Global Warming And Polar Bears Essay Examples

1. Introduction
Global warming consequences have been mainly focused on the impacts they have and will in the future have on the global human population. The less focus is on the impact on the animal and plant species that are even more vulnerable, since they cannot adapt to quick changes as humans can. They are not the main culprit for the climate changes and yet they will suffer the most. One of the animal species that is being threatened by the global climate change are also polar bears that inhabit the polar region. They are playing an important role in the environment. Besides their importance of being a major tourist attraction and part of the arctic culture the decline of their numbers will affect the food chain and the whole marine environment. Polar bears are vulnerable because of the rapid climate changes which are causing their habitat to disappear, which is threatening their core existence and is posing threat of extinction. The paper will examine the threat caused to polar bears from global climate change. The thesis of the paper is that the continuation of the global climate changes consequences will result in the polar bear extinction.
2. Global climate changes in the arctic region
The total anthropogenic greenhouse gas emissions have been increasing since the year 1970 onward and have seen the largest increase in the recent years. The majority and hence around 78% of the emissions comes from the fossil fuels and industrial processes. The rising trend is connected with the increasing number of population and without the actions and efforts to reduce emissions the growth of temperature from 2.5 to 7.8 degrees Celsius will be seen by the year 2100 (International Governmental Panel on Climate Change, 6-10). The global climate changes are the most visible within the Arctic Circle. The Arctic and Antarctica have vast impacts on the global oceans and are major factors that contribute to the specific climate all around the globe. Based on the International Climate Change Panel (Anisimow & Fittharris, 807) the arctic regions are extremely vulnerable to the clime change and decreasing ice will have physical, ecological, economic and sociological impacts. This part of the world is reacting to the global climate changes more rapidly than any other part of the world. The impacts of rising temperature are shirking the ice, which will affect the water temperature, thawing of permafrost, altered landscapes in Northern America and Eurasia, loss of traditional way of life, increased biological production of some species and decrease of species that depend on the ice. Significant warming has been observed since the 20th century, which impacts the freezing of lakes and rivers. The glaciers and ice caps have been retreating since the year 1920 onward and snow cover has been reduced. The sea-ice in the Nordic decreased in the last 130 years for around 30% along with the drastically decline of snow extent are having vast consequences. The arctic glaciers and Greenland ice sheet will retreat and it is highly likely that Antarctic ice will also retreat in the coming centuries. With a doubling of carbon dioxide emissions the summer ice could shrink by 60% and result in the decrease of Arctic ice for 25%. The ice sheet will be declining as long as greenhouse gas concentration will increase (Anisimov & Fitzharris, 805-821).
With increasing temperature and with the solar and other techniques the thickness of ice has been measured from the 1970 onward. The Figure 2 is shows the 25 year decrease of the sea ice in the Northern Hemisphere, which will greatly impact the habitats of the polar bears. The thickness of ice has been decreasing from the year 1970 onward. Polar bears and their prey are dependent on the sea-ice for resting, reproduction and foraging. The whole arctic ecosystem is impacted by the global climate changes. The threats to polar bears, ice seals and other species are in the greatest threat since the recorded history. There have been various different climate models that include different factors of measurement. The most drastic scenario and modeling have predicted that in the next 50 years the whole Arctic basin will be without ice cover (National Oceanic and Atmospheric Administration, n. p.).
Figure 1 Decrease of ice in the last 25 years
Source: National Oceanic and Atmospheric Administration, n. p.
