People living in Tuktoyaktuk, NWT, know what it is like to lose ground. Ever since the community was founded in 1934, storms blowing in from the Beaufort Sea have eroded the land on which the coastal community was built.

Erosion has destroyed a curling rink, caused a school to be abandoned and a RCMP building to be moved. In 1993 a storm eroded away 13 metres of Tuk's coastline and destroyed more than half of the sandbags protecting the community.

Even though no permanent communities are threatened by erosion in the Yukon, we are also losing ground. Every year between one and two metres of our coastline erodes away, and there are concerns that global warming could possibly increase this rate.

The Geological Survey of Canada (GSC) has been tracking erosion along the Beaufort Sea for the past 20 years, increasing its efforts when interest in oil development is high. Scientific work on erosion is on the rise again because of concerns about the effects of global warming and a renewed interest in oil and gas development in the North.

Steve Solomon, a GSC coastal geologist, has been working along the Beaufort for the past ten years, and recently completed a map showing the coastline between the Yukon-Alaska border and the tip of the Tuktoyaktuk Peninsula.

While the map will help to show which areas are most prone to erosion, Solomon says much work remains to be done on understanding how erosion works in the North.

Most of the scientific work on coastal erosion has been done in more temperate climates where the pounding of waves removes materials from cliffs and beaches. Conditions along the Arctic Ocean are much different, as the sea is frozen for much of the year and the land itself consists of a ice mixed with frozen sand, gravel and mud.

Along the Beaufort Sea, both permafrost in the ground and sea ice in the ocean change the shape of the coastal lands. Sea ice can scrape and gouge the seabed, even working like a bulldozer to move sediment up onto the shore.

Sea levels are expected to rise with global warming, and this could cause major problems in areas where the coastline is heavily developed. But some scientists think that northern oceans may not rise as much as those further south.

"The primary cause of climate change induced sea level rise is thermal expansion of the upper surface of the water. The water gets less dense as it warms and expands. Arctic waters will not warm to the same extent as oceans further to the south. This, along with several other factors contribute to lower predictions of sea level rise in the North," says Solomon.

But much of the erosion along the Beaufort coast is caused by storm surges, and climate change could increase the number of these events. Strong winds, which are most often blowing from the northwest, create the surges, which are usually accompanied by high waves.

Surges form as the wind pushes the surface of the water ahead faster than the water can drain back. The longer the stretch of open water, the higher the surge and the larger the waves, and global warming could result in more open water in the Arctic Ocean.

"With climate change the most critical effect could be that the amount of sea ice will decrease considerably," says Solomon.

The water could also stay open for longer during the year because of global warming. "The length of the (open-water) season could extend into fall when more storms occur anyway, so the chance of a big storm occurring when there is a lot of open water will increase, says Solomon.

"Maybe now you get a major storm once every ten years. In the future you may get one every five years. It's a crap shoot in terms of probability."

Any company investing large sums of money in a pipeline or oil refinery will not want to play the odds on erosion, and that is why the GSC is trying to predict which areas are most suitable for development.

Parts of the Mackenzie Delta are eroding at rates greater than ten metres per year. The rate is lower further west along the Yukon coast. The reason for the difference is that the Delta coast consists of very low tundra cliffs composed of frozen mud and peat whereas along the Yukon, the coast is high and consists of coarser materials.

"If you build a gas-processing facility on the coast, you have to site it so that it will not be endangered by a severe storm or a series of storm years," says Solomon. "If a pipeline comes ashore it will be buried for a good portion of the way, but the information on erosion could affect the length of pipe which must be buried or how deeply it must be buried."

"In effect what we are trying to do is give a scientific basis for development. We cannot just look at the past as a key to the future because of the uncertainty induced by climate change," says Solomon.

For more information on coastal erosion in the North, contact Steve Solomon at steve.solomon@nrcan.gc.ca.