Polar bears need sea ice to hunt prey and as global temperatures increase that ice melts, said Conrad Savy, a biodiversity analyst for Conservation International.

The question is whether this warming is induced by human activity, or is part of a natural process or a combination of the two, said Alan Arbogast, an MSU associate professor of geography.

There are two kinds of Arctic ice: Sea ice and winter, or annual, Savy said. Scientists have been measuring the ice since the 1970s and every year there has been a little less of both types because of melting, he said.

“For polar bears, sea ice is critical. During the summer months they go out onto the ice to hunt seals,” Savy said. “Up to half of that habitat could be lost in the next 100 years.”

Polar bears are the poster animal for climate change, because they’re a high-profile animal and they’re affected greatly by global warming, Arbogast said.

Arbogast said he doesn’t know whether people will be willing to make sacrifices to save the animal.

There are up to 25,000 polar bears alive today, Savy said.

“I don’t believe in using listings as a political tool,” said Jim Harding, an MSU zoology professor and outreach specialist of wildlife.

“I believe in listing animals if it’s biologically justified — that’s the way the law is written, you just have to go back to the original (U.S.) Endangered Species Act.”

Since it passed in 1973, the endangered species act has provided for the conservation of ecosystems, including protecting threatened and endangered species of fish, wildlife and plants, according to the U.S. Fish and Wildlife Service.

Savy said he doesn’t know whether the polar bear’s endangerment will push for environmental policy change.

In his classes Arbogast said he often asks students how they feel about the possibility of polar bears going extinct and most of them are upset by it, but when he asks who among them is willing to make changes to protect the animal, their concern for the problem lessens.

“It’s pretty well documented that people have a very difficult time anticipating the future and making decisions right now that will help problems 10 years from now,” Arbogast said.

Polar bears are an important part of the food chain, so even if some people don’t care about them, Arbogast said he questions at what point the collapse of the ecosystem will affect humans.

“You’re 20, 21 — and by the time you’re 50 (the earth is) going to be a very different place,” he said.