Polar Bears Warming Up to Climate Change

The way the earth’s climate has been changing is a very hot topic among scientists today.  Some believe it to be caused by the earth’s natural geothermal development and part of the normal change that the planet should be undergoing. Others contradict these claims by saying that man’s own inventions and improper use of fossil fuels has been aggravating the natural thermal changes.  Environmentalists further urge the general public to act towards helping preserve earth because man’s activities are not only lessening human survival but of his co-planetary habitants as well.

Polar Bears’ Hierarchy in the Arctic Kingdom

            Polar bears are known to be the world’s largest land predator. (Briggs, 2003, par. 9) Adult females normally weigh 330 to 550 pounds but males can be as heavy as 775 to 1500 pounds. (Polar Bears International, 2008, par. 4)

            Polar bears, as can be shown in the Food Chain Model below, are on top of the food chain in the arctic regions and feed on ringed seals and walruses.

Get quality help now

Dr. Karlyna PhD

Verified writer

Proficient in: Climate Change

4.7 (235)

“ Amazing writer! I am really satisfied with her work. An excellent price as well. ”

+84 relevant experts are online

Hire writer

Polar Bear

Beluga                  Ringed Seal          Thick-Billed Murres               Walrus

Bowheaded Whale                Arctic Cod                 Arctic Tern

Zooplankton

Phytoplankton

            Although humans have taken it upon themselves to care for their environment, sharing responsibility is not always easy. There used to be concerns between Norway and Russia, as to who should be responsible for the care of the Ursus maritimus or polar bear since they can be found in both countries.  A study made by Mette Mauritzen (2002) and her colleagues used satellite telemetry to obtain data from 105 female polar bears over a dozen of years and the results showed that the different subpopulations in the different locations are all part of one continuous polar bear population.

  This means that both countries need to share management responsibility for the species.

Global Warming and the Arctic

            Many scientists are saying that the current state of global warming is too fast.  Some say that it will only take around 50 years before the ice in the Arctic will melt while others say it may take around 100 years.  The length of time is irrelevant because the urgency of combating global warming can truly be seen with its predicted and already on-going effects. According to NASA Engineer Josefino C. Comiso (2003), his satellite observations show that the twenty year trend in situ surface temperature is eight times larger than the 100 year trend which means that the sea is warming much faster than normal. He also presumes that by the year 2050, the ice lying over the continental shelf would be displaced into the polar basin.

Polar Bears and Global Warming

            According to an article written by Eric Chivian (2001) entitled Environment and health:  Species loss and ecosystem disruption — the implications for human health,  global climate change, stratospheric ozone depletion, and the negative results of other man-made activities threaten biodiversity, but it is the degradation, reduction and fragmentation of habitats that is the greatest threat.

            According to a very extensive study made by Andrew Derocher, Nicholas Lunn and Ian Stirling (2004) entitled Polar Bears in a Warming Climate, factors such as the decreasing area of Arctic Sea Ice, lessened multiyear ice, timing of ice formation or break-up, denning, movements of the bears on the sea ice, quantity of prey, human-polar bear interactions and pollution all combine to threaten the survival of the species.

Arctic Sea Ice                                                                                                     

            According to the IUCN/ Species Survival Commission Polar Bear Specialist Group (2002, pp. 21-35), polar bears have been able to occupy sea ice habitats throughout the Arctic with its population estimated at 21,500 to 25,000. Arctic Sea Ice are used by polar bears to transport themselves over the water to prey on seals.  Lessening the number of arctic ice would greatly affect the food resource of the species.

Lessened Multiyear Ice                                

            According to a previous report by Comiso (2002b cited in Derocher, 2004) the ice cover in the Arctic is already declining at the rate of 9% every ten years; which means that the ice may be all gone in just one hundred years. Since polar bears are fully dependent on their icy habitat, losing the ice can lead to their extinction.

Timing of Ice Formation and its Break Up

            One of the basic things that will be affected by global warming would be the cycle of break-up and freezing of the annual ice in the arctic.  Some scientists believe that global warming affects the cycle by making the ice break up earlier annually while delaying its freeze.

In Canada’s Western Hudson Bay, the annual ice break-up is observed to be occurring about 2.5 weeks earlier than 3 decades ago. (Stirling, et.al. cited in Derocher, 2004) This is important because when the ice breaks sooner, the polar bears have shortened time to feed on seals which can greatly affect the conditions of their bodies throughout the year.  Their bodies would not have been able to get enough of the fat they would need for their four-month fast.

            According to other studies previously done by Derocher and Stirling (1995b cited in Derocher, 2004), adult polar bears lose around .85 to .90 kilograms of body mass daily during fasts.  With the abrupt breaking of ice that would end feeding period earlier and the delayed freezing, polar bears will lose their weight abnormally due to the longer time they need to fast.

