Get used to weather extremes, expert says

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This article was published 22/06/2013 (4518 days ago), so information in it may no longer be current.

Pardon the pun, but scientific talks about water, climate and changing hydrological cycles tend to be a bit dry.

It was anything but this week as water and climate expert Robert Sandford delivered a keynote address at a Winnipeg workshop discussing water management.

As Sandford spoke on the science of why weather patterns are becoming more turbulent, resulting in extreme precipitation events, parts of his hometown of Canmore, Alta., were literally washing away.

Later that day, parts of Winnipeg were deluged with a cloudburst that within minutes had overwhelmed the storm sewers and flooded streets and businesses, forcing the famous new IKEA store to close early and dismiss customers.

You could sum up Sandford’s 30-minute presentation in four words: get used to it.

Sandford works for EPCOR, the City of Edmonton’s water utility, chairing the Canadian Partnership Initiative in support of the UN’s Water for Life Decade project. His job is translating the science of climate change into language the public and policy-makers can use for meaningful adaptation.

The science links this week’s weather events directly to global warming. Those melting polar ice caps we’ve all been reading about don’t just affect what happens to the polar bears; researchers are gaining new knowledge about the important role the world’s cold spots play in our weather.

“Ice plays a critical role in modulating the temperature in the Earth’s atmosphere and its oceans,” Sandford said. “Polar ice is now seen as a thermostat that governs major weather patterns globally and regulates sea level.”

Arctic sea ice is melting. Last summer, the ice disappeared from an area two million square kilometres larger than all of Canada’s land mass. The reduced duration and extent of snow cover in the North is reducing the temperature gradient between the polar poles and the tropics. That’s weakening and destabilizing the jet streams, those fast-flowing, relatively narrow air currents that form on the boundaries of air masses with different air temperatures.

Warm and cold fronts are now showing up in odd places and sticking around longer, causing floods and droughts “of a magnitude we are poorly equipped to manage.”

“What we are seeing in North America is not so much a warming as a destabilization of historic weather patterns,” Sandford said. “People are complaining the weather is all over the place. Well, it is.”

NASA records show between 1951 and 1980 extreme hot weather covered less than one per cent of the Earth’s surface. Now, extreme temperatures cover about 10 per cent of the Earth’s surface. It is estimated 300 glaciers have disappeared from the Canadian Rockies between the early 1800s and 2005.

“Warming is causing the post-glacial hydrological wealth of Canada to change form. The water is not disappearing; water doesn’t do that. What is happening is the liquid water is moving to a different place in the hydrosphere,” he said.

“One of the places it is going is into the atmosphere, where it becomes available to fuel more frequent and intense extreme weather events.”

In short, Sandford says, the old math about how to manage water — and extreme precipitation events — no longer works, which might explain how a shower lasting only a few minutes would overwhelm the city’s storm sewers or why thousands of people in Alberta have suffered untold losses and displacement.

The implications for a province such as Manitoba are ominous, given its geographic placement as the drain at the bottom of the bathtub for two major North American rivers spanning multiple jurisdictions.

“It appears the Central Great Plains region may have passed over an invisible threshold into a new hydroclimatic state, which if not properly managed, could over time bankrupt flood-prone Canadian jurisdictions like Manitoba,” Sandford said.

Whether Manitoba sinks or swims in this new environment will depend largely on the success of recent efforts to collectively craft a mitigation and adaptation water strategy for the entire basin. The alternative is “all of us falling pell-mell, every man for himself into a future we neither intended nor desire.”

Laura Rance is editor of the Manitoba Co-operator. She can be reached at 204-792-4382 or by email: laura@fbcpublishing.com.