Effects Of Global Warming On Polar Bears

Polar Bears & Global Warming
Linh Hua Polar bears are declining in numbers by years. “On May 14, 2008, the polar bear was listed under Endangered Species Act” (PBS).There are several reasons that are causing this specimen to disappear rapidly, such as hunting and predators, but the main reason for their degeneration is mostly due to the rise in temperature. “The melting of sea ice in both Arctic and Antarctic is changing migration patterns and food availability” (Enger and Smith, 252). Polar bears are marine mammals that live their lives primarily on ice, thus the melting of ice caps has had great effects on their environment, and the biodiversity in the Arctic. A polar bear is a type of large bear that lives in the Arctic. Different from

From all sources of media, most people are informed about global warming. Global warming is said to be the main cause of ice caps melting in the Arctic. Global warming is generally caused by greenhouse gas and deforestation. Greenhouse gases in the atmosphere is to keep the Earth warm, but with the excessive burning of fossil fuels like oil and coal over the years, the level of greenhouse gases have increased, making the temperature of the Earth rise as well. Deforestation also plays an important role on the escalating of temperature levels; the diminishing rate of trees on earth has a major effect on the atmosphere. Trees produce oxygen and take in carbon dioxide during their photosynthesis. The fewer trees the Earth has, the more carbon dioxide will stay in the

“In 2007, the Intergovernmental Panel on Climate Change estimated that Arctic summers would become ice free in the beginning of 2070” (Bogerson 162). On top of that, “in just three past decades, Arctic sea has lost half of its area and three quarters of its volume” (Bogerson 162). Less ice means less prey. Polar bears hunt for seals frequently, waiting for the seals to come out of the water and get close to the ice surface to breathe. The bear will try to grab the seal by biting its neck, then dragging it out of the water’s surface to eat. They also feed on seal pups that are in dens, dug in ice. Polar bears use their sense of smell to locate the prey in the Arctic ice. However, when there is more water than ice and the ice packs shrink, polar bears must travel long distance from one floating ice surface to another; and even worse, “the last remaining sea ice is over deep and unproductive waters that yield less prey” (National Wildlife Foundation). During their move, they can encounter storms and they can be drowned. Far distance travelling is also tough on cubs, for they do not have as much strength as an adult polar bear. Furthermore, “with more water seals do not need to rely as much on breathing holes and bears are less successful in obtaining food” (Enger and Smith 252). When it is harder to get food, the survival rate of polar bears will decrease and thus it makes them an