Rising sea levels and storm surges are taking a bite out of Canada’s 243,000 kilometres of coastlines from the Atlantic to the Far North to the Pacific, researchers warn.
The phenomenon is nationwide but affects regions in different ways, notes Jean-Pierre Savard of Ouranos, a consortium of scientists and specialists who study climatology across North America.
Savard, who recently returned from an international conference on coastal erosion in Quebec, says the phenomenon was raised by researchers from coast to coast, and overseas as well.
“The overall picture is that all government organizations involved in the management of coastal zones are concerned because climate change has a global effect that leads to greater erosion and risks,” he said.
Across the North the coasts are threatened by the rapid melting of the permafrost, Savard noted, while melting ice in general exposes coastlines.
“This is a big problem across the Gulf and the Arctic because the ice protects the coastline, as it shrinks it becomes an agent of erosion, becoming more mobile and letting more waves hit the coastline, increasing erosion problems,” Savard explained.
The manifestations of land erosion vary, he said. “In the Bay of Fundy the problems aren’t the same as in British Columbia, which is more exposed to tsunamis and problems of this nature.”
In tiny Souris, P.E.I., people who live in houses perched above a sandstone cliff have lost three metres of land in the last decade. Some of those homes are now just three metres from the edge, said Deputy Mayor Denis Thibodeau.
“There’s been erosion since the beginning of time, I guess, but . . . there’s not much room left in some cases,” Thibodeau said.
Get daily National news
On British Columbia’s Queen Charlotte Islands, the same amount of land is gobbled up annually.
Climate researcher Ian Walker of the University of Victoria says Canada has the longest coastline in the world and over 80 per cent of it is submerging due to sea level rise. But even areas where the sea level is stable are at risk, he says, because of the greater frequency of storms, particularly on the Pacific coast.
“The greatest concern is areas that are highly developed. Richmond is at or below sea level and it’s one of the most densely developed and developing areas in greater Vancouver.”
“The airport which will serve the Olympics is at or below sea level and is protected by dikes.
“You have the combined increased sea level rise, increased storminess, increased flooding of the Fraser River, increased development causing the sinking of the land, all culminating into one highly developed, economically rich area.”
Walker, who authored a study on climate change and sea-level rise on B.C.’s Graham Island and the Queen Charlotte Islands – also called Haida Gwaii – cautions that erosion is a natural process not always linked to climate change. But he adds it tends to accelerate in areas that are already prone to erosion.
On Haida Gwaii, “we’re seeing more extreme storm events, more storm surges superimposed on sea level rise that would be accelerating sea level erosion,” he said. “There are sites we have been monitoring for 15 years and we have seen rapid rates, averaging one to three metres a year along that coast.”
He lists other areas at risk across the country: “The Mackenzie Delta in the Northwest Territories, Prince Edward Island, portions of Nova Scotia and New Brunswick, Halifax harbour, Charlottetown harbour – these are all areas that are subject to fairly rapid sea level rise and in some cases, not all, subject to enhanced erosion,” he said.
The problem, says Walker, is that “we’ve developed a lot of our houses and communities and infrastructure on coastlines or on flood plains for historic reasons, for esthetic reasons, cultural reasons that in the face of climate change put us in increasing hazard and . . . increasing risk of economic losses.”
In Tuktoyaktuk, N.W.T., the rising Beaufort Sea is eating away at the land there, too.
Norm Catto, a geography professor at Memorial University in St. John’s, N.L., says the surprisingly delicate North is feeling the combined effects of storms, high sea levels and warmer summers.
“Most of the area affected is permafrost, so you have frozen sediments and lenses of ice (that) have very little resistance when the waves strike.
“When you couple that with the general warming conditions that we see in the area . . . it accelerates erosion. And if the amount of ice in the Beaufort Sea is reduced . . . the wave action is able to act on the coast for a greater period of time.”
In the Gulf of St. Lawrence, Magdalen Islands Mayor Joel Arsenault worries about the islands’ connecting road network, which is built on sand dunes and is being eaten away.
A report on the vulnerability of Gulf communities like Arsenault’s was completed by Ouranos last month for the Quebec government.
It found coastal erosion was a growing problem, caused in part by rising sea levels and shrinking ice packs leaving coastlines more exposed. Erosion was also aggravated in recent years by intense precipitation.
Catto cautions that areas that are prone to floods will see worse flooding as sea levels rise.
“We have a number of communities . . . where rising sea levels are going to cause difficulty,” he said. “This has happened once; it can happen again. So how are we going to cope?”
Comments
Want to discuss? Please read our Commenting Policy first.