Climate change: Rising sea levels, storm surges, ‘slow-motion disaster’ on Canadian coast

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The tide is rising, the sand is shifting, and the coastline is crumbling. Canada’s coastal regions are wondering what the future holds as research warns of rising sea levels and accelerating erosion caused by climate change.

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“Coastal living is part of our economic, social and cultural fabric. It’s how people live,” said Chris Hauser, Professor of Environmental Sciences at the University of Windsor and member of the University’s Coastal Studies Group. said: “When we see some of these coastal areas eroded or further affected by rising sea levels and storms, it’s going to be a very difficult time.”

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Communities on Canada’s east and west coasts face the risk of falling below high tide as water levels rise incrementally. According to the Intergovernmental Panel on Climate Change report released last year, the rate of global sea level rise is accelerating, with sea levels rising about 20 cm since the beginning of the 20th century.

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John Craig, professor of geosciences at Simon Fraser University in Burnaby, says even a few millimeters can make a difference, especially if the effects are exacerbated by violent storms like Fiona’s that hit the Canadian Atlantic in September. increase.

“It’s a slow motion disaster,” he said. He noted that Fiona caused a lot of erosion. “And it’s permanent. Once it’s done, that’s it.”

On the other side of the country, municipalities such as Richmond, with a population of over 250,000, live with “a threat in front of them,” he said. The region is home to Deltaport, one of Canada’s most important export facilities, as well as Vancouver International Airport and other critical infrastructure worth trillions of dollars that can easily be abandoned or relocated. You cannot

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The most pressing solution in place is to raise new buildings along the coast by one meter to allow for expected sea-level rise, but that is a temporary fix, he said.

“We are just postponing the problem,” says Clague.

Hauser said scientists hadn’t “properly calculated” how much land was lost as sea levels rose because there was a combination of factors involved. He said that while rising water is taking over land, there is also the threat of flooding and erosion.

“A lot of the erosion around Canada has nothing to do with sea level rise. But it really has to do with sediment imbalance,” he said.

As the sea moves in, the ecosystem adapts by moving towards land. That’s fine as long as there’s space to move around, but human communities aren’t very mobile. People may start abandoning coastal communities affected by changing conditions, he said.

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Almost half of the world’s sandy beaches will be at risk of extinction by the end of the century, according to a study published in March 2020 by the European Commission’s Collaborative Research Centre, due to rising greenhouse gas emissions. … apparently …

The paper suggests that Australia stands to lose the most, followed closely by Canada. Models show that Canada will lose between 6,400 and 14,400 kilometers of sandy beaches by the year 2100. Canada’s total coastline is approximately 243,000 kilometers.

Adam Fennec, director of the Climate Lab at the University of Prince Edward Island, said the state’s 1,260 kilometers of coastline are at significant risk of erosion. According to research, the island he eroded at an average rate of 0.28 meters per year between 1968 and 2010.

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Fenech used that data to show how the state’s coastline will change over the next 80 years. According to his calculations, by the end of this century he will have over 1,000 homes, 146 commercial buildings, over 40 garages, 8 barns, 7 pavilions, 17 lighthouses and 45 kilometers of roads. It is at risk of being lost by coastal erosion.

The island is “just made” of sand and sandstone, Fennec said, not a “very hardy” place to begin with. Add in climate change and things get worse.

“As sea levels rise, water temperatures warm and sea ice disappears, it acts as a buffer against storm activity. It works against you,” he said.

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“The islands aren’t going anywhere fast. It’s still 10,000 years away from them. But there are places where we’re losing 1 to 5 meters of coastline each year.”

Kate Shellen, a professor at Dalhousie University’s School of Environmental Studies, said the edge of Canada was higher and drier before the glacier retreated.

The geological force is still balancing its weight, and the coastal edge is slowly sliding back into the water, she said.

Imagine a heavy person sitting in the middle of a waterbed with two smaller people on either side, says Sherren. “When that big guy gets up, the last guy actually falls down.”

And that’s what’s happening in central Canada during this post-glacial period, she said.

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Fenech called PEI the proverbial canary in the coal mine for being at the forefront of the impacts of climate change. But it will also help scientists and governments make leaps and bounds in understanding where and how best to adapt to and live with climate change, he said. .

Hauser said coastal areas hit by major storms need to rethink how they rebuild and whether certain areas are off-limits.

“Are we going to enforce a different type of beach building and armor? Or… are we going to allow the area to be in water?”

Hurricane Ivan, which hit Florida’s coast in 2004, was considered a once-in-a-century storm, he said.

“What happened was, right after the hurricane, all the houses were demolished and the roads were completely torn up, and then house prices actually went up. I believed it would be safe for 99 years,” he said.

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“There is a problem with the way people perceive and understand science, the way they understand probability.

Erosion phenomena seen in Prince Edward Island and Northumberland, New South Wales, show that the landscape will change dramatically after Fiona hits the area this year, Schellen said.

“It probably won’t go away in 20 years, but it will look a lot different. And that’s the term of the mortgage.”

People need to understand that coastlines are dynamic, not static, she said.

“The floodplain belongs to the river, the beach belongs to the sea,” Schellen said, recalling a phrase she once heard. increase.”