Polar Regions

 Climatic Changes and Projections

The Intergovernmental Panel on Climate Change has said that the polar regions are the most susceptible areas of the planet to current and projected climate change, and the regions are already experiencing sharp changes in weather patterns.

Over the past several decades, average temperatures in the Arctic have risen almost twice as quickly as other regions in the world, and extensive glacial melting, sea ice retraction and rise in permafrost temperatures further indicate a warming pattern. ^3a A 2004 Arctic Climate Impact Assessment report projected that Arctic temperatures will rise 5-7 degrees Celsius over the next century. ^4a Scientists have predominantly believed that much of the Antarctic continent has undergone a cooling trend in the past several decades, but the IPCC predicts this pattern to reverse, especially given the recent widespread retreat and collapse of ice shelves and increasing ocean acidity. {template.ref("3b")}} In fact, a breaking study published in Nature magazine in January 2009 provides convincing proof  that west Antarctica has warmed over a tenth of a degree Celsius per decade for the last 50 years, more than offsetting the cooling in east Antarctica.

It is likely that such changes in climate, which are projected to continue and increase in severity, will significantly impact the biodiversity of the polar regions. Many of the plant and animal species have evolved to particular climatic conditions such as constant snow cover or specific food availability, are poorly suited to defending against pests and parasites, and would compete poorly with alien species of a more adaptive nature. ^5a 

 Global Effects

The IPCC has noted that climatic changes in the polar regions could strongly impact global climate feedback systems through several processes: ^5b

• The high albedo, or reflectivity, of the brightly colored snow and ice causes solar radiation to reflect into space as the dark oceans absorb heat. As coverage of snow and ice declines the albedo of the polar regions will also decrease, causing more ice to melt and creating a feedback loop that leads to further warming.
• Increased river runoff, glacial melting and retraction of ice sheets will decrease the salinity of the oceans, which may have global implications on oceanic currents and sea level.

• Deposits of methane hydrates, sediment trapped in ice around the continental shelves, will likely escape as warming occurs. This is highly significant since methane is 21 times more potent as a greenhouse gas than carbon dioxide. ^2b Thawing permafrost may also emit carbon dioxide and methane into the atmosphere.  

Social Implications

Arctic communities are highly dependent on the local environment, and many inhabitants live traditional or subsidence lifestyles. Fishing and hunting support a particularly large part of both subsidence and commercial economies. The IPCC predicts that climate change may threaten food availability, resource management and culture for Arctic inhabitants. ^5c Inhabitants will also face safety risks as melting ice causes infrastructure support such as buildings, roads and pipelines to break down and traditional hunting grounds become unstable. ^4b 

Footnotes

¹: Central Intelligence Agency, The World Factbook. "Antarctica."  Retrieved on: December 31st, 2008.

^2a Andrew D. Kennedy, “Antarctic Terrestrial Ecosystem Response to Global Environmental Change.” Annual Review of Ecology and Systematics, Vol. 26, (1995), pp. 683-704.

^2b: Andrew D. Kennedy, “Antarctic Terrestrial Ecosystem Response to Global Environmental Change.” Annual Review of Ecology and Systematics, Vol. 26, (1995), pp. 683-704.

^3a The Environmental Protection Agency, "Polar Regions," EPA.org. Retrieved on: January 1st, 2009.

^3b: The Environmental Protection Agency, "Polar Regions," EPA.org. Retrieved on: January 1st, 2009.

^{4a 4b}: David J. Tenenbaum. "Global Warming: Arctic Climate: The Heat is On." Environmental Health Perspectives Vol. 113, No. 2 (Feb. 2005), p. A91.

^{5a 5b 5c}: Anisimov, O.A et al., 2007: Polar regions (Arctic and Antarctic). Climate Change 2007: Impacts, Adaptation and Vulnerability. Contribution of Working Group II to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change, Cambridge University Press, Cambridge. 

Resources

• Impacts of a Warming Arctic, the 140-page synthesis report of the Arctic Climate Impact Assessment

• Video - WWF, the global conservation organization: Observations on Climate Change in the Arctic