The big question is when the Arctic will “look like a blue ocean,” said Mark Serreze, director of the National Snow and Ice Data Center. So, no matter what, the Earth will soon see a summer with less than 1 million square kilometers of sea ice scattered in tiny bits across the Arctic. The warming already in the oceans and in the air is committed - like a freight train in motion. “That’s like taking a sledgehammer to the climate system and doing something huge about it.” “That’s something human civilization has never known,” Abdalati said. Many other experts agree with her.įormer NASA chief scientist Waleed Abdalati, now a top University of Colorado environmental researcher, is one of them. Julienne Stroeve, a University of Manitoba researcher, says summers without sea ice are inevitable. The more the sea ice shrinks in the summer, the thinner the ice is overall, because the ice is weaker first-year ice. How much it shrinks is where global warming kicks in, scientists say. She asks: “Do we really want to be the generation that saw the end of the ability of something as majestic as the polar bear to survive?” The state of sea iceĪrctic sea ice - frozen ocean water - shrinks during the summer as it gets warmer, then forms again in the long winter.

United Nations Environment Program head Inger Andersen used to lead the International Union for the Conservation of Nature, which monitors and classifies species in trouble. Scientists and advocates point to polar bears, marked as “threatened” on the endangered species list, as the white-hot warning signal for the rest of the planet - “the canary in the cryosphere.” As world leaders meet in Glasgow, Scotland, to try to ramp up efforts to curb climate change, the specter of polar bears looms over them. “There’s just something special about polar bears.” “They have just always been a revered species by people, going back hundreds and hundreds of years,” said longtime government polar bear researcher Steve Amstrup, now chief scientist for Polar Bear International. But where it lives, where it hunts, where it eats - it’s disappearing underfoot in the crucial summertime. In the harsh and unforgiving Arctic, where frigid cold is not just a way of life but a necessity, the polar bear stands out. Majestic, increasingly hungry and at risk of disappearing, the polar bear is dependent on something melting away on our warming planet: sea ice. (BJ Kirschhoffer/Polar Bears International via AP) Arctic sea ice - frozen ocean water - shrinks during the summer as it gets warmer, then forms again in the long winter. This June 2018 photo provided by Polar Bears International shows polar bear standing on sea ice north of Svalbard, Norway.

The land of always winter