival.”