Extreme weather will always be with us, no matter what. The best way to cope with future extreme weather is to develop an “early warning system” with improved long-lead weather/climate forecasting capabilities. Such an early warning system can help minimize adverse impacts from future extreme weather events.
In the viewpoint article Extreme weather becoming norm (SP, June 28) Lidsay Olson, vice-president of the Insurance Bureau of Canada, provides a glimpse of weather extremes for various regions of Canada and warns Canadian to be prepared to live with such extremes over the next several decades.
Olson refers to the study on future weather extremes done by Gordon McBean, former assistant deputy minister of Environment Canada. When did Canada witness a climate free of extreme weather, is what Olson fails to explain to Canadians.
Extreme weather is an integral part of the Earth’s climate. Throughout the recorded history of the Earth’s climate, extreme weather events have always occurred somewhere, and are caused by large-scale atmosphere ocean flow patterns and their complex interaction with local/regional weather and climate features.
An examination of the 20th century climate of North America reveals that the decades of 1920s and 1930s, known as the Dust Bowl years, witnessed perhaps the most extreme climate over the Great American Plains and elsewhere. There were recurring droughts and heat waves on the Canadian/American Prairies.
The prairies also witnessed some extreme cold winters during the 1910s and 1920s – for example in 1907 and 1920.
We meteorologists still do not fully understand why the climate of North America was so anomalous during the 1920s and 1930s.
During the 1950s and 1960s most of Canada witnessed extreme cold winters, especially on the prairies where record breaking low temperatures (Edmonton at minus 45C and below in the 1960s) were registered. In Ontario and Quebec, cold and snowy winters was a norm during the 1960s and early 1970s.
Parts of the Canadian Atlantic witnessed long winters with lots of snow. Spring ice jam on the St. John’s River was a common occurrence during the 1960s and 1970s.
The recent decades of the 1980s and 1990s have witnessed a warmer climate across most of North America and worldwide.
Several hot spells of varying durations (from few days to a week or more) have been recorded in North America, Europe and elsewhere. The year 1998 has been adjudged the “hottest year” in a 150-year long temperature record, according to the Intergovernmental Panel on Climate Change, the UN Body of climate scientists and environmentalists.
Will the Earth’s climate become significantly warmer in future? There is no definite answer so far. The best value for climate sensitivity (increase in the Earth’s mean temperature in future for a doubling of the atmospheric CO2 concentration) is now estimated to be just about 1C or so.
Would such a modest increase in future lead to increased severe extreme weather events, as Olson claims?
Would future extreme weather be any different from what Canadians have witnessed in the past?
Extreme weather will always be with us, no matter what. The best way to cope with future extreme weather is to develop an “early warning system” with improved long-lead weather/climate forecasting capabilities. Such an early warning system can help minimize adverse impacts from future extreme weather events.
Canadians from coast-to-coast should be able to live and cope with future weather extremes with adequate precaution and need not be psyched into accepting increased insurance in future, as Olson’s article seems to suggest.
Khandekar is a retired Environment Canada scientist with more than 50 years of experience in weather and climate science, and an expert reviewer of the IPCC 2007 Climate Change Assessment.