3. Shrinking of the polar bear habitat
The trend of the polar bear population can be best presented with the studies and trends on polar bears in Canada Hudson Bay. With the harvest and hunting along with the impacts of the global climate change and decreasing of ice sheets, polar bears will without the mitigation disappear from some subpopulation. Polar bears are dependent upon the sea for accessing their food and for prey. The melting of ice therefore represents one of the most important threats to their sustainability. The threat comes also from hunting and from the pollution. Without the resolving of issues regarding the concentration of the greenhouse gas emissions the global temperature will rise and the ice will melt and endangered polar bears. Currently 19 populations of polar bears are distributed in circumpolar Artic. They can be found in areas where sufficient energy reserves for their survival exist. Ecoregions of their habitat are defined. Based on the Figure 1 there are various regions and polar bears are confronted with seasonal sea ice areas where the ice melts entirely in the summer and bears are forced ashore for long periods of time with which they have less access to food. In the areas of divergent and convergent sea ice polar bears must seek food on the shore longer periods in the year. Only in the Arctic Archipelago their habitat is unchanged on the surface and where they have the ice through the whole year. The greatest risk from climate change is facing the divergent and convergent ecoregions and the least risk to polar bears is seen in the Archipelago ecoregion (Aars et al., 3-10).
Figure 2 Ecoregions of polar bears
Source: Aars et al., 8.
The estimated most examined subpopulation of polar bears in Western Hudson Bay has seen the long term declining size. The population size of the polar bears is very important indicator for harvesting as making trend prediction of the population itself. The exact numbers are hard to determine. Polar bears are scattered around different geographical areas and they are solitary and camouflaged with snow. The determination of the population is usually done with the observations and monitoring (Aars et al., 11-19).
There have been suggestions of the polar bear adoption to the warmer climate. Some have been arguing that they can eat a variety of food such as berries, mammals, sea ducks, bird eggs and seaweed. Based on the polar bear composition and tissue the changed eating habit does not show the adoption, but rather loss of the primary habitat. There were suggestions that they could maintain their body fat during the ice free periods, but they did not take into an account that they weigh more than 280 kg and that solely relying on the food available on the shore would not suffice and is not sufficient to provide enough energy that polar bears use on the annual basis. Further on even they are eating vegetation their digestion track is not adapted. Polar bears are predators and their survival depends on the access to seal population and ice cover that helps them to hunt (Derocher & Stirling, 2694-2706).
4. Global climate change impacts on the polar bear population
Polar bears have increased the use of onshore food because of the sea ice loss, which impacted their feeding patterns. Feeding on the low calorie food on vegetation and eggs is a result of the lost opportunities to hunt seal and they have lost possibilities of the quality food consumption. Survival rates are impacted by the sea ice conditions. The loss of habitat is evident in the different patterns of their distribution. They spend more time on the land because of the loss of ice and they have limited terrestrial food which is not abundant (Amstrup, Nelson, Robbinson, Rhode, 138-145).
The global climate change and the effect of warming have reduced the capacity of existing habitat of polar bears since the capacity of the habitat to support population is declining. The carrying capacity will in the future continue to pose a threat. The warming impacts the reproductive rates. With the decreasing areas of habitat the food provision for the polar bears will be hindered (Aars et al., 18).
There are various factors that show the possibility of the polar bears extinction. The rise of the temperature and the melting of the polar ice are the major concerns. Those are the two main consequences of the climate change that are threatening the wellbeing and survival of the species. With the warmer weather in winter the dense are reduced that are built to give birth and to protect the newborn polar bears, which results in the loss of habitat in the warmer part of the year. The most concerning issue is that the climate changes in this part of the world are much faster with an ice declining rate of around four percent per ten years. The finding of food and essential to survive are getting harder. With shrinking ice cover, which is decreasing faster at the beginning of the year and forming later as in the past the feeding time is reduced in the spring and in the autumn (Pidcock, n. p.).
Based on the National Oceanic and Atmospheric Administration (n. p.) that minor changes could have drastic impact on the polar bears. Based on the Polar Bear Specialist Group there are three major negative impacts of the global climate change on the polar bears. Climate change will leave an impact on the polar bears prey, alter the period of ice cover will result in different distribution and climate change will negative impact the denning. The first negative impact will therefore represent in prey reduction that will impact the survival and cub production of polar bears. The second biggest impact will be shown in the increased time spend on the land and increased use of terrestrial areas, which would affect the physical condition which would further impact the survival and reproduction. Polar bears will have less food and spend more energy since instead of swimming they will need to walk to find food. The last mentioned negative impact can result in limited high quality denning areas and usage of more inappropriate habitat could result in a decrease in reproduction and survival rates. The warmer weather patterns could result in collapse of snow dens (National Oceanic and Atmospheric Administration, n. p.).
