Polar Bear Ecology: as Impacted by Global Warming

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Erin Napp
12/2/2012
Ecology
Polar Bear Ecology:
As Impacted by Global Warming
Our country is home to a diverse array of wildlife ranging from the highest peaks, to the driest deserts, to freshwater and marine environments and to all the places in between. The abundant and diverse wildlife resources, which are so important to our culture and well-being, face a bleak future if we do not address global warming ("Effects on wildlife"). Polar bears are in danger of extinction as well as many other species. Polar bears are found in the Arctic Circle and surrounding land masses. There are 19 recognized subpopulations, and estimates place their numbers at about 20,000 to 25,000. Polar bears are classed as vulnerable by the World Conservation Union (IUCN) and listed as a threatened species under the US Endangered Species Act. Yet some claim that polar bear numbers have increased since the 1950s and are now stable. So what is the situation for this species? First of all, a few points need to be made about polar bear numbers: Nobody really knows how many bears there were in the 1950s and 1960s. Estimates then were based on anecdotal evidence provided by hunters or explorers and not by scientific surveys. Polar bears are affected by several factors, including hunting, pollution and oil extraction. Most notably, hunting, particularly following the introduction of snowmobiles, airplanes and ice breakers, led to a huge decline in certain subpopulations. The introduction of the International Agreement on the Conservation of Polar Bears in 1973, which restricted or even banned hunting in some circumstances, consequently resulted in an increase in polar bear numbers. Not all subpopulations are affected to the same degree by climate change, and while some subpopulations are well studied, for others there is insufficient data to make broad statements about current and past numbers. With this caveat in mind, what do the figures actually say? According to a 2009 report by the...
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