Recent studies showed that global warming very negatively affects North American polar bear population. In the past decade, their numbers decreased by about 50%. The research was conducted by US Geological survey together with the Canadian Ministry of Environment and climate change. Specialists were observing the bears living in Alaska as well as Yukon and other northwestern Canadian territories. Researchers came to the conclusion that between 2001 and 2010 the polar bear population decreased from 1,600 to 900.
Polar bears find their food on the icy surfaces where their white fur is not visible. This allows them to stalk seals that are swimming up to the surface through ice holes. If there is no ice, the bears will have much fewer chances to get food, which will lead to long-term hunger. The study showed that the worst polar bear population decrease happened between 2004 and 2007. During that time, only 2 out of 80 cubs survived. Usually, bear cubs have about 50% survival rate. Scientists believe that the reason for such disaster was hunger.
When a polar bear is hungry, it starts suffering from a condition called “walking hibernation”. Their metabolism process becomes similar to what brown bears are experiencing during winter time. However, as opposed to the brown bears, polar bears continue to stay awake, even though they move much less. The studies also showed that the bears are much more sensitive to hunger and climate change than was believed earlier, which means that global warming will have a terribly negative effect on them.
Why global warming threatens polar bears?
Global warming causes ice thinning in the cold regions. As a result, polar bears spend more time on the dry land during the warmer months of the year. The seal population has decreased and that led to bears trying to search for food near human settlements. Canadian and USA governments are arranging special patrols to minimize the contact between people and polar bears. However, these unpleasant encounters still happen.
Other recent studies of the deep snow and ice layers composition in the arctic region showed a very high level of the carbon dioxide. In the past 10,000 years, it never exceeded the concentration of 300 parts per million. However, since the industrial revolution, concentration of carbon dioxide in the air reached over 400 parts per million. If the tendency continues, the polar bears will die out in about 50 years. The animals will have just a small amount of ice to live on, while the snow will disappear completely. That will make their survival impossible.
Many studies have been done to identify the consequences of the global warming and most of them show that polar bears will become extinct in the next 20 – 50 years. People are trying to do everything possible to keep the polar bears alive. However, eventually, the humanity itself will make it impossible. Right now, scientists are looking for ways to decrease the global warming effects.