It has been estimated that from 28 to 48% of the adult polar bear males would die if the ice-free period increased to 180 days. They would die of the exhaustion and lack of energy. The impacts on the females would be bigger than on males, which would mean decreased reproduction. The modeling was done in the Hudson Bay on which the most data exist. The decline of the body size has already been noticed (Derocher & Stirling, 2694-2706).
The polar bears are on the top of the food supply chain in the arctic. The global population has been estimated at 20.000-25.000 individuals. Their habitats differ based on the area of residing and it is dependable on the prey availability. They have been categorized as a vulnerable group, because of the loss of habitat, which is threatening the biological diversity. The ice is essential for the sustainability and preservation. If the current forecasts are going to come true, by the 2050 the majority – two thirds of the polar bear will be extinct (World Wildlife Fund, 1-4).
5. Conclusion
Polar bears are confronted with threats coming from industry, pollution, hunting and the most perilous global climate change. The consequences are the most drastic in the areas of their habitat. The rising temperature because of the increased greenhouse gas emissions will increase the loss of the ice sea and snow cover which will put polar bears in a position that can be exposed to the extinction in the near future. We can confirm the thesis of the paper because with the continuation of the global climate change consequences will result in the polar bear extinction in unchanged living and acting patterns of global human population.
6. Bibliography
Amstrup, C. Steven, Nelson, Lynne, Robbinson, T. Charles, Rode, D. Karyn. Can Polar Bears Use Terrestrial Foods to Offset Lost Ice-Based Hunting Opportunities. Frontiers in Ecology and the Environment. Vol 13 (2015): 138-145.
Anisimov, Oleg, Fitzharris, Blair. 2014. Polar Regions: Arctic and Antarctic. International Panel on Climate Change. <https://www.ipcc.ch/ipccreports/tar/wg2/pdf/wg2TARchap16.pdf>
Aars, Jon, Amstrup, Steve, Atkins, N. Stephen, Belikov, Stanislav, Born, W. Erik, DeBruyn, D. Terry, Derocher, E. Andrew, Durner, George, Gill, Mike, Lunn, Nivk, Obbard, E. Martyn, Omelak, Jack, Ovsyanikov, Nikita, Peacock, Elizabeth, Richardson, Evan, Sahanaties, Vicki, Strling, Ian, Vongraven, Dag, Wiig, Oytein. A Circumpolar Monitoring Framework for Polar Bears. International Association for Bear Research and Management. 2012. http://pbsg.npolar.no/export/sites/pbsg/en/docs/Vongraven2012UM.pdf
Derocher, E. Andrew, Stirling, Ian. Effect of Climate Warming on Polar Bears: a Review of the Evidence. Global Change Biology, Vol 18 (2012): 2694-2706. < http://onlinelibrary.wiley.com/doi/10.1111/j.1365-2486.2012.02753.x/full>
International Panel on Climate Change. Climate Change 2014: Mitigation of Climate Change. 2014. <http://www.ipcc.ch/pdf/assessment-report/ar5/wg3/ipcc_wg3_ar5_full.pdf>
Pidcock, Roz. Polar bears and climate change: What does the science say? 04 March 2015. <http://www.carbonbrief.org/polar-bears-and-climate-change-what-does-the-science- say>.
National Oceanic and Atmospheric Administration. What has Been Happening to the Polar Bears in Recent Decades? N. d. < http://www.arctic.noaa.gov/essay_schliebe.html>
World Wildlife Fund. Effects of Climate Change on Polar Bears. 2015. <http://assets.worldwildlife.org/publications/398/files/original/Effects_of_Climate_Ch ange_on_Polar_Bears_fact_sheet.pdf?1345754206&_ga=1.221543568.965393764.14 57721902>