Download The Detrimental Effects of Climate Change on Polar Bear Populations

EFFECTS OF CLIMATE CHANGE ON POLAR BEAR POPULATIONS
The Detrimental Effects of Climate Change on Polar Bear Populations
Alex Cowan
Sheridan Institute
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THE DETRIMENTAL EFFECTS OF CLIMATE CHANGE ON POLAR BEAR POPULATIONS
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Table of Contents
Abstract............................................................................ Error! Bookmark not defined.
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Background........................................................................................................................ 4
Effects of Climate Change on the Arctic and the Polar Bear Population .......................... 4
Human Influence on Climate Change ............................................................................... 5
Human Responsibility to Protect Arctic Wildlife ............................................................. 7
Conclusion ......................................................................................................................... 8
References ......................................................................................................................... 9
THE DETRIMENTAL EFFECTS OF CLIMATE CHANGE ON POLAR BEAR POPULATIONS
Abstract
The purpose of this report is to focus on human responsibility for climate change
and the results on the polar bear population. This report explains the effects of climate
change on polar bear populations. It affirms that the warming climate will lead to the
erosion of the polar bears’ habitat and ultimately to their extinction. The report
identifies environmental issues caused by man and their consequences. Furthermore,
this report emphasizes the importance of human action in preserving Arctic wildlife.
Research for this report was collected from online journal articles and government
websites.
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THE DETRIMENTAL EFFECTS OF CLIMATE CHANGE ON POLAR BEAR POPULATIONS
The Detrimental Effects of Climate Change on Polar Bear Populations
The Canadian government defines climate change as a long-term shift in weather
conditions identified by changes in temperature, precipitation, winds, and other
indicators (2012, para. 1). The government states that the causes of climate change are
both natural and human (2012, para. 2−3). Climate change is causing Arctic
temperatures to rise and remain elevated for longer periods, resulting in melting sea ice
and the erosion of polar bears’ natural habitats.
Background
Currently Arctic temperatures are on the rise and remain elevated for longer
periods of time, evident in the sea ice formation and breakup. The sea ice is now
forming later in the winter season and is melting sooner in the spring. The Arctic
Ocean's ice cover reached a record low this summer and long-term trends predict that
the Arctic will soon be ice-free for the first time in millions of years (Emerson, E.,
2012). This disruption in the environment directly affects the polar bears habitat,
feeding and mating patterns.
Effects of Climate Change on the Arctic and the Polar Bear Population
As the atmosphere in the Arctic warms, the snow and ice melt cause a rise in sea
levels and a reduction of land mass. According to Andrew Derocher “the projected loss
of polar bear sea-ice habitat as a result of a warming climate will dramatically reduce
the spatial and temporal extent of that habitat by the end of the twenty-first century”
(2010, para. 1). With global warming causing the sea ice to freeze later in the winter
and melt sooner in the spring, the polar bears have a minimized habitat. The bears now
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THE DETRIMENTAL EFFECTS OF CLIMATE CHANGE ON POLAR BEAR POPULATIONS
have less space to roam, causing the population to be more condensed.
The early sea-ice breakup is limiting access to major seal populations, which are
the bears’ main food source. The bears require high fat diets and can feed on walrus and
beluga as well, but since they are also ice-associated prey, they too are hard to access
(Peacock, Derocher, Thiemann, & Stirling, 2011). With decreased nutrition comes a
string of other problems including starvation or resorting to cannibalism, particularly
males feeding on young cubs. If polar bear cubs are hunted as food, the future bear
populations will ultimately be depleted.
The bears' mating season is disrupted by the changing climate. Derocher mentions
that there has been a slow decline in polar bear populations along the Hudson Bay "due
to the lower survival and reproduction that is correlated with reduced sea-ice duration"
(2010, para. 3). As well, he states polar bears have low reproduction rates and even if
there is recovery after loss of sea ice, the change will still have serious effects on the
bear population (2010, para. 3−4).
Human Influence on Climate Change
Human activity plays a large role in climate change through the way we live our
everyday lives. For years, the human population has been driven to find the most
efficient way to fulfill our wants and needs. However, discovering the quickest way to
meet our needs has lead us to overlook the environmental hazards that result from our
actions. Over time humans have sacrificed health and clean environment for
productivity and efficiency.
The Canadian government states "the overall effect of human activities since the
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THE DETRIMENTAL EFFECTS OF CLIMATE CHANGE ON POLAR BEAR POPULATIONS
Industrial Revolution has been a warming effect, driven primarily by emissions of
carbon dioxide and enhanced by emissions of other greenhouse gases" (2012, para. 4).
