Sunday, 30 September 2012

Polar Bears against the Global Warming


Global warming is the rise in the average temperature of Earth's atmosphere and oceans since the late 19th century and still in continuation. Since the early 20th century, Earth's mean surface temperature has increased by about 0.8 °C (1.4 °F), with about two-thirds of the increase occurring since 1980. Warming is expected to be strongest in the Arctic and would be associated with the continuing retreat of glaciers, permafrost and sea ice.


In relation with the issue of global warming, Greenland Post issued the commemorative stamps on a nicely designed miniature sheet  which features the damaging effects of global warming in mind and how this is causing major problems to the population of Polar Bears in Greenland and the surrounding areas. The miniature sheet comprises of two postage stamps which released on the first of May 2010.


Polar bears hunt seals from a platform of sea ice. Rising temperatures cause the sea ice to melt earlier in the year, driving the bears to shore before they have built sufficient fat reserves to survive the period of scarce food in the late summer and early fall. Reduction in sea-ice cover also forces bears to swim longer distances, which further depletes their energy stores and occasionally leads to drowning. 

Thinner sea ice tends to deform more easily, which appears to make it more difficult for polar bears to access seals. Insufficient nourishment leads to lower reproductive rates in adult females and lower survival rates in cubs and juvenile bears, in addition to poorer body condition in bears of all ages.

In recent years, polar bears in the Arctic have undertaken longer than usual swims to find prey, resulting in four recorded drowning in the unusually large ice pack regression of 2005.

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