PARIS: Polar bear numbers could drop a third by mid-century, according to the first systematic assessment, released Wednesday, of how dwindling Arctic sea ice affects the world’s largest bear.
There is a 70 percent chance that the global polar bear population — estimated at 26,000 — will decline by more than 30 percent over the next 35 years, a period corresponding to three generations, the study found.
Other assessments have reached similar conclusions, notably a recent review by the International Union for the Conservation of Nature (IUCN), which tracks endangered species on its Red List.
The IUCN classified the sea-faring polar bear — a.k.a. Ursus maritimus — as “vulnerable”, or at high risk of extinction in the wild.
But the new study, published in the Royal Society’s Biology Letters, is the most comprehensive to date, combining 35 years of satellite data on Arctic sea ice with all known shifts in 19 distinct polar bears groupings scattered across four ecological zones in the Arctic.
“Polar bears depend on sea ice for most aspects of their life history,” the study notes.
Most importantly, they use it as a floating platform to hunt seals, which can outswim them in open water.
Researchers led by Eric Regehr of the US Fish and Wildlife Service in Anchorage, Alaska projected three population scenarios out to mid-century, and all of them were bad news for the snow-white carnivores.
The first assumed a proportional decline in sea ice and polar bears.
