The effect of climate change on polar bear population

Polar bears are a specialized species, having adapted closely to their environment. The naturally occurring ice cap that covers the Arctic Ocean is their home (Derocher et al. 2004). Their body composition and hunting habits, for example, have molded to the relatively narrow climatic conditions that define the northern polar region (Derocher 2005). The decrease of Arctic sea ice has concerned environmentalists as Earth's global temperature continues to rise. As a result, melting ice caps are displacing polar bears from their natural habitat and stressing their ecological stability. Satellite imaging of the disappearing ice cap, which began in 1979, without doubt, illustrates a drastic geographic change (Stirling and Parkinson 2006). This change, in turn, is forcing polar bears, and other Arctic marine mammals, to move to new territories, which is in itself a stressful adaptation to make. In addition, these new environments are proving to be less than suitable habitats, especially due to a higher human presence.




The threat of extinction, however, is not limited to polar bears. Their main food source, the ringed seal, is also affected by diminishing ice caps because these areas are used for reproduction (Schliebe et al. 2008). Consequently, fewer seals results in less food for the polar bears. The effect of this environmental change is more complex upon closer inspection. Because of the relation between multiple species, including humans, and the overall climate of the Earth, we see that a relatively localized problem should concern a larger audience. In other words, the possible extinction of polar bears may parallel other species' endangerment around the world due to global warming.

Image credit: Arne Nævra 2007