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Bowen's beaches, docks and cliffs made of sediment susceptible to rising seas

The sea in B.C. is expected to rise by as much as half a metre by 2050
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Bowen's shorelines will be susceptible to the rising seas of coming years. Photo by BRONWYN BEAIRSTO

Climate change has been evident for decades and it's starting to become ever more apparent with the increasingly discernible threat of sea level rise, especially for those in coastal communities.

Bowen is mostly comprised of high, rocky slopes so in effect, the island is less vulnerable to sea level rise than areas such as Richmond, Surrey and the Fraser Valley. However, it will see changes from the rising tides and storm surges.

Climate change affects sea level rise in two ways.

First, through thermal expansion, when the ocean warms up and the water expands, essentially taking up more space in the seas. Secondly, ice caps situated on land melt, raising water levels all around the world. The ice caps within the ocean itself take up the same space when melted so don't pose the same threat as land-based ice.

The biggest impacts sea level rise will have on Bowen is on the beaches, docks and cliffs made of sediment, according to Bob Turner, a longtime resident and former mayor of the island.

Turner was a research scientist with the Geological Survey of Canada. He retired in 2014 and in the last decade of his work was doing public education. He looked at natural hazards, including landslides, earthquakes, mudslides and sea level rise.

Turner said there has been talk of sea level rise for about 25 years. "Very early on it was understood that a warming climate would lead to sea level rise. The question has always been, how fast," he said.

The rate at which the oceans will rise is dependent on many factors, including extreme weather events such as flooding, extreme storms and erosion. According to Educating Coastal Communities About Sea-Level Rise (ECoAs), which held a workshop earlier this month on the island, the sea rises at a rate of roughly 2.3mm per year, but that number has doubled in the last two decades.

For B.C. in particular, it is projected that the ocean will rise as much as half a metre by 2050.

Turner spends a lot of his time paddling the shores of Bowen Island and Howe Sound, which has given him a first-hand sense of the potential impacts of the rising sea levels.

Sea level rise is not an event that happens overnight but Turner still implores everyone to be aware of it and for the community to have plans in place to prepare for it.

Turner said that there is good news. Marine wildlife, specifically marine mammals, have shown a significant increase in Howe Sound waters the last eight to nine years. When he moved to Bowen in 1989, Turner said the oceans were a very quiet place. But when the herring returned to Howe Sound, marine life followed.

On the backdrop of sea level rise, Turner said that the community of Bowen should be aware of the blessing that the marine environment brings and know how to protect it by maintaining healthy shorelines. "We have an obligation to really think carefully about how our shorelines contribute to this marine recovery and what we can do given sea level rise to ensure that our shorelines are sources of marine recovery."

Having healthy shorelines is vital for preparing for the inevitable sea level rise that is expected to occur within the next few decades, according to DG Blair, executive director of Green Shores, a program out of the Stewardship Centre for B.C. Green Shores sets a design standard for shoreline projects. It encourages naturally designing the shorelines, protecting the wild habitat and taking into account the interaction between the shore and the water.

"Shorelines are very, very popular places to live and play so the cumulative number of small residential properties can add up to a huge impact," Blair said.

When a wave comes in at one metre high, when it hits a natural shore, it stays at one metre. But that same wave comes in and hits a rock armoured wall, it goes up five to 10 times its height. Armoured shores also create coastal squeeze, which in turn causes habitat loss.

Bowen councillor David Hocking is the Metro Vancouver director for Bowen Island and a member of the climate action committee. He worked with the Suzuki Foundation for 10 years. He said that it's hard to predict the rate at which sea level rise will occur because of all the other factors that come into play, including storm surges, climate change and whether society takes any strong action or not. "But regardless of all that we're still going to see sea level rise because there is already so much heat baked into the system," he said.

Gary Ander, mayor of Bowen Island, said that the rising sea levels are definitely an issue

"We can't control it but we are definitely conscious of it because it's an absolute truth," Ander said. He said that they don't have any immediate plans in place, but that they are aware of it and they do have a committee formed for climate change which keeps an eye on everything. Educating the community is also a component of action, including workshops such as the one earlier this month.

The biggest concerns for Turner, Hocking and Ander are the increase in storms that the island has been seeing, specifically the debilitating storm that occurred this past winter where the ferry was cancelled for hours at a time. Such situations are where Bowen Island is most vulnerable.

"We expect to see harder and more surprising storms," Hocking said.

With sea levels on the rise, when a storm hits, it has a greater impact because the waters will be able to reach further inland.

Turner said that if Bowen could take a page out of the communities that are more vulnerable to sea level rise.

"Their circumstances are different than ours in general but I think it we want to learn about how to carry on a conversation about sea level rise we can learn from those communities where the stakes are much higher."

This article originally appeared here.