As the emission of greenhouse gases due to anthropogenic activities remains unabated, the temperature of our planet continues to soar. The global warming repercussions are being felt all over the world, however, the effects are more dramatic and drastic at the poles, especially at the Arctic; the ice on the Arctic regions have been melting at a faster rate than at the Antarctic. The air and water temperature over the Arctic have gone up in recent years, and this change in weather patterns or climate change, has put its ecosystem at risk and now many species stand closer to massive decline or, in the worst-case scenario, to mass extinction, in decades not far away from us. From losing their habitats, unnatural migration in search of food to changes in the reproductive life cycles–global warming is decimating wildlife population significantly. Fondly known as, the Kings of Arctic, the prodigious, hyper-carnivorous Polar bears are one such group who are on the brink of starvation with increasing sea-ice cover loss due to rising temperature.
In the Arctic circle, polar bears have been a popular subject for researchers and scientists for decades. With a population of over 25,000 worldwide, polar bears are found in Canada, the United States, Russia, Greenland and Norway. There are approximately 19 groups or sub-populations of Polar bears, of which, some of these groups are on the decline. In some regions, the population has plummeted worse than others. An estimation says that in the years between 2000 and 2010, 40 per cent of the population declined in Beaufort sea regions, the frozen sea north of Alaska. While there is still a lack of clarity regarding what may have caused this sharp decline in some particular regions, wildlife biologists and climatologists have not ruled out the possibility of climate change caused by global warming.
Polar bears, the largest land-based carnivores, rely heavily on seals–ringed and bearded seals– for over 90 per cent of their diet. Ideally, the main hunting seasons are spring and summers. However, owing to irregularities in the thawing sea-ice cover and deformity of the ice, seals which normally come out from their breathing holes are becoming inaccessible to the bears. As a result, the bears now have to starve for a longer than their natural fasting period. Also, the feeding period of the bears has reduced by three weeks, as the ice cover is now breaking earlier in the spring and forming later in the fall. According to a study, sea ice has been decreasing 14 per cent each year, that means, these polar bears now have to travel further and further to find their favourite prey and in the absence of enough food, they have to live off the fat reserve from earlier kill in the previous season. This has negatively impacted their health; there has been a considerable weight loss in female polar bears.
Global warming has not only starved these animals, but it has also threatened the life of their cubs. Mother bears need deep snowbanks–at least with a depth of 2 metres–to dig dens for their cubs where they spend months nursing and nurturing these blind, hair-less, tiny cubs. Rising temperature and declining snow levels could damage these dens and they can get deprived of a safe place to grow. While there is still a large controversy around the impacts of global warming on the declining population of polar bears, recent findings on the life cycle of these bears have enough evidence that if the global warming remains unmitigated, we might start losing their other sub-populations too in future!