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Climate change

The North


The Canadian Arctic is on the front lines of global warming. The North and its residents have been aptly described as the “early warning system for the entire planet.” Indeed, temperatures in the Western Arctic are among the fastest rising on Earth. Over the past 40 years, average temperatures in the Mackenzie Basin have increased by 1.5°C; by the second half of the 21st century, scientists predict temperatures in the Northwest Territories will be at least 5°C warmer than they are now.

Sea ice
The very essence of the land of snow and ice is melting away. The polar ice cap has been shrinking at a rate of nine percent per decade since the 1970s, according to recent NASA estimates. If this trend continues, some scientists say the summer sea ice cover may completely disappear by the end of the century. Others say it could happen as early as 2050. Meanwhile, an ancient ice shelf tore away from Ellesmere Island in 2005, creating a 66-square-kilometre island. Scientists suspect the breakup was caused by global warming.

Sea ice in the Arctic is not only shrinking in size, it is getting thinner. More open water means stronger waves lapping at the shoreline and causing destructive erosion, particularly along the Beaufort Sea coast. Erosion and rising sea levels are already threatening Tuktoyaktuk, a major shipping port in the Canadian Arctic. Rising sea levels:

Canada’s coastline, the longest in the world, will be affected by rising sea levels, caused by the expansion of ocean waters as they warm and melting glaciers and ice caps. Estimates vary widely, but the global sea level is expected to increase by up to 90 centimetres by 2100. In the Arctic, the Beaufort Sea coast, including parts of the Mackenzie Delta and the Tuktoyaktuk Peninsula, will be particularly affected by changing sea levels, as well as decreased ice cover and melting permafrost.

Permafrost
Much of the land in Canada’s northern reaches is underlain by permafrost, ground that remains frozen year-round. In recent years, melting permafrost has altered the landscape, turning parts of the hard tundra into swampy, shifting ground and increasing the risk of landslides. This is having a serious impact on many aspects of northern life, from the safety of ice roads to the instability of buildings, airstrips, pipelines and municipal water supply.

Tuktoyaktuk on the brink
One of the Canadian communities most vulnerable to climate change is Tuktoyaktuk, N.W.T., a hamlet of 1,000. The transportation hub for the Western Arctic sits on a peninsula at the edge of the Beaufort Sea. It has been subject to the sea’s erosion since its establishment in 1934. Between 1935 and 1971, the coastline has retreated by more than 100 metres in parts of the community. More recently, warmer temperatures are melting the sea ice, increasing the rate of erosion and the potential for flooding. In severe weather, parts of Tuktoyaktuk already get submerged.

The sea is eroding a gravel spit erected in 1996 to protect the townsite from flooding. This is the third attempt to preserve the shoreline since 1976. Some of the hamlet’s buildings, such as the curling rink and the school, have already been destroyed by erosion; others have been moved. Keeping the sea at bay is costly and increasingly difficult: the community may eventually be forced to relocate.



Synopsis

Ayles ice shelf This animation starts with a view of the earth from space, and gradually zooms in on the northern coast of Ellesmere Island, Nunavut. A timeline bar illustrates the passage of time from April to August, 2005. As the picture gets closer, the gaps and open water between the ice floes become more evident. Animation shows the Ayles ice shelf in red as it breaks away from the shore on August 13, 2005.


Content (Narration)

Scientists estimate that since 1900 approximately 90 per cent of ice shelves on Ellesmere Island, Nunavut have broken up and floated away.

On August 13, 2005 an ice shelf at least 3,000 years old, broke away from the island, marking the largest ice shelf collapse in the last 25 years.

A total of 87.1 square kilometres of ice was lost, the largest piece measuring 66.4 square kilometres - roughly the size of 11,000 football fields. The Ayles Ice Shelf collapse signals changes in the Arctic. As of 2006, only five ice shelves remain in Canada.



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Quiz :

Global sea levels are expected to rise how much by 2100?

30 cm
50 cm
90 cm