Global Environmental Change Assignment Example | Topics and Well Written Essays - 3000 words

Global Environmental Change - Assignment Example (Tollefson, 2009, p. 29) The arctic holds an important place in the debatable issue of maintaining life on earth in a sustainable way. However, this discussion centres on the Arctic region itself and more precisely on depleting population of the arctic Polar Bears rather than the chain effect of the susceptible artic on the rest of the world. The last hundred years have witnessed an increase in global temperature by 0.6 degree centigrade. (Jenssen, 2006, p. 78) Moreover from 1976 the rate is even higher and unmatchable by any time encompassing past thousand years. The effect of such rise in temperature is most visible through the extent of ice melting in the high and mid altitude area. In less than fifty years the snow has decreased by 10%. (Jenssen, 2006, p. 78) For the survival of a species, the survival of its habitat and food source is of utmost importance. With the rise in global temperature the extent of ice will decline in the Arctic and so will its duration of frozen state, resulting in less area for the seals to stay and breed. Seals are the most important food source of the polar bear; so any effect on their population will directly reduce the food basket of the polar bears. It has also been observed that for large mammals any change in global temperature affects the juvenile survival rate. From this point of v iew both the seal and the bear are equally exposed to risk. Therefore the bear suffers from two sides - reduced present and future food source and reduced juvenile survival rate. Again the polar bear hunts on ground (solid ice). Any reduction of ice extent will leave the bear with smaller ground to catch seals. (Jenssen, 2006, p. 78) In front of global climatic change the arctic ice plate has also undergone changes in terms of thickness and has become fractured in many places. Furthermore the ocean now freezes in later part of the year and all these in a cumulative way are depleting the habitat of polar bear. (O’Neill et al, 2008, p. 1650).