One Critical Reason to Cut Global Warming Pollution Now: The Amazing Polar Bear

This week I'm out on the tundra in Wapusk National Park in Manitoba, Canada, on the shores of western Hudson Bay, for educational webcasting and blogging with Polar Bears International . Polar bears gather in this area every fall, waiting for the bay to freeze so that they can go back out onto the ice to hunt seals, their primary food. We watch the bears from a special teched-out vehicle called a "tundra buggy," and during the day you can often see the same bears we're watching out the window on the live polar bear cam .

There was a time today -- standing out on the back deck of the buggy, when two large males came quite close to us -- that I was so mesmerized I couldn't even take a photo. Instead I just lost myself in the sound of their footsteps, the rhythm of their breathing and the wonder of their massive bodies, so magnificently adapted for life in the frigid North. Several males were play-fighting, wrestling and rolling on the ground, looking fierce and majestic one moment and teddy-bear cute the next. To complete the picture, a mother polar bear and her cub also passed by. It's hard to describe the magic of these animals.

The other night the just-past-full moon rose in yellow glory over the rippling open waters of Hudson Bay. It was a lovely sight but also disturbing, because even though it's mid-November there is virtually no ice on the bay. And polar bears need that ice to live. As the climate warms, the ice-free season here in western Hudson Bay has gotten longer, and the bears now have to contend with ever-increasing periods of fasting on land and shorter periods out on the ice to catch the seals they need to survive. The bears here are smaller and lighter than they used to be, fewer cubs survive, and the population is declining in numbers. Increasingly, individual bears are starving as the Arctic rapidly warms. This population, among the southernmost of the world's polar bear populations, is on a course to be the first victim of global warming. What's happening here will be the fate of all polar bears if we don't rapidly reduce greenhouse emissions.

This week we've also seen several very thin bears. Polar bears fasting on land lose about two pounds per day, and it's not clear how much longer it will be before the ice freezes and bears here can go back out onto the ice to hunt seals. It's painful to see their condition, but it's not surprising: Scientists have long predicted the situation now playing out. I fervently hope the ice will come soon for the sake of these bears, but ultimately the only way to prevent more suffering and save the species from extinction is to get serious about cutting greenhouse pollution . Of course, polar bears are only one of so many reasons we need to act. But it always strikes me deeply, when I'm watching these beautiful creatures in their northern home, what a compelling reason they are all by themselves. And it just so happens that the deep and rapid emission reductions needed to save the bears are the same reductions necessary to avoid the most catastrophic outcomes for the rest of the world too.