By Martin van den Hemel
Staff Reporter
Apr 28 2007
Climate change due to global warming places Richmond at risk of flooding as the sea level rises, warns a United Nations report that’s expected to be released next Friday.
The report by the United Nations Intergovernmental Panel on Climate Change names Richmond and Charlottetown, P.E.I., as vulnerable centres in Canada, according to Don Forbes, a research scientist with Natural Resources Canada. Forbes is one of the lead authors of the chapter in the U.N. report—expected to be released during a press conference in Bangkok on May 4—that refers to Canada.
Some may question the need for concern when the sea level is only expected to rise a few dozen centimetres over the coming decades, Forbes said.
The danger comes from the increased frequency of flooding, he explained.
“As sea level comes up, the frequency of flooding to a given level increases,” he said from his office in Dartmouth, N.S.
For example, in Charlottetown the sea level is expected to rise 32 centimetres per century.
“In the first half of the 20th century, a 1-in-20-year flood at a particular level...(would) just with sea level rise...become a 1-in-3.3-year event. So the same kind of thing goes on in the Fraser River Delta area.”
Forbes said the latest findings still leave unanswered questions about major glacier melting, in Greenland, for example, which could have catastrophic worldwide consequences in the centuries to come.
“The latest report does leave that question hanging although in general the estimates of sea-level rise are better constrained than they’ve ever been before with that question mark...I think realistically, depending on which scenario and which model you use, you’re looking at an upper limit of about 60 centimetres.”
What must also be factored in, Forbes said, is land subsidence, the dropping of the ground level due to settling and other factors over time.
Richmond’s dykes have been designed to a statistical analysis of what water levels have been historically, and that planning mindset needs to change, Forbes said.
“The change in thinking that has to happen is that the engineering profession has to think in terms of the climate, the water level statistics not being constant, but being on an upward trend.”
Another adaptation to the environment is for new houses to be built higher, he said.
The key is good communication between the scientific community, those who make the plans, the decision-making politicians and the public.
University of Western Ontario professor Gordon McBean said Richmond’s dykes need to be fortified and raised to account for a gradual sea level rise of up to 60 centimetres, or nearly two feet, this century. McBean chairs the International Scientific Committee for the World Climate Research Programme.
“That should be part of their planning premise. It’s called an adaptation strategy,” the former Lower Mainland resident said.
News of the United Nations report broke April 20, the same day the city held a press conference to reassure Richmond residents that the city is prepared for flooding threats.
McBean said there is a tendency to plan for the future based on the past.
“Whatever you do, don’t plan that the climate of the future is the same as the climate of the past.”
But rising sea levels shouldn’t be the sole focus of concern, he said.
“As sea level rises, we also expect to have more storminess” and storm surges, he said. “This is not a panic, run-for-the-hills scenario. In my view, they are manageable (risks) in the economic...situation that Canada is in.”
Richmond, unlike some parts of the world, is fortunate in that it can tap into vast financial resources to implement plans based on the latest science and adjusted to advances in scientific knowledge.
“The island state of Tuvalu (east of Australia) is largely going to be abandoned because they don’t have economic and technical capacity to build dykes and things and so they’re negotiating moving the whole population to New Zealand as basically environmental or climate change refugees,” he said, adding that the Maldives in the Indian Ocean is also at serious risk.
Prior to the devastation that hit New Orleans and the Gulf of Mexico states in the U.S. in August 2005, the scientific community issued warnings and recommendations that were largely ignored by government, McBean said.
Too much of the current focus on global warming has been on efforts to reduce harmful emissions, but McBean said what’s been forgotten in taking immediate steps to adapt for environmental change.
“The reality is that for the next few decades, the climate will change regardless of which emission reduction strategy you put in place and we should have an adaptation strategy driven by the best scientific input...”
Terry Crowe, manager of policy planning for the City of Richmond, said it will be extremely costly over the coming decades to protect the city from flooding. But the city is tapping into the latest science and preparing for the climactic changes to come.
Not only are dykes going to be built higher, but they may also need to be widened, he said.
Despite the annual steps to maintain, test and reinforce the dykes, the cost over the coming decades has been estimated at $91 million. A proposed mid-island dike could cost $16 million.
Crowe said a good strategy involves a range of things, and the city is, among other things, requiring that new homes be built a little higher than normal, and adjusting entire neighbourhoods, such as West Cambie, when it’s appropriate.
All of this planning is made with the underlying principles of safety, prevention, sustainability, cost effectiveness, partnerships/cost sharing, and co-ordination, he said.
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