CANADA – OTTAWA — When it comes to extreme weather, 2018 has a throwdown message for last year’s show of hurricanes, forest fires and non-stop rainfall: hold my beer.
Predicting when and where extreme weather will hit can be difficult, if not downright impossible. But Tim Gray, executive director of Environmental Defence Canada, said Friday he has no doubt it will happen.
“I can say with certainty that we will have more wacky weather in 2018, and quite likely more than we did in 2017, as the world continues to warm,” Gray said in an interview.
For those who might have already blocked 2017 from memory, here’s a quick refresher: record heat and dry days in western Canada that fuelled B.C.’s most devastating forest fire season ever, while in Central Canada, it refused to stop raining and summer was missing in action.
The United States had one of its worst hurricane seasons ever, while parts of Europe suffered through deadly heat waves that led to forest fires and even the closing of summer ski hills in Italy and Austria for the first time in 90 years. In Australia, 2017 was the third-hottest year ever recorded.
The Swiss Reinsurance Company says insured losses from natural disasters in 2017 topped US$136 billion, twice the US$58 billion average of the last 10 years and the third highest level ever recorded.
Not everyone is convinced, however. Madhav Khandekar, a former Environment Canada ocean researcher, has written papers arguing against the notion that extreme weather events are becoming more frequent.
“It is just our perception about it that has been changing because of increased media attention,” said Khandekar, now retired and living in Markham, Ont.
Shawn Marshall, a geography professor at the University of Calgary and former Canada Research Chair in climate change, said weather events are very hard to predict and the research trying to improve that is still a work in progress. Even so, he said, scientists have recorded changes in climate due to the levels of carbon in the atmosphere, creating the conditions for a greater risk of extreme weather.
“Every year won’t be like 2017, however 2018 will still be one of the five hottest years ever recorded,” Marshall said.
Greenhouse gases like carbon and methane sit and gather in the earth’s atmosphere, where they trap heat as energy. The more energy in the atmosphere, the more the risk is for extreme weather. And the amount of carbon in the atmosphere grows each year.
Weather patterns and weather events have always been chaotic and always will be, said Marshall. But as the levels of greenhouse gases like carbon in the atmosphere grow, they trap heat. That heat energy in the atmosphere raises the risk of extreme weather, which is why climate change is linked to a higher risk of extremes.
‘Global warming’ doesn’t refer to a given temperature on a given day, he added, but rather the average temperature of the planet over a decade or more: “global warming is not just the weather.”
Scientists from the World Weather Attribution — an international partnership of researchers from the University of Oxford, Royal Netherlands Meteorological Institute, the University of Melbourne and the Red Cross Red Crescent Climate Centre — use historical records and climate modelling based on existing carbon levels in the atmosphere to look at weather events and whether they are linked to climate change.
The aptly named Lucifer heat wave , which hit parts of France, Italy and Croatia in August, was made 10 times more likely by climate change, the group concluded, and Australia’s hot 2017 60 times more likely. The rainfall that followed Hurricane Harvey in Houston was three times more likely, their research suggests.
And the cold snap? Climate change has meant such spells are actually less frequent and warmer than they have been in the past.