Arctic Sea Ice: A Vanishing Kingdom

The Intergovernmental Panel on Climate Change has confirmed that human-induced climate change is a reality. It can no longer be dismissed as a theoretical, academic, concept nor a politically motivated doomsday prophecy. BY Stefan Norris

The Arctic is one of the regions on earth where climate change will be seen early, and most dramatically. Arctic indigenous communities are already noticing some of these changes: warmer winters, early spring breakup, and thinner than usual ice. This traditional knowledge echoes the scientific evidence:

  • Air temperatures in the Arctic have on average increased by about 5°C over the last 100 years.
  • Arctic sea ice extent decreased by approximately 3 per cent per decade between 1978 and 1996.

The results of climate modeling of vary in detail, but all show a clear trend towards an overall warming in the Arctic, and a resulting melting of the sea ice. The models suggest that by 2080, arctic sea ice will completely disappear during the summer months.

These are dramatic and rapid changes in an ecosystem defined by being frozen. A slight shift in temperature, bringing averages above freezing, will completely alter the character of this region, from one of ice covering the seas and permafrost stabilizing the ground, to one of open water and large tracts of land simply melted away. The consequences for humans and animal species, such polar bears, that are adapted to the current Arctic ecosystem, will be severe.

“New information indicates the greatest future challenges to the conservation of polar bears may be ecological change in the Arctic as a result of climate change…” (Polar Bear Specialist Group, 2001).

In the southern range of polar bears, for example the Hudson and James Bays of Canada, sea ice is already melting earlier in the spring and forming later in the autumn. The time bears have on the ice, storing up energy for the summer and autumn when there is little available food, is becoming shorter. As the periods without food are extended, the overall body condition of these bears decline. This is particularly serious for pregnant or nursing females, and young cubs. In Hudson Bay, scientists have found the main cause of death for cubs to be either an absence of food or lack of fat on nursing mothers.

”For every week earlier that break-up occurs in the Hudson Bay, bears will come ashore roughly 10kg lighter and thus in poorer condition. With reproductive success tied closely to body condition, if temperatures continue to rise in response to increases in greenhouse gas emissions and the sea ice melts for longer periods, polar bear numbers will be reduced in the southern portions of their range and may even become locally extinct” (Dr. Ian Stirling, Polar bear scientist).

The local and indigenous peoples of the Arctic are dependent upon a healthy and well-functioning ecosystem for survival – both physically, as much of their nutrition is derived locally from harvesting of natural resources; and culturally, as the traditions tied to living in a land that is frozen most of the year define their way of life. Any development that is to be culturally and ecologically sustainable in the Arctic is dependent upon maintaining a healthy ecosystem.

Large carnivores are sensitive indicators of ecosystem health and can be used to define the minimum area necessary to preserve intact ecosystems. WWF has identified the polar bear as a unique symbol of the complexities and inter-dependencies of the arctic marine ecosystem as it works toward its goal of preserving biodiversity for future generations

Stefan Norris
WWF Arctic Programme

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