Polar bears live only in the Arctic, and they depend entirely on the pack ice—the frozen surface of the Arctic Ocean—as a platform to breed, raise their young, to hunt and to travel. Scientists are predicting an ice-free Arctic Ocean in summer by as early as 2050, which could quite possibly spell doom for this magnificent creature.

When heaven melts away

In just a few short decades, Arctic sea ice has lost thickness, melted faster in spring and re-formed later in fall. As a result, the extent of the Arctic sea ice has already shrunk by 15-20 percent in the past 30 years, and an area the size of Arizona and Texas combined has melted away. The thick multi-year ice essential to polar bears has been shrinking 8 to 10 percent per decade. In recent years, not only has Arctic sea ice been experiencing unprecedented melt in summer, but winter freeze-up is no longer fully compensating for that summer melt, pointing to a long-term, steady decline in Arctic sea ice year-round.

Scientists can already see the impacts of global warming on polar bear populations. The most dramatic so far may be in western Hudson Bay, Canada, the southern edge of the polar bears’ range. Here, sea ice has been breaking up three weeks earlier than it did decades ago. Bears must spend an extra month on shore fasting, waiting for ice to re-form in the fall before they can go back out onto the ice to hunt seals, their primary food source. As a result, the population has plunged 13 percent in 10 years, from 1,100 in 1995 to fewer than 950 in 2004. Scientists have also documented thinner bears, lower female reproductive rates, and reduced juvenile survival in this population of bears.

Perhaps most astonishingly, in December of 2005 the US government released a study showing that polar bear drownings off the north coast of Alaska, once rare, have been happening with greater frequency. Reduced sea ice means polar bears have to swim greater distances than before, which puts them at greater risk of drowning.

But the news isn’t all bad. There is hope for the world’s polar bears. In December, Greenpeace joined with two other environmental groups to force the Bush administration to list the polar bear under the Endangered Species Act. If successful, the lawsuit will force the Bush Administration to protect polar bears and their habitat—and the only way to protect polar bears from the disappearance of their sea ice habitat is by reducing emissions of global warming pollution and implementing cleaner forms of energy such as solar and wind.