The Canadian government also believes that if we continue to produce consistent
amounts of greenhouse gas, the planet may heat up to levels that have never been
experienced before (2012, para. 4−6). If this warming trend continues, the Arctic
climate will change and the current ecosystem will be drastically altered. This leaves
the prospects for polar bears fairly grim since they are biologically built to live in a cold
climate.
Another human influence on climate change has been the production of harmful
chemicals such as POPs, persistent organic pollutants, which are found in pesticides
and in industrial waste. Most of these pollutants are released into the atmosphere in the
more central regions of the world and they are turning up in the Arctic by way of
northward atmospheric transport. However the ocean and wind currents naturally
stream northward, carrying all the pollutants to the Arctic.
These POPs are turning up in the fat tissue of polar bears because of
bioaccumulation. Studies are showing that these POPs are causing a reduction in the
polar bears’ bone mineral density and are causing birth defects, such as malformed sex
organs (Air/Water Pollution Report, 2001; Tenenbaum, 2004). POPs have been banned
in most countries, so they are no longer being released into the atmosphere. This
change will not reverse the damage that’s already been done, but it will help preserve
the future generations of polar bears.
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THE DETRIMENTAL EFFECTS OF CLIMATE CHANGE ON POLAR BEAR POPULATIONS
Human Responsibility to Protect Arctic Wildlife
"To work in the fields of polar bear ecology, conservation, and management in a
rapidly changing world requires optimism about humans’ ability to reduce the levels of
greenhouse gases that threaten the persistence of polar bears and their ecosystems"
(Peacock et al., 2011).
The effects of climate change on the Arctic are causing great stress on the polar
bear population. It is our responsibility to protect this threatened ecosystem. We must
do everything we can to reverse the damage we have caused. People need to do their
part in finding ways to reduce the amount of pollution being released into the
atmosphere. By being more conscious of how we are influencing our surrounding
ecosystem, we can slow the effects of climate change.
The Canadian government has implemented the federal Species at Risk Act: "The
purposes of this Act are to prevent wildlife species from being extirpated or becoming
extinct, to provide for the recovery of wildlife species that are extirpated, endangered or
threatened as a result of human activity and to manage species of special concern to
prevent them from becoming endangered or threatened" (Species at Risk Act, 2002).
This Act is a good start to the preservation of polar bears, but we all must do more.
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THE DETRIMENTAL EFFECTS OF CLIMATE CHANGE ON POLAR BEAR POPULATIONS
Conclusion
The evidence is clear that climate change is causing Arctic temperatures to rise,
and as a result the polar bear population is being negatively affected. Through study
and analysis of the polar bear population, it is obvious that they are already
experiencing difficulty surviving in the warming climate. With the sea ice forming later
in the winter and melting earlier in the spring, the bears are losing their habitat and
access to their main food source. It is evident that humans have played a role in the
cause of global warming through our excess production of greenhouse gases and
release of harmful chemicals into the atmosphere. As humans are part of the cause of
the deterioration of the Arctic ecosystem, it is our duty to help slow the effects of
climate change through the reduction of greenhouse gas emission going forward.
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THE DETRIMENTAL EFFECTS OF CLIMATE CHANGE ON POLAR BEAR POPULATIONS
References
Derocher, A. E. (2010). The prospects for polar bears: Is the polar bear doomed to
extinction? Nature, 468.7326. Retrieved from
http://go.galegroup.com.library.sheridanc.on.ca/ps/retrieve.do?sgHitCountType=No
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Emerson, E. (2012). Shrinking ice in the Arctic offers an uh-oh moment. Science News.
182.7. Retrieved from
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Government of Canada. (2012). Causes of climate change. Retrieved from
http://www.climatechange.gc.ca/default.asp?lang=En&n=65CD73F4-1
Government of Canada. (2002). Species at Risk Act. Retrieved from http://lawslois.justice.gc.ca/eng/acts/S-15.3/page-2.html#h-4
O’Neill, S. J., Osborn, T. J., Hulme, M., Lorenzoni, I., & Watkinson, A. R. (2008).
Using expert knowledge to assess uncertainties in future polar bear populations
under climate change. Journal of Applied Ecology, 45, pp. 1649−1659. doi:
10.1111/j.1365-2664.2008.01552.x
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THE DETRIMENTAL EFFECTS OF CLIMATE CHANGE ON POLAR BEAR POPULATIONS
Peacock, E., Derocher, A. E., Thiemann, G. W., & Stirling I. (2011). Conservation and
management of Canada’s polar bears (Ursus maritimus) in a changing Arctic. Can.
J. Zool, 89, 371-385. doi: 10.1139/Z11-021
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Researchers consider link between POPs and polar bear abnormalities. (2001).
Air/Water Pollution Report. 39.21. Retrieved from
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Tenenbaum, D. J. (2004). POPs in polar bears: Organochlorines affect bone density.
Environmental Health Perspectives. 112.17. Retrieved from
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