Peter Janzen/cc0.photo

The record-shattering wave of heat and humidity blanketing parts of Quebec, Ontario, and the United States, affecting Canada Day celebrations in the nation’s capital and World Cup matches in both countries, “would have been virtually impossible in a climate without fossil fuel use,” Oxford University-based World Weather Attribution (WWA) has concluded.

The news landed just hours after Prime Minister Mark Carney announced additional federal backing for four liquefied natural gas (LNG) terminals in British Columbia and overwhelming taxpayer support for a new million-barrel-per-day pipeline from Alberta to the B.C. coast. The pipeline is meant to double daily oil sands production over the next 10 to 15 years.

“The heatwave is being driven by a strong ‘heat dome’ high-pressure system that is bringing hot and humid conditions from the south,” driving temperatures above 38°C in the southern parts of both provinces as well as the central and eastern U.S., WWA states [pdf]. “While this is a typical weather pattern, it now leads to higher temperatures as a result of human-caused warming.”

If not for 1.4°C warming since pre-industrial times, the release adds, the temperature and humidity extremes based on the Wet Bulb Globe Temperatures (WBGT) heat stress measure “would have been so rare they would have been virtually impossible (at most