Climate Education

Dwindling ice is forcing polar bears to make longer, more dangerous swims

Polar bears are furry, white, and beautiful. Unfortunately, they are also in danger. Melting arctic ice forces them to swim for more than a week without rest in search of slabs of sea ice that are large enough to live on. Scientists, after years of observation and research, found that as arctic sea ice melts, polar bears migrate toward the icy Canadian Arctic Archipelago. Polar bears desperately need to adapt to a warmer environment due to the lack of sea ice in the Arctic Ocean brought about by climate change. The number of polar bears making long distance swims to migrate is directly proportional to the loss of sea ice, the researchers explained. Polar bears prefer to live on Arctic sea ice, although they sometimes swim between ice floes and land. Many observations prove that polar bears are good swimmers, but they are not comfortably able to swimming long distances. After all, they can only paddle about 1.25 miles per hour. Finding a new slab of sea ice to live on takes them an entire day of swimming. In August and October of 2008, scientists tracked an adult female polar bear in the Beaufort Sea that had swam a total of 687 kilometers (426 miles) over 9 days and then intermittently swam and walked on the sea ice surface an additional 1,800 kilometers (1,118 miles). This polar bear was unable to stop for food or rest until she got to a new slab of sea ice large enough for her to live. Scientists calculated the body mass lost according to her movement rate, hourly activity, and subcutaneous and body temperature of swimming, the female polar bear lost 22% of her body mass. But worse, she lost her year-old cub. Polar bear migration is related to climate change. The phenomenon of polar bears swimming to a new slab of sea ice is influenced by the changing sea ice dynamics. Environmental change in the Arctic is affecting Arctic animals. Polar bears need sea ice habitat on the continental slab, so that they can hunt foods like seals. Observation had shown that as seasonal periods of open water extend, the frequency of swims by polar bears will increase. To better understand the issues and the danger facing polar bears, we first need to understand climate change. Climate change is the rise in average temperatures on Earth. The temperature of the Earth is regulated by the atmosphere trapping the sun’s heat. Scientific evidence shows that climate change is due primarily to human activity through the use of fossil fuels. As the Earth’s temperatures rises, sea ice melts and the existence of polar bears becomes increasingly at risk.