Scientists raise alarm over rising sea level threat
Simon Fraser University geology professor John Clague says the world’s oceans could rise more than a metre in the coming decades, while a respected atmospheric scientist suggests five metres could be in the cards by 2080.
James Hansen, adjunct professor of Earth and Environmental Sciences at Columbia University, spoke at last weekend’s annual meeting of the American Association for the Advancement of Science, where forecasts for the world’s oceans indicate a wide range of possibilities, with a rise of as little as 30 centimetres to perhaps a metre or more this century.
But Hansen believes that unless changes are made, by 2080, the world could reach a tipping point that will see the oceans rise by five metres.
Although Clague doesn’t believe that will be the case, he said Hansen has strong credentials.
“He’s not a flake,” Clague said, noting that Hansen predicted 30 years ago that greenhouse gases would have an impact on the climate.
Hansen predicts that if the world continues on its path, rapid melting in Greenland and Antarctica would result in catastrophe for coastal communities.
“In the case of Richmond, it’s clear it will be defended. That’s feasible for a metre of sea level,” Clague said. If the rise is five metres, that couldn’t be defended.
The city is currently studying a $200 million dyke upgrading plan to deal with sea level rise of about a metre.
Predicting precisely how much oceans will rise is “hellishly complicated,” with scientists around the globe competing to find the most accurate figure through computer modellng.
But all those models are pointing in the same direction, Clague said.
“It’s really not so much scientists are getting brighter, but we have more sophisticated tools,” he said.
“I find it hard to accept Jim’s (James Hansen’s) point of view, but I respect him tremendously.”
So what’s a Richmond homeowner to do?
Clague said they should insist that their local political leaders develop a plan that’s open to public airing and discussion.