The last 15 years, have brought the 15 lowest sea ice extent. Being steadily decreasing, it could lead to polar bears no longer existing after 2100.
All animals that are dependent on ice are in danger, especially polar bears. The cause is in the steady decrease of Arctic sea ice. Since satellite records began in 1979, it has been shrinking year after year. According to a new study by Columbia University's Lamont-Doherty Earth Observatory, the consequence will be that polar bears could be extinct by the end of the century, or by 2100.
Polar bears at high risk of extinction
Scientists previously believed that the "Last Ice Area," which is a region containing the oldest and thickest Arctic ice, would last for decades. In reality, things have turned out differently than predicted: sea ice in the area will thin dramatically by 2050, in both the most positive and most negative scenarios. The most optimistic scenario is that a portion of the ice will survive, while in the most pessimistic one, the summer ice could disappear by 2100, along with polar bears and seals. According to the National Snow and Ice Data Center (NSIDC), in the last 15 years, the 15 lowest sea ice extent has been observed during all satellite recordings.
Polar bears could interbreed with grizzlies
Polar bears feed predominantly on seals and the disappearance of the latter would lead to the disappearance of the former as well. For this reason, the reduction of Arctic sea ice would lead to the extinction of both species. A 2015 study published in the journal Frontiers in Ecology and the Environment had analyzed the bears' diet composed of seabird eggs and caribou, but the results showed that the calories obtained from this diet are not enough to balance those that bears burn during hunting.
The species will be forced to adapt to a new habitat and, in order to survive, polar bears could interbreed with grizzlies giving rise to a new species: the grizzly bear. As temperatures rise, polar bears move further south in search of food, while grizzlies move north to go to cooler places. As they come into contact, they sometimes mate in what scholars have called "opportunistic unions."
Climate change is endangering more and more animal species, the International Union for Conservation of Nature recently released its red list of endangered wildlife. Instead, a study has identified that animals are changing shape due to rising temperatures in their natural habitats.
Stefania Bernardini