We see evidence of the kill first: a shockingly broad spread of scarlet, probably the blood of a ringed seal, on snow-covered sea ice. Then the polar bear appears. She’s big, maybe 500 pounds, trailed by a single cub. They’ve just jumped into a lead—a long fissure of open water in the frozen sea. In seconds they’re out of the water again, running across the ice, spooked by the approach of our helicopter. Prolonged running can harm polar bears: Fat and fur insulate them so well they risk overheating. François Létourneau-Cloutier, our 33-year-old Québécois pilot, takes us higher, and the mother and cub slow to an amble.
After following them for several minutes, Létourneau-Cloutier sets the helicopter gently onto the ice a few hundred feet away and cuts the engine. The mother rises on her hind legs, assessing our 35-foot-long flying machine with the unruffled gaze of the Arctic’s top predator; the cub remains on all fours behind her. For a few timeless moments we savor the scene—bears against an otherwise empty immensity of snow and ice, countless shallow pools of meltwater reflecting a high summer sun ringed by faint halos of red and blue. Then, with a frenzied whine, the helicopter’s rotor blades break the spell, and we lift off, veering southwest toward our campsite on the northernmost tip of Baffin Island, Canada, about 700 miles north of Hudson Bay.
Within a few decades such vistas are unlikely to exist, at least not here, during summer. As the planet heats up, the summer sea ice and all the superbly adapted life it supports—the bears, the seals, the walruses, the whales, the Arctic cod, the crustaceans, the ice algae—may well vanish around Baffin. As we fly over the vast frozen expanse, it almost strains belief to think that we’re witnessing—and with the rest of humanity, helping to cause—its demise. In the 1980s satellite data showed that Arctic sea ice extended on average across nearly three million square miles at the end of summer. Since then more than a million square miles has been lost—an area roughly the size of Alaska, Texas, and California combined.