Monique Keiran: We can’t escape effects of rising sea level

Some day, our hilltop house could be waterfront property. It won’t happen soon — certainly not in this century, and maybe not even this millennium. However, if global warming continues, the surf may indeed break at the bottom of our driveway.

Nature Boy can’t wait.

article continues below

When I point out the timelines don’t work with his schedule, he says: “Did you ever in a million years think we would live in a house that’s worth what our house is worth now?”

If he’s that excited about sea level rising in the next 200 to 1,000 years, it’s just as well he wasn’t around 11,000 to 13,000 years ago. Bison fossils on the San Juan Islands and Vancouver Island suggest lower sea levels at the time created a land bridge from Victoria to the mainland.

The link would have allowed plants, bison and other animals to spread here from the mainland at the end of the last ice age.

But the ice age is over and climate is changing again. Last year marked the 36th year in a row in which global temperatures outpaced the 20th-century average. It was also the 10th warmest year since 1880, when people first started recording temperature.

Not that we noticed it around here. Well into last summer, Canada’s far west saw cooler-than-usual temperatures. And then, August and September happened — and, yes, it finally warmed up.

As we keep hearing, persistently warmer average temperatures have consequences. Scientists now predict sea level will rise by as much as one, possibly two metres by 2100. The increase will be due to the oceans warming and the Greenland and Antarctica icesheets — the two largest branches of the World Bank of Ice and Snow — gradually melting and releasing frozen assets.

Canadian content in the seawater mix will be minimal. Scientists recently announced that glaciers in Canada’s high Arctic will likely contribute a mere 3.5 centimetres, or 12 trillion cubic metres, of water to this century’s total sea-level increase. That amount equals about 20 per cent of the water frozen in the Arctic glaciers, the World Bank of Ice and Snow’s third-largest branch.

A one-metre rise in sea level will not, on its own, swamp much of the capital region. Thanks to high-bank topography, many of us have some built-in protection. However, climate-change risk assessments done for Victoria and Saanich last year suggest a one-metre increase would extend the reach of high tides, and combinations of high tide, the expected increase in winter rainfall and more frequent intense storms and storm surge could overwhelm drainage systems and cause flooding, erosion and other damage.

As a result, municipalities are turning their attention to updating strategies and upgrading infrastructure to handle the expected seasonal, periodic deluges. As well, at a joint meeting last November, Saanich and Victoria councils and the Capital Regional District agreed to produce a regional map of flood-vulnerable areas and to draft a model bylaw to assist in their management.

That’s just a start, but overall, I’d say we’re getting off lightly. A B.C. government report released in December estimates upgrades to Metro Vancouver dikes and other flood protection over the coming decades will cost $9.5 billion. With more than 220,000 people living at or below sea level and $55 billion in infrastructure and buildings at risk, Metro Vancouver is the Canadian urban region with the most to lose as sea level rises.

Nature Boy, who grew up on Sea Island where airplanes now land every few minutes, reports having been able to tell when the tide was in because it made his lawn squidgy. Imagine how higher sea levels and higher tides would affect those lawns.

The predictions focus primarily on the next 90 years, but the World Bank of Ice and Snow won’t stop melting on New Year’s Eve 2100. That’s when Nature Boy will start taking bets on when he might be able to launch his kayak from our driveway.

It’s all about timing and your preferred method of transportation. In 1,000 years, Nature Boy might be able to kayak from home, but 12,000 years ago, he could have walked to the mainland.

Read Related Topics

© Copyright Times Colonist

Find out what's happening in your community.