Although it may seem trivial, this has a significant effect on the pregnant polar bears.  If these female pregnant polar bears fall beyond 189 kilograms of weight due to the long fasting period, chances of delivering the cub become nil.

Denning

            Female polar bears have favorite places to den. To reach these places, the ice cycles should be regular to be able to help these bears reach their destinations on time. Also, with the ice melting and making the area farther to swim to, it is becoming difficult for polar bears to reach their favorite locations.

            There are some subspecies that do may not be particular with their den locations because they are able to den on drifting multiyear ice.  These polar bears are currently able to raise the cubs well.  However, with global warming affecting the multiyear ice, these bears may have to be on the floating ice longer than necessary which means more energy wasted.  This can also be detrimental to the cubs which are not yet fully developed and equipped to weather the weary conditions. If this happens, then global warming will affect the population because of the cubs that can be lost due to the conditions mentioned.

            For polar bear populations that prefer to go back to their maternity dens, another problem that could threaten their natural activity would be that while the planet warms, the flora and fauna in the area would also be drier making these prone to fire.  Warmer dens with fire-risks are not suitable for pregnant polar bears and their cubs.

Movements of Polar Bears on the Sea Ice

            Because of warmer sea temperatures and an increase in sea winds due to global warming, sea ice will thin easily and this may cause this major transportation for polar bears to become unstable or drift faster. If it moves much faster, the species would need to spend more energy in reaching their preferred locations. Although polar bears love to swim, using too much energy can also cause poor health and reproduction for the polar bears. Observations also note that polar bears move to land when sea ice quantity goes below half of its normal number. This could be because more energy is spent moving on top of drifting ice compared to walking on solid icy ground. A decrease in the number of sea ice drifting also lessens the opportunities to hunt for more prey.

Availability of Prey

            A decrease in sea ice has its effects on the productivity of seals, which are the main food of polar bears.  Seals rely on sea ice for their maternity activities, lessening the quantity of sea ice drifting due to global warming will also lessen the population of seals.

            There were observations in 1979 that warmer temperatures and rain resulted to the easy uncovering of seal pup lairs that made it thrice easier for polar bears to catch them. (Hammil and Smith, 1991 cited in Derocher, 2004) If this can become a trend wherein in warmer temperatures will cause the earlier onset of rain which will wash away the protection of seal pups, then, it is also possible that the population of ringed seals will decline as newborns are given less chances of survival.

            Polar bears rely on sea ice to be able to catch seals.  Lessening the number of sea ice would also decrease its opportunities to catch the prey.  Very few polar bears have been observed to have enough ability to catch its prey in open waters. The species may have more luck in getting their food when walrus or seals are hauled out on terrestrial habitats but only few individuals of the species are known to have this ability.

            Another aspect that needs to be discussed is the way the polar bears eat their prey.  The adult male polar bears prefer the blubber of their prey and usually leave much of the protein behind (Stirling and McEwan, 1975 cited in Derocher, 2004) for younger polar bears who are not yet good in catching prey.  With global warming altering the food sources and the way polar bears spend their energy, there will likely be less left-over food for the younger generations of cubs to eat which can decrease the population size.

Human Bear Interactions

            So far, human and polar bear interactions have been relatively few because of the difference of habitat these species share.  However, if global warming will cause the ice to melt and lessen the current quantity of food, the bears may have to wander nearer human dwellings for their own chances of survival. However, this can be fatal for both species because humans may have to get rid of the polar bear for protection or else the bear will consider the human its prey.  More human interaction will also increase the polar bears’ exposure to pollutants which can affect its population.

Remediation Program

            Polar bears have been under the protection of the different governments their habitats are found.  There are already laws in place to ban hunting except for scientific purposes and changes in marine transportation routes to lessen the pollution that can endanger the species.

            However, global warming is still an issue that can be better addressed by the public.  Although more and more advocates have been trying their best to cause enough awareness about the problem of greenhouse gases, a good remediation program for the polar bears would be dependent on a good program against global warming.

            The greenhouse effect of global warming is said to be caused by methane and carbon dioxide which form a layer in the atmosphere.  This layer keeps the heat being produced within the earth from going out of the planet under normal atmospheric circumstances. Carbon dioxide is a natural gas humans and animals excrete when they process oxygen while methane is released into the atmosphere when the earth is being dug up.  Polluted air from vehicles are also carbon dioxide emissions that hasten the greenhouse effect.  There are other sources of global warming such as the destruction of the ozone layer due to man’s use of chlorofluorocarbons (CFCs), over population while decreasing tropical rain forests, etc.

            To help stunt the detrimental effects of global warming, people and governments must put aside financial gains and demerits because not only do the polar bears need to survive but man as well. There are already many programs being done by different environmentalists like the International Union for Conservation of Nature (IUCN), Humane Society of the United States and International fund for Animal Welfare to help lessen the threats on polar bear survival.

