Reduced Sea Ice

As a result of warming temperatures, sea ice cover on the Arctic Ocean has declined by 5.5 percent between 1980 and 1994 - a loss of almost one million square kilometres. [14] The Arctic food chain is largely founded upon microorganisms which grow on the underside of sea ice. Thus a reduction in sea ice could cause a food chain collapse and sharply reduce the productivity of the Arctic Ocean.

Many arctic animals, such as seals and the polar bears that feed on them, depend on sea ice for their survival. In some parts of the Subarctic, polar bears must fast during the summer because of the absence of sea ice upon which to hunt seals. A longer summer season of reduced ice cover would place se-vere stress on populations.[15] Some mod-eling suggests that a doubled level of green-house gases would melt almost all Arctic sea ice in summer. [16]