The polar bear, with its ice habitat in decline, has become a symbol of the effects of global warming. But according to some people who deny or downplay climate change, the species is thriving. For example, a viral tweet and its subsequent thread claimed that the global population of polar bears has “never been higher.”
It’s a claim that’s been repeated frequently over the years. A Wall Street Journal article from 15 years ago took exception to the Bush administration recommending polar bears be listed as “threatened” under the Endangered Species Act, claiming that it was unnecessary because the polar bear population was higher than it had ever been before. An article by the Foundation for Economic Education in 2019 shared similar data to argue that polar bears are thriving.
Other popular tweets have likewise claimed that the global polar bear population is "thriving."
Are claims that polar bears are “thriving” because their population is “increasing” true?
John Whiteman, Ph.D., a biological sciences professor at Old Dominion University and chief research scientist for Polar Bears International
Andrew Derocher, Ph.D., a biological sciences professor at the University of Alberta and a scientist in the International Union for the Conservation of Nature’s (IUCN) Polar Bear Specialist Group
Claims that polar bears are thriving, as proven by a rising population, are misleading. Polar bear numbers did rise in the late 20th century after governments implemented hunting restrictions. But they aren’t currently increasing in number, and their future remains in peril.
WHAT WE FOUND
Scientists don’t know the exact number of polar bears in existence, largely because many of them live in places difficult to reach. Instead, they estimate a global population and update that estimate whenever their data improves.
Even with limited data, scientists are confident that there are more polar bears now than there were 50 years ago, when polar bears were victims of overhunting. But now that the population has leveled off, they do not believe the number is still growing today.
Some clusters of polar bears are in decline, some are stable, some are increasing and most lack enough data to draw any conclusions.
“It is both simultaneously true to point to part of recent history and say there's a conservation success story here, and that should rightfully be celebrated, and to also say there's an immediate existential threat to the entire species right now,” said John Whiteman, chief research scientist for Polar Bears International.
But even if scientists did have all the data, and even if that data did show a present-day growth in the polar bear population, polar bears wouldn’t be “thriving.” The global polar bear population would still be vulnerable to decline as sea-ice loss continued in the Arctic.
“It's a very different threat imposed by climate change going forward as compared to [hunting] going backwards,” said Andrew Derocher, a scientist in the International Union for the Conservation of Nature’s (IUCN) Polar Bear Specialist Group and professor at the University of Alberta.
Using VERIFIED sources, we break down the state of the polar bear population in the past, the recent status of the polar bear population and what’s on the horizon for the species.
Polar bears’ past — late 20th century
Back in the 1960s, polar bears were on the verge of extinction thanks to overhunting. Although the exact number of polar bears in the wild was unknown and estimates were therefore even less precise than they are today — Derocher said that modern surveying techniques weren’t developed until the 1970s and 1980s — the estimates from the time put the global polar bear population at 5,000 to 10,000.
In 1973, there was an agreement between the five Arctic countries where polar bears live — Canada, the Soviet Union, Norway, Greenland (Denmark) and the U.S. — to make local polar bear hunting sustainable.
“As that hunting pressure was reduced and managed more effectively around the Arctic, the number [of polar bears] increased,” Whiteman said. “And so between I would say the 60s and the 90s, polar bears were absolutely a conservation success story.”
But that success story was three decades ago, and biologists don’t believe polar bears are still in their post-hunting regulation population boom.
“I think that most populations that were overharvested have already sort of plateaued at whatever level they're going to be at,” Derocher explained.
Polar bears’ present — From 2000 to today
Even today, the exact number of polar bears around the globe is unknown, but estimates are at least much better than they were just 10 years ago.
Instead of looking at polar bears as a single global population, today’s researchers track polar bears in 19 distinct sub-populations, each within a separate region of the Arctic. These sub-populations all face unique conditions that affect polar bears differently, Derocher said. So because scientists research and track each region of polar bears individually, they can get insight into which parts of the Arctic polar bears are doing the best, and which parts they’re doing the worst.
Of the 19 sub-populations, 10 lack enough data for scientists to determine population trends, according to a map from Polar Bears International. Three populations are in decline, four are stable and two are on the rise.
The 10 data-deficient sub-populations all live in regions with little infrastructure and particularly harsh conditions, such as the Siberian coast and east Greenland. Derocher said scientists still try to make their best guess at the polar bear numbers in these regions, often using the health of the regional sea ice as indicators. But it’s still the equivalent of “hand waving,” according to Whiteman.
Still, scientists attempt to put together a global polar bear population. The World Wildlife Fund (WWF) says IUCN scientists currently estimate there are 22,000 to 31,000 polar bears worldwide, or approximately 26,000.
That's higher than the 20,000 to 25,000 polar bears the IUCN estimated about 10 years ago. The change doesn’t reflect an increase in the number of polar bears, the WWF explains. Instead, it’s the result of recent improvements to surveying some of the sub-populations of polar bears, particularly in data-deficient regions.
Based on the data they do have, both Whiteman and Derocher estimate that the global polar bear population is currently in a slight decline, or stable at best. But proclamations that polar bears are definitely increasing or definitely declining in total number should be treated with skepticism, at least for now, Whiteman said.
Polar bears’ future — Over the next century
Both Whiteman and Derocher said past and current trends in the global polar bear population have no indication on how polar bears will fare in the future.
“We can predict with quite high likelihood that there's going to be a major decline in the range of polar bears, which means that a lot of these sub-populations will be extirpated, which is a fancy word for local extinction,” Derocher said. “As a species, though, we do not anticipate that there's a very high likelihood of extinction within [the next three generations, or 33 years]. And even some of the work in my research group suggests that the likelihood of extinction before the end of the century is quite low as well.”
His prediction has everything to do with sea ice.
Whiteman explained that polar bears are highly specialized for life on sea ice. Their teeth are designed to eat fewer plants and more meat, particularly seals, than other bears. They have curved claws to grab slippery prey and have traction on ice. They’re massive; polar bears are about as heavy as the largest brown bears.
“Can polar bears go on shore and survive for a couple of months? Yes, and they do that in some parts of their range right now as part of their natural cycle, for sure,” Whiteman said. “But could they fully transition to being shore-based animals? Not a chance; their best hope would be to evolve back into brown bears if they're going to do that.”
Scientists can see there has been greater and greater Arctic sea ice melt over the past couple of decades, and so they’re confident that continued melt will mean fewer and fewer polar bears. But, at least in the short term, they know that some polar bear sub-populations won’t struggle at all.
Remember those two sub-populations on the rise? They live in regions with nearly 100% sea ice cover year-round. Whiteman said that those conditions are unfavorable even for polar bears, which need breaks in the ice if seals are going to surface for air and make themselves vulnerable to hungry bears.
So while polar bears in regions without much sea ice will suffer first and decline most rapidly as what little ice they have melts, Whiteman said that polar bears in these ice-dense regions will actually benefit from improved habitat quality, at least at first. Polar bear biologists actually predicted this would happen, Whiteman said.
But eventually, if sea ice loss continues to such an extreme that the icier regions are left with barely any sea ice at all, then the polar bears there will also suffer.