Hotter University of Winnipeg geography professor predicts weeks of plus 30 C summer days
Hurricane Sandy and the devastating Midwest drought have convinced many Americans that climate change is real, and Prairie residents may soon have reason to feel likewise, says a University of Winnipeg geography professor.
“We are in climate change central in this part of North America,” Danny Blair said in a recent presentation to Ag Days, Manitoba’s largest annual ag event.
Blair, who is the university associate dean of science, pointed to predictions that average Prairie temperatures could rise by 2 C, on top of the 2 C to 4 C increase that’s occurred in the last 40 years.
“If you move the mean temperature of the summer warmer by a couple of degrees, that doesn’t just mean everything is going to be 2 C warmer,” he said. “It changes the statistical distribution of extreme events… and the probability of having really extreme temperatures goes up.”
Projections are that Winnipeg could have as many as 70 days with average temperatures of 30 C by century’s end, he said.
“Right now we have 13 days,” said Blair. “It is, shall I say it, Nebraska-type weather, or even Texas kind of weather from those extremes.”
Echoing David Chilton, the financial guru who brought a ‘don’t consume what you can’t afford’ message to Ag Days, Blair said people need to think about what their consumption is doing to the planet, too.
“We need to think about consumption from an environmental point of view, too,” he said.
Blair said he understands why many are skeptical of climate change, and cited an older farmer he had talked to that morning.
“He’d said to me, ‘Haven’t we always had climate change?’”
Blair’s response was that this is different.
“Yes, climate has always changed and there are natural processes that have changed the climate,” he said. “But we are convinced within the scientific community that the warming we’re seeing now and that we’re going to see for decades to come is caused by us.”
In the 1700s, before the Industrial Revolution began, carbon dioxide levels in the atmosphere were 280 parts per million. Today, it’s 394. Gesturing to a teen in the front row, he said, “By the time this young man is an old man, it may be 500, 600, 700 parts per million. That’s where we’re going — unless we clean up our act.”
That’s going to be tough as a third of CO2 in the air will still be there a century from now, and nearly a fifth of it will linger for 1,000 years.
Carbon dioxide from burning fossil fuel, has increased “radiative forcing,” the difference the amount of heat the planet receives versus what is radiated into space. Scientists estimate the increase in greenhouse gases is generating the heat equivalent of a 1.6-watt light bulb per square metre.
“What we’ve done to the atmosphere, by changing the composition of the atmosphere, is essentially hang a Christmas tree bulb to burn over every square metre of the earth’s surface continually,” he said.
“Does it seem like very much? No it doesn’t. But it’s there. And it’s significant enough to change the planet.”
Powerpoint slides of Blair’s Ag Days presentation are online at: http://dannyblair.uwinnipeg.ca/presentations/blair-mbagdays-15jan2013.pdf.