            Global warming has already been addressed world-wide and one of the agreements that had never been fully implemented is the Kyoto Protocol.  Many countries including the United States and United Kingdom have signed and agreed to the terms of the bargain wherein the member governments will bring down their carbon dioxide emissions to levels safer for humans and other creatures alike.  According to the treaty, these nations would also exchange technologies that could help reverse the problems of global warming.

            However, the U.S. and other countries failed to implement it and continue to bypass the promises made during the planning of this pact.  Therefore, I believe that remediation programs are already in place but these need the sincerity of governments, especially the ones powerful economically, to succeed.

            Beyond government efforts, individuals can truly help force governments to fulfill their environmental obligations by lobbying for the implementation of the Kyoto Protocol and other environmental issues.

            In 2006,  Julius Kenneth Ningu and his colleagues made a report on how the North American Free Trade Agreement (NAFTA) was creating negative effects on Mexico’s environment. According to the report, the country had good environmental policies in place and the government was strict in implementing it until the agreement forced it into an economic crisis.  In just a few years, the government had to relax on its environmental policies to enable private corporations to weather the economic crisis and for the country to be able to meet the standards of the agreement.  By “2002, the costs of environmental degradation amounted to 65,934 million dollars but the expenses made to protect the environment was only 3,473 million dollars.” Governments must therefore also be forced to put into place stricter laws that would protect the environment (not only of their own country but of the countries they deal with for capital growth).

            Lessening use of fossil fuel is a must and the public must support the new inventions being made that would help decrease the problem of global warming. Spending more money on machines that produce cleaner air may be more expensive but worthwhile in terms of survival.

Scientific Debates

            Polar bears are very cool in their own habitat and naïve to how scientists continually debate on whether they are going towards extinction or not. Some believe that climate change will not pose substantial problems with polar bear species survival while a relevant population in the scientific community believes that the melting of the ice in these mammals’ habitat will threaten their existence. The U.S. Senate has already debunked the idea that polar bears are going towards extinction because of reports that the polar bear population is at its highest peak as of the current years and that research already shows that the species can was able to withstand the interglacial  period which was much warmer . (US Senate, 2008)

Conclusion

            The survival of polar bears may not be a big issue as of the moment because it can actually be true that they can survive even worse temperatures.  However, global warming is not just an issue worth noting for polar bear survival but for human existence as well.  Governments must find the will to implement the laws that they already know are correct to be able to help all humans survive.  It is only through the sincere will of strong and economically stable governments that a cool change can really be met.

References

Assignment Discovery School  Lesson Plan. (n.d.). Retrieved April 2, 2008, from

            http://school.discoveryeducation.com/lessonplans/pdf/biomes_wildarctic/biomes_wildarc

            tic.pdf.

Briggs, H. (2003). Polar Bear ‘Extinct Within 100 Years.’ BBC News, Science/Nature. Retrieved

            April 2, 2008 from http://news.bbc.co.uk/2/hi/science/nature/2642773.stm.

Chivian, E. (2001). Environment and health: 7. Species loss and ecosystem disruption — the

            implications for human health. Canadian Medical Association Journal, Vol. 164 (3). 365-

            369.

Comiso, J. (2003). Warming Trends in the Arctic from Clear Sky Satellite Observations. Journal

 of Climate, Vol. (21), pp. 3498-3510.

Derocher, A., Lunn, N.J. and Stirling, I. (2004). Polar Bears in a Warming Climate. Integrative

            and Comparative Biology 2004 44(2),163-176.

IUCN/SSC Polar Bear Specialist Group. (2002) In N. J. Lunn, S. Schliebe, and E. W. Born

            (eds.), Polar bears: Proceedings of the 13th Working Meeting of the IUCN Polar Bear

            Specialist Group. IUCN, Gland, Switzerland and Cambridge, U.K.

Mauritzen, M., Derocher, A.E., Wiig, O., Belikov, S.E., Boltunov, A.N., Hansen, E., et.al.

            (2002). Using satellite telemetry to define spatial population structure in polar bears in

            the Norwegian and western Russian Arctic. Journal of Applied Ecology 39 (1) , 79–90.

Ningu, J.K., Jacome, J.T., Silva Gomez, S.E. and Aviles, R.P. (2006). The Effects of North

            America Free Trade Agreement on Mexican Environmental Policy (1994-2004).

            American Journal of Environmental Sciences Vol. 2(1). Pp. 5-8.

Polar Bears International. (2008). About the Polar Bear. Retrieved April 2, 2008, from

            http://www.polarbearsinternational.org/bear-facts/about-the-polar-bear/

U.S. Senate Environment and Public Works Committee. (2008). U.S. Senate Report Debunks

Polar Bear Extinction Fears. Retrieved April 2, 2008, from http://epw.senate.gov/public/

index.cfm?FuseAction=Minority.Facts&ContentRecord_id=cb2faa9c-802a-23ad-4bcc-

29bb94ceb993.