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Doing something about the weather

The summer of 2006 was the second hottest on record; this winter is shaping up to be the mildest

From ice storms to frost protection to field flooding, agriculture is all about dreaming of finding some way to control the weather. According to climatologist Henry Hengeveld, society already has – through increased greenhouse gases.

The summer of 2006 was the second hottest on record;
this winter is shaping up to be the mildest

The fact that the 1990s was the warmest decade of the last century, and the beginning of the 21st century has been even hotter due in large part to human intervention, disputes the old saying that everyone talks about the weather but no one does anything about it, retired weatherman Henry Hengeveld says.

He believes the greenhouse effect caused by human industrial activity has changed the earth’s climate and has given us even more  “weather” to talk about. “Climate is what you expect, weather is what you talk about,” he says, quoting Environment Canada’s senior climatologist and best-known weatherman Dave Phillips.

Climate is weather over the long haul and is what is expected to happen. So when there is a rapid change in climate, something is to blame. For instance, the overall temperature in Antarctica has risen from –6ÞC to 0ÞC from 14,000 BC and is expected to rise to plus 6ÞC in the next 100 years, says Hengeveld. The only possible answer is man-made changes to the environment.       

“There was increased volcanic activity in the ’90s and that should have caused cooling as the dust reflects the sunlight. But the temperature increased due to heat being trapped by greenhouse gases. We are doing something about the weather,” he says.
 
Good news with a dark side
The former Meteorological Services of Canada weatherman, now with Agriculture and Agri-Food Canada, predicts that southern Ontario will be drier and warmer over the next 50 years, which should be good news to most farmers as that’s better weather for growing most crops. But he warns there is a dark side – droughts, more frequent severe weather, and periods of intense rainfall.

The summer of 2006 was the second hottest ever recorded at the Hamilton Weather Office of Environment Canada, just 0.1ÞC degrees behind the mark set in 1998. Summers in declining order from 2004 to 2001 have been hot, but not quite as hot as in 1998, which indicates a trend toward hotter and drier weather, he says.

“We are doing something about the weather,” Hengeveld says, pointing to an unprecedented number of hurricanes during 2005 in the Caribbean. Locally, Peterborough in central Ontario has been hit with two one-in-a-hundred-year rainstorms in the past three years, and the month of January in 2006 was by far the warmest ever, he says.

In mid-March 2006, Environment Canada reported that Canada had its warmest winter since national record keeping began in 1948. The average temperature was 3.9ÞC degrees above normal, eclipsing by almost one degree the previous mild winter of 1986-87 when the average temperature was 3ÞC degrees above normal. So far this season, the 2006-2007 winter is shaping up to beat last winter’s warm temperatures. Eight of the 10 warmest winters have occurred since 1981.

Dr. Barry Smit and Dr. Susan Beliveau from the University of Guelph, which now runs the research station in Niagara, believe agriculture will have to adapt to climate change.

“Water supply will be key to planning agricultural practices,” Dr. Smit says. Decision makers should be engaged, relevant hazards and management practices identified, and climate risks managed, he adds.

Wind machine update  
Dr. Beliveau recently looked at the risks of climate variability and change for grape growers in the Okanagan Valley in British Columbia. Growers there are more at risk of killer cold –23ÞC winter temperatures than in Ontario, she says, and have to make a bottom line decision weather to risk planting cold susceptible varieties like Merlot.

In Ontario, grape growers who have put up $30,000 wind machines have to ask themselves following the 2005-2006 winter and the current 2006-2007 winter if the investment was worth it. Last winter was an unusually mild winter, as is this one, after two severely cold winters and the machines that pull down warmer air to mix with cold air at ground level were only used on two nights – Dec. 12, 2006, and Feb. 6, 2006 – by most growers who have them, says agricultural engineer Hugh Fraser. As of mid-January 2007, the machines had not been used at all for the current winter season.

Fraser is with the Ontario Ministry of Agriculture,Food and Rural Affairs and involved in a three-year study to measure the effectiveness of the machines.

The 2005 data showed on average a 62 per cent survival rate for seven vinifera grape varieties using wind machines compared to 35 per cent survival without the machines. The survival rate of three high-risk vinifera varieties – Merlot, Sauvignon Blanc, Shiraz – was 30 per cent using the machines and 24 per cent without, indicating that when the temperature falls to –23ÞC, as it did one night in January 2005, there will be damage in spite of the machines mixing the air.