LONGER, HOTTER SUMMERS
Experts say heat is our new norm
The record-breaking weather Calgary and much of Alberta has seen since the start of summer is likely to continue through July and August, according to Environment and Climate Change Canada (ECCC).
But a University of Calgary climatologist says it's the effects of climate change over the next decade we really need to be concerned about.
As Alberta enters its second significant heat wave in recent weeks, temperatures in the high 20s C and low 30s C will continue to scorch the Calgary region for the forecastable future.
More than 80 per cent of the province, including Calgary, was under a heat warning Wednesday, with daytime temperatures ranging between 29 C and 33 C in the city. Temperatures are expected to cool by Saturday but come back up on Sunday to near or above 30 C.
This year was the second-hottest June on record, behind 1961, with the hottest day, June 29, coming in at 36.3 C, only 0.2 C off the highest temperature ever recorded in Calgary.
“On average, we typically only see five days above 30 C in the Calgary area. We've had 12 so far this year, and we have four more in the forecast for this week,” said Kyle Fougere, ECCC meteorologist.
“That forecast goes on till Tuesday but, next week, there's not really a strong signal for cooling. ... With this ridge of high pressure over the province, we're not forecasting any record-high temperatures for an individual day, but it's going to be consistently above normal for this week and likely into next week.”
Fougere noted Calgary has nearly reached a normal amount of precipitation, with 61 millimetres of rain falling since July 1. The average for the entire month is 65 millimetres.
The ridge of high pressure the city is under creates a heat dome, much like what was seen at the end of June, and though temperatures in Calgary aren't expected to climb past the low 30s this time around, we can expect much of the same weather until fall.
ECCC forecasts a warmer and drier July and August than normal, which Fougere said is going to become more common “in our changing climate.”
University of Calgary climatologist Shawn Marshall said such heat waves in Alberta were to be expected as a result of climate change, but not so soon.
“This is kind of what people are forecasting with climate change, but it feels ahead of schedule and more intense than anyone would have forecast for this summer or even for the next decade,” he said.
As air from the southern “desert belt” of the U.S. makes its way into Western Canada, Marshall said we'll continue to see more energy in the atmosphere producing heat and altering air circulation.
“This one is just stronger than anything we've seen before,” he said. “And it feeds off itself a bit because once you've got the stable, hot, high pressure air, things dry up and then you don't have moisture, so you don't have that evaporation that cools things off.”
Marshall said with this heat wave coming so soon after the last, it's important to have discussions about how Alberta will be affected by climate change.
“There's a lot of impacts beyond hurricanes and sea level rise and things that other parts of the world are feeling pretty acutely. In Alberta, this comes to us as dry heat like this, because it really is this desert-like conditions that are moving in and that's affecting agriculture, affecting water resources,” he said.
“Going forward with climate change, as we lose the glaciers from the Rockies, that's going to exacerbate this kind of water resource stresses in these hot, dry summers. ... That affects water allocations in the irrigation districts and there's a real challenge to the viability of some agriculture in the southern Prairies.”
As wildfires in B.C. continue to rage, with more than 300 fires across the province, hazy and smoky conditions wafted into Alberta on Wednesday, with the air quality sitting at a “4” out of 10 in the morning across Calgary, moving to a “5” in the evening and back down to a “4” by Thursday.
The effects of wildfires will also continue to be felt in Alberta and Marshall said the fire season will likely start sooner each year.
“It's going to get worse before it gets better in terms of fire,” Marshall said. “Firefighters tend to talk about 30/30 conditions; temperatures above 30 and relative humidity below 30. And that's exactly what we get around here. ... It's a very solid prediction under any climate change scenario I've ever seen for where we live.
“It's going to have pretty severe forest impacts and evacuations and costs, air quality issues and very direct fire hazards if you're living and playing in the foothills.”
Though Marshall said it does sound all very doom and gloom, taking the politics out of the equation is key to learning how to cope with climate change in Alberta.
“Not everything is negative with climate change but these kind of intense heat waves and fires and water stress is something we're going to need to learn to live with in coming decades.”