Q&A

Rising sea levels a threat to Metro Vancouver, prof says

"These are your great-grandchildren that will have to deal with this problem. Perhaps your grandchildren," Simon Fraser University earth sciences professor John Clague said.

Rising sea levels and shoreline erosion need to be dealt with over course of century

Boundary Bay residents and city staff pile up sandbags in anticipation of king tides back in January. An SFU professor says rising sea levels will be a challenge for all of Metro Vancouver this century. (Jesse Johnston/CBC)

People call him "Dr. Doom," but Simon Fraser University earth sciences professor John Clague says the Lower Mainland needs to prepare for the effects of climate change in the region.

Clague says sea levels are already rising, and unless action is taken now, the costs could be massive in the coming decades.

He says sea level rise and shore erosion could cost the region billions, and some people could lose their homes.

Ahead of a panel discussion on the topic, Clague spoke with On The Coast host Stephen Quinn about how rising sea levels will impact the Lower Mainland.

What kind of sea-level rise are scientists predicting for this region?

Since Vancouver was established, sea levels have risen about eight inches, 20 centimetres. It's ramping up. We're seeing an acceleration in sea level rise.

The best guess [by the end of the century] is 40 centimetres to one metre. It has huge consequences for people living in low-lying areas on the South Coast.

And what are those consequences?

There are two processes in operation here. One is coastal erosion. You can think of our soft cliffs here, like Point Grey. These would be more vulnerable to erosion, to retreating back under wave impact under a higher sea level regime.

Perhaps of even greater concern is the possibility of inundation, of flooding during severe storms. Sea levels rise very slowly, but it's a worry when you have a "perfect storm" of higher sea levels, stronger storms, winds blowing.

We have this phenomenon called king tides that happen twice a year. At those times, tides are extremely high, and there's some protection that's already taking place at Jericho Beach and West Vancouver now to deal with that.

A pump station in Richmond. That city, being so low-lying, faces severe risks due to rising sea levels. (Google Streetview)

Are we talking about the kind of erosion that could put people in danger or their property in danger?

We saw this in Hurricane Sandy. It's remarkable how far in those hurricane-force winds and waves can force the shoreline inland. That's conceivable in a regime like later in this century when sea levels might be many tens of centimetres higher than it is today.

Is shoring up dikes enough for a community like Richmond?

We can engineer solutions for modest amounts of sea level rise. Very expensive, is the problem.

There was a study for the provincial government that found if we see sea level rise a metre by the end of the century, for the Metro Vancouver region, we're looking at something on the order of $9 billion.

That's the big problem: we can kind of cope with it, but at a huge cost. And the question then becomes, who's going to pay for that?

John Clague is a professor of earth sciences at Simon Fraser University.

We might not see the serious effects of this for decades. Do people tend to take this seriously at this stage? Do they accuse you of being a fearmonger?

Well, I have been referred to as "Dr. Doom." It's not fearmongering. It's going to play out. We have time.

The models suggest it will ramp up toward the end of the century, but these are your great-grandchildren that will have to deal with this problem. Perhaps your grandchildren.

With files from CBC Radio One's On The Coast


This interview has been condensed and edited for length and clarity. To hear the full interview, click the audio labelled: Rising sea levels a threat to Metro Vancouver, prof says