Toronto Star

Extreme weather offers taste of what’s to come

- DONOVAN VINCENT FEATURE WRITER

Extreme and deadly heat in Europe, Asia and across Canada and the U.S.

Wildfires in California, British Columbia and here in Ontario, in Parry Sound and North Bay.

Tuesday night’s flood in Toronto that saw more than 70 millimetre­s of rain dumped downtown in two hours.

Climate experts say it’s all part of a trend the planet has been experienci­ng for the past 30 years, one we should expect to continue over the coming decades.

“It’s not new weather, just a more extreme (version) of the old weather. The weather seems more energized, more ramped up,” says David Phillips, a senior climatolog­ist with Environmen­t Canada.

The sizzling heat and heavy rains fit the pattern of global warming caused by increased greenhouse gases, climatolog­ists say. It’s a pattern that has had grave consequenc­es this year. Hundreds have died across the globe this summer, including in Quebec. There’s been flooding in Ireland, fires in Greece.

We’ve seen temperatur­es in Sweden’s northern region, inside the Arctic Circle, reach 32 C (nearly 90 F). Dubai, a hot city to begin with, saw scorching temperatur­es of 50 C in June.

California’s Death Valley topped that in July with temperatur­es that reached as high as 53 C.

That state, which saw its hottest July ever with an average temperatur­e of 27 C, has experience­d the worst wildfires in its history as a result.

Phillips noted that earlier this week, nine out of 10 Canadian provinces were in the grip of a heat wave — and the 10th had a heat warning.

It’s something you don’t often see in Canada, he says.

Worldwide, it’s the large area covered by the pattern of the heat this summer, plus the intensity of the heat and its duration — we’ve seen hot temperatur­es across Canada since May, Phillips notes — that all point to a warming pattern, he says.

The U.S. government’s National Oceanic and Atmospheri­c Administra­tion (NOAA) found that in the U.S., the average temperatur­e across the country in July was 25 C — 1.9 degrees above average.

That’s the 11th warmest average for the month in more than 100 years of the agency’s recorded temperatur­es.

Ahira Sanchez, a climatolog­ist with NOAA, points out that 2014 set a new record for global temperatur­es, 2015 broke that record, and 2016 broke the record again.

Last year was the third warmest year globally, according to a study headed by NOAA with input from more than 500 scientists in 65 countries. Published by the American Meteorolog­i- cal Society, the study found temperatur­es were .38 to .48 of a degree C above the 1981-2010 average.

The report also noted that last year’s levels of greenhouse gases, including methane, nitrous oxide and carbon dioxide, were at all-time highs.

The sea level had also risen to an all-time high — about 7.7 centimetre­s higher than in 1993, the study found.

The globe’s sea level has risen an average rate of 3.1 cm per decade, the study noted.

Environmen­t Canada’s Phillips says there’s plentiful and reliable data from rising sea levels and global temperatur­es over time, which make it easier to point to climate change.

However, flooding events such as Tuesday’s in Toronto, and the 97 millimetre­s that fell here in July 2013, are harder to connect to climate change because they are localized and don’t happen as often, Phillips points out.

But the general rule is that warmer air holds more moisture, therefore it stands to reason that persistent heat waves will result in heavier downpours like Tuesday’s, experts argue.

Tuesday’s flooding was a result of a localized “shower cell” that began around the Toronto- Vaughan border near Steeles Ave.

The cell intensifie­d significan­tly and moved slowly southward, with Toronto’s downtown core and the lake front taking the brunt of it, says Geoff Coulson, a meteorolog­ist with Environmen­t Canada.

The impact — flooded streets, flood damage to ceilings and basements in homes and businesses, and overburden­ed sewers — makes these downpours seem intense, but the infrastruc­ture and green space in Toronto isn’t adequate to keep up with the amount of rain we saw this week, Environmen­t Canada’s experts argue.

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