As Ice Melts, Can Polar Bears Survive? (NYT)

Regarding ''Bearing Up'' (Op-Ed, Jan. 5)

In contrast to Gov. Sarah Palin's claims, the Alaskan polar bears are not thriving. The center's director, Dr. Eric Chivian writes that rising temperatures and melting glaciers have made it incredibly difficult for polar bears to hunt seals, their main food. In addition, these predators are accumulating pollutants that are disrupting their reproductive systems.

The Arctic is home to a unique ecosystem that has adapted to harsh environmental conditions over millions of years. Polar bears are one of the iconic animals of this region, and they rely on sea ice for hunting, mating, and raising their young. However, as the Arctic warms due to climate change, the sea ice is melting at an unprecedented rate. This poses a grave threat to the survival of polar bears, as they may be unable to adapt quickly enough to the changing conditions.

The Importance of Sea Ice for Polar Bears

Polar bears are highly specialized predators that rely on sea ice to hunt for their primary prey, ringed and bearded seals. The ice provides a platform from which they can stalk and ambush their prey, as well as a resting place between hunts. In addition, the sea ice is crucial for the breeding and rearing of young polar bears, as females construct dens on the ice to give birth and raise their cubs.

However, the Arctic sea ice is disappearing at a rapid rate. According to the National Snow and Ice Data Center, the extent of Arctic sea ice in September, when it reaches its minimum each year, has declined by an average of 13.1 percent per decade since 1979. This trend is expected to continue, and some projections suggest that the Arctic could be ice-free in summer as early as 2040.

The Impact of Climate Change on Polar Bears

The decline in Arctic sea ice has had a significant impact on the polar bear population. As their hunting grounds disappear, polar bears are forced to swim longer distances to find food. This is both energetically costly and dangerous, as they may not find enough prey to sustain themselves or drown if they become exhausted. Moreover, the longer swimming distances increase the risk of polar bears encountering oil spills or shipping traffic, which can be fatal.

In addition to the direct impacts on hunting and travel, the loss of sea ice also affects polar bear reproduction. Female polar bears need the ice to den and raise their cubs, and the lack of suitable ice can result in lower cub survival rates. In some areas, the ice is breaking up earlier in the spring, causing the bears to come ashore before they have had a chance to build up sufficient fat reserves. This can lead to starvation and reduced reproduction rates.

Can Polar Bears Survive as the Arctic Warms?

Despite the significant challenges facing polar bears in a changing climate, there is still hope for their survival. Researchers are studying the adaptability of polar bears and their potential to switch to alternative prey, such as fish or land mammals, as the sea ice disappears. Some polar bears have already been observed hunting on land or scavenging carcasses, suggesting that they may be more flexible than previously thought.

In addition, conservation measures are being implemented to protect polar bear populations. The International Union for Conservation of Nature (IUCN) lists polar bears as a vulnerable species and recommends that their habitat be protected. The United States has designated critical habitat areas for polar bears in Alaska, and Canada has established a polar bear conservation strategy. Moreover, international agreements, such as the Paris.

Aaron Bernstein, MD, MPH

Aaron Bernstein is the Interim Director of The Center for Climate, Health, and the Global Environment, a pediatrician at Boston Children’s Hospital, and an Assistant Professor of Pediatrics.

Leave a Comment

Scroll to Top