Elizabeth Shogren, NPR
Koda, one of the 3-year-old twin polar bears at the Pittsburgh Zoo, dives for a fish in his special swimming pool.
Koda, one of the 3-year-old twin polar bears at the Pittsburgh Zoo, dives for a fish in his special swimming pool. Elizabeth Shogren, NPR
Elizabeth Shogren, NPR
Henry Kacprzyk, a curator at the Pittsburgh Zoo, says the zoo tries to educate visitors about the risks facing polar bears in the wild.
Henry Kacprzyk, a curator at the Pittsburgh Zoo, says the zoo tries to educate visitors about the risks facing polar bears in the wild. Elizabeth Shogren, NPR
In January 2007, the U.S. Fish and Wildlife Service proposed listing polar bears as an endangered species. The agency is expected to announce a final decision within the next several weeks.
Here's a summary of what recent research says about how polar bears are faring:
- Two-thirds of the world's current polar bear population could be lost by the middle of the century because of shrinking sea ice, according to a 2007 U.S. Geological Survey (USGS) study.
- In 2004, an aerial survey of the northern Alaskan coast documented dead bears floating in the sea. Scientists surmised that the bears drowned because the shrinking sea ice means they have to swim longer distances to shore or between ice slabs. No bear drownings were seen in any other aerial surveys conducted between 1987 and 2003, according to a U.S. Minerals Management Service report.
- The survival rate for cubs that live in the southern Beaufort Sea region in northern Alaska dropped significantly in recent years, according to a 2006 U.S. Geological Survey study.
- Pregnant polar bears in northern Alaska have become much less likely to den on the sea ice. The proportion of dens on sea ice was 62 percent from 1985 to 1994, but dropped to 37 percent in 1998 to 2004. The reason: melting sea ice, according to a 2007 USGS report.
- In the most southerly populations, polar bears already appear to be in trouble. In Canada's West Hudson Bay, the population declined 22 percent between 1987 and 2004, according to a 2007 USGS report.
As global warming shrinks the Arctic sea ice, polar bears' habitat is literally melting. This climate change impact on polar bears — the largest land carnivore — may soon spark the federal government to decide to add them to the endangered species list.
It would be the first time that a species was listed because of climate change, and polar bear experts say the nature of the threat gives polar bear lovers around the globe a chance to pitch in to help save them.
In for Some Bad Times
The only place most people will ever get to see a polar bear is in a zoo. At the Pittsburgh Zoo, you can walk through a glass tunnel to the middle of the bears' swimming pool.
Some people see polar bears as fluffy friends, others as fierce predators. But there's no disputing that the bears are extremely popular, and when visitors stop by, the zoo has handouts at the ready. They explain how reducing energy use and recycling can cut the greenhouse gas pollution that contributes to global warming and benefit polar bears.
"While they're here, we're trying to educate people about the bears and what you can do to help these animals," said Henry Kacprzyk, a zoo curator. "A lot of people don't understand. The Arctic's really in for some bad times."
Scientists predict that two-thirds of the world's polar bears will disappear by the middle of the century. That's because the summertime sea ice is rapidly melting.
Studies show that bears have drowned because the shrinking ice cover means they have to swim longer distances. Cubs in northern Alaska aren't surviving at nearly the rate of recent decades, and more bears are spending summers on land — even denning there. Land isn't the best place for the bears because they're cut off from their main food source. Their ideal habitat is floating slabs of ice, which teem with fish and the bear's favorite meal — seals — according to Rosa Meehan, who heads the marine mammal program for the U.S. Fish and Wildlife Service in Alaska.
More time on land also increases the chance for polar bears to encounter people.
"Polar bears are curious. If there's a new smell, new activity, new noise — it might be something to eat — they'll just go over and investigate," Meehan said.
And that can be deadly for people and bears.
There's also a risk to polar bears from expanding oil production, Meehan added.
Next month, the federal government plans to sell off-shore leases for 30 million acres of the Chukchi Sea, where about one-tenth of the world's polar bears live.
Improving over the Long Term
But scientists say the biggest threat facing the polar bear is global warming.
Unfortunately, for the next few decades, no matter what people do to counteract climate change, the summer sea ice will continue to decline dramatically, Meehan said.
"Even if we all stop driving our cars today, we're not going to have a lot of change in the near term," Meehan said.
But, she says, cutting greenhouse gas pollution now and in the future will improve the polar bears' long-term outlook.
"We want to do everything we can to essentially help the polar bears through this very difficult period, so that polar bears persist and that, when things turn around as a result of society making changes, the polar bears will still be in the environment and be able to take advantage of, hopefully, a rebuilding of the sea ice and a rebuilding of the ice ecosystem," Meehan said.
The U.S. Fish and Wildlife Service had been expected earlier this month to decide whether to list the bears as a threatened species. Now officials say they expect to decide by early February.
Back at the Pittsburgh Zoo, some visitors say they've already gotten the message.
Jim Gessler has been visiting polar bears here since he was a child. Concern about their fate has pushed him to do what he can about climate change.
"I'm turning off lights when I leave the room. I don't have a car anymore," Gessler said.
His daughter, Ann Gessler, 22, has given up meat.
"How much energy it takes to produce a hamburger is really distressing," she said.
She says many people think you have to buy something expensive, such as a hybrid car, to help the environment.
"But if you just make small changes in your lifestyle, that's a lot more beneficial," she added.
But polar bear biologists say that, in addition to individual actions like these, saving the polar bear will require governments around the globe to make major efforts to cut greenhouse gas pollution.