If greenhouse gas emission rates do not slow down, polar bears may not be around much longer. A report out this week from the U.S. Geological Survey stated that updated scientific models show a potential "great decrease" in the world's population of polar bears, specifically in Alaska, the only place in the United States where they live.

The causes of imminent danger facing police bears are linked to the use of greenhouse gases and the burning of fossil fuels, according to the Associated Press. Both have led to melting of polar ice caps, which is vital to the animal's habitat.

Polar bears eat sea ice, as well as seals. Seasonally, when it gets warmer and sea ice retreats, the animals make the dangerous move to land. The species has not been able to adapt to living off of land-based food, and the continuing loss of sea ice is what makes the situation particularly grave. 

With less space to live and less ice to consume, scientists predict massive polar bear population decline in the near future.

The scientists in the study used two different scenarios, one where greenhouse gas emissions decline over the years and one where they steadily increase on the current path, to see if there is hope that something can be done to help the animals.

Both projections went to the year 2100 and in both scenarios, the population of polar bears in the Alaska, Russia and Norway group (currently estimated at 8,500) will be in grave danger and near extinction between 2025 and 2030, Todd Atwood, an Alaska-based USGS research wildlife biologist and lead author of the study, said. The scientists could not estimate an exact number of how many polar bear will be affected, but believe it while be a large part of the population.

"That's not to say that we'll lose polar bears completely out of the area, but we think that they'll be at a greatly decreased distribution than what they currently are," Atwood said.

The Polar bear population near Canada and Greenland may see a similar decrease, but closer to the year 2050, the study said. The "safest" region for polar bears is in the northern part of the Canadian arctic, where the model scientists used only showed drastic population decrease under worst-case scenarios.

The animal has been endangered since 2008. It is the only species that is on the list directly because of climate change.

"Polar bears are in big trouble," said Rebecca Noblin, Alaska director for the Center for Biological Diversity. "There are other steps we can take to slow the decline of polar bears, but in the long run, the only way to save polar bears in the Arctic is to reduce greenhouse gas emissions."