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Effects of Global Warming On Polar Bears and Polar Seals Introduction Polar bears depend on polar seals as a source of food in the polar region. Polar bears hunt polar seals before winter comes, so they can get all the proteins and fats they need in order to survive. Global warming is increasing the melt of ice in the Arctic region. As a result, polar seals will not be able to survive and face the environmental changes including climate. Therefore, polar bears will be threatened by starvation and then death. A 30 -year analysis of atmospheric carbon dioxide levels in Hawaii and Alaska, for instance, indicates that rising temperatures in winter and spring have stimulated forests and grasslands in the Northern Hemisphere: , causing spring growth to start a full week earlier than it did 20 years ago.
An unrelated study in the United Kingdom found that many species of birds are laying eggs roughly nine days earlier than in 1971. Of the 65 species studied, 20 - including wrens, magpies and wading birds - had made the shift, which scientists say could affect their long-term survival, since usual food sources arent as plentiful in an earlier time frame. In the Arctic, satellite measurements of sea ice show summer melting periods have increased at the rate of 5. 3 days per decade since 1979, lengthening the lean time for polar bears, which need solid ice to hunt ringed seals. A recent New York limes report also notes that Alaska is about five degrees warmer than it was 30 years ago, causing glaciers to retreat and permafrost to melt, ultimately affecting coastal wetlands like those in Mississippi and Louisiana, where scientists fear a corresponding rise in sea level would put submerged grass beds out of reach of redhead ducks and other species that depend on them. In an effort to curb activities that emit the pollutants suspected to be behind the warming trend, representatives from 160 nations agreed on the Kyoto Protocol last December.
Named for the Japanese city in which it was completed, it would require 39 industrial nations to stabilize emissions of gases like methane below 1990 levels by 2012. The other 121 nations - including most of the less developed countries, many of which argue that they should be allowed to strengthen their economy before imposing pollution controls - are so far exempt from regulation. (McNally) Discussion Global warming, of course, does have its own unexpected aspects. Until he came across an article by lan Stirling and Andrew Derocher in the September 1993 issue of Arctic, Ptolemy has to admit that he had not hitherto given much thought to the serious implications that the greenhouse effect has for polar bears. Arctic sea ice, it seems, is in a delicate climatic balance already. Global warming could lead to its complete disappearance, at least seasonally, and certainly can be expected to cause substantial reductions at the southern margin, in places such as the Hudson and James Bays. And ice is crucial to polar bear ecology: Polar bears depend on sea ice for several purposes: as a platform from which to hunt and feed upon seals... , as a habitat on which to seek mates and breed, as a vehicle from which to access terrestrial maternity denning areas, sometimes for maternity denning itself, and as a substrate on which to make long-distance movements (Pringle) It is tough enough being a bear even now.
According to Stirling and Derocher, the summer disappearance of ice from Hudson Bay requires the bears to fast for approximately four months. This leads to what are euphemistically described as negative human bear interactions which would presumably get even more negative if the summers increase in length. And it wont do the bear family much good if the maternity den is washed out by rain. Of course, there is always the possibility that bears will adapt, even if this means more negative human-bear interactions.
Another paper in the same issue of Arctic, by the same authors and Dennis Andriashek, reports clear evidence that mothers and young bears are already foraging for food mainly arctic blueberries and crowberries on land during the Hudson Bay summer. Presumably you have to pick a lot of berries as compared to a single seal, and the authors do not attempt to estimate the nutritional value of the exercise. But Ptolemy rather doubts that the bears are wasting their time. (Pringle) Scientists cannot see the future and therefore can only speculate on what the effects of global warming will be tomorrow. Yet, it is a known fact throughout the scientific community that global warming is going to get a lot worse if our attitudes arent changed about the environment. The greenhouse gases could warm the planet and have a huge effect on life, as it known on earth. Sea levels could rise due to melting glaciers and ice.
This could cause severe flooding and erosion in coastal regions. Harsh weather conditions have already become more fierce and frequent and could get much worse. Many plant and animal species may become extinct because they are unable to adjust at the rate the climate is changing. (Finley) The study also warns of dire consequences for the people and animals that call the Arctic home. This is very likely to have devastating consequences for some Arctic animal species... and for the local people for whom these animals are a primary food source. Should the Arctic Ocean become ice-free in summer, it is likely that polar bears and some seal species would be driven toward extinction, the ACIA report states.
Polar bears use the sea ice as platforms from which to hunt for seals, fish, and other food. Seals rest and give birth on the ice. A continued rise in temperature would affect other animals as well. Caribou, reindeer, and snowy owls, for example, would be forced to move farther north into a narrower range as their native habitat gets too warm.
Even the indigenous people of the Arctic are feeling the heat. Our homes are threatened by storms and melting permafrost; our livelihoods are threatened by changes to the plants and animals we harvest, said Chief Gary Harrison of the Arctic Athabaskan Council. Residents of Shishmaref, Alaska, are slowly losing their villages to storm-driven waves that were once restrained by the Chukchi Seas ice cover. Many people have moved their homes to escape the advancing waters. (Finley) Conclusion The ACIA report wasnt all bad news, however. There will be new opportunities too, Paul Prestrud, vice chair of the ACIA, told The Philadelphia Inquirer. The report noted that fisheries would be more productive with shorter winters.
Less ice would make it easier for ships to navigate the Northwest Passage and other treacherous sea routes. And oil companies would have easier access to oil and gas deposits beneath the Arctic tundra. Still, for many scientists, the good produced by global warming doesnt outweigh the bad. Susan Joy Hassol, the author of the ACIA report, told National Geographic that global warming must be slowed. A climate system is like a supertanker; you cant turn on a dime, so you have to turn the wheel now to avoid that iceberg [far] ahead. Bibliography: Struck, Ed.
Grizzlies on Ice. Canadian Geographic, Nov/Dec 2003, Vol. 123 Issue 6, p. 38. Finley, Will. On Thin Ice. (cover story) Current Events, 12 / 17 / 2004, Vol. 104 Issue 14, p. 1.
McCormack, Fiona. The Great Thaw. Scholastic News - Edition 4, 2 / 21 / 2003, Vol. 65 Issue 17, p. 4. Pringle, Rose M.
Such Low Temperatures in the Arctic Region How Can the Polar Bears Call It Home? Science Activities, Spring 2002, Vol. 39 Issue 1, p. 33. McNally, Robert Aquinas. White Bears, Black Oil. E Magazine: The Environmental Magazine, Nov/Dec 2001, Vol. 12 Issue 6, p. 10.
Free research essays on topics related to: effects of global warming, polar bears, sea ice, hudson bay, animal species
Research essay sample on Effects Of Global Warming Polar Bears
