Polar bears have been the poster child for scientists concerned about climate change. The arctic species is strikingly beautiful and instantly recognizable; they’re also in serious trouble.

The root of the problem is that rising temperatures are reducing the amount of sea ice that exists from Russia to Norway and from Canada to Alaska. Polar bears depend on that ice to hunt. Without it, they aren’t able to eat enough, and they’ll die.

Biologist Andrew Derocher is unequivocal about the problem. He told Upworthy, “We can quibble amongst ourselves as scientists, but the overwhelming scientific consensus is absolutely clear: Polar bears are in trouble.”

There is little doubt among scientists that climate change will be disastrous for many species. However, polar bears offer a concrete look at how a species can decline when its environmental conditions change.

Derocher tracks how sea ice is disappearing and what effects this has on the bears. He has observed the species becoming smaller in size, reproducing less frequently, and young and old bears dying more frequently. 

The biologist also shares positive news, like a survey showing polar bears doing well in the Chukchi Sea region in between Alaska and Russia. Even that good news is tinged with concern. The area has seen a steady decline in sea ice over the past five years with all signs pointing towards continued losses.

Derocher has studied polar bears since the early ’80s. He has tracked and studied thousands of bears and has seen firsthand how reductions in sea ice have affected the species.

Since polar bears do most of their hunting on ice, their fat stores must last them through the ice-free days. As the ice recedes, they have to travel farther just to find ice to hunt on. This traveling burns valuable calories that would normally help get them through the ice-free times. 

When female bears don’t store enough calories, they can’t produce enough milk for their cubs. This leads to unusually high cub-mortality rates.

Reduced sea ice means that some areas will likely lose their entire polar bear population. It may not be too late to save the species if the planet can slow or reverse its warming trend.

Derocher applauds the efforts of some businesses to become more sustainable and slow climate change. He encourages the public to support these businesses with their wallets and reward them for reducing their carbon footprints.

He believes that we can save polar bears with a concerted effort to preserve sea ice. However, doing so will take a major effort by all countries on the planet. He says simply, “It’s got to change. The way we live on this planet has got to change.”