Climate change to affect the polar bear population

Climate change to affect the polar bear population

25 May 2010

Climate scientists warn that the polar bear population may dwindle in the near future because of global warming.


While studying the impact of rising temperatures in the Arctic on the physiology and behaviour of polar bears, Dr Peter Molnar from Alberta University and his colleagues found that the retreat of the ice cover forces the animals to move to areas where their food sources are scarcer.


Scientists predict that in the western parts of Hudson Bay the mortality rate among polar bears caused by starvation will rise from the current 3%-6% to 28% or even 48% if the duration of the summer season increases from 120 to 180 days.


In addition, female polar bears will have increasingly slimmer chances of finding male partners during the breeding season, which will also negatively affect the polar bear population. The reason for this is that male polar bears look for mates by following in their tracks, while cracks in ice floes on which polar bears live tend to lead to the dispersal of the species: in this case the probability of successful mating will drop from 99% to 72%. These figures were released by RIA Novosti. 


Expert Commentary:

Currently, expert estimates put the number of Chukotka-Alaska polar bears at about 2,000; however, their numbers are falling, according to the International Polar Bear Group. Members of this group believe that the reduction in the number of polar bears may chiefly be ascribed to two factors, which are the shrinkage of the ice cover caused by global warming in polar bear habitats and poaching in Chukotka.


Nobody can exactly predict the extent of the impact that the dwindling habitat has on the polar bear population. We only expect the situation to develop according to the negative scenario, similar to what happened to the well-researched polar bear population inhabiting the western parts of Hudson Bay.


There is another view of the ongoing warming in the Arctic, which is shared by many domestic and foreign scientists. They predict that by 2015 to 2020 the warming in the Arctic will give way to a regular cold spell, which will last until the mid-2030s. Then, another warm cycle will set in.


I would like to refer all those interested in this issue to "Climate Changes in the Ice Cover of the Eurasian Shelf," the second volume of "Scientific Research in the Arctic," a monograph by I. Frolov, Z. Gudkovich, V. Karklin, Ye. Kovalev and V. Smolyanitsky (Nauka Publishers, St Petersburg, 2007. - 158 pages).


It follows from the above that it would be wrong to firmly claim that global warming will last for a long time. However, even if we assume that it will last another few decades, we may expect that in the short term (five to ten years), such warming is unlikely to have a grave negative impact on the polar bear population. The above conclusion comes from the documents of the meeting of the Russian-American scientific polar bear group, which was attended by almost all Russian experts in this area.


As for the polar bear poaching in Chukotka, authorised hunting for marine mammals, such as seals, Pacific walruses, grey and Greenland whales, has fully satisfied the indigenous people's needs for food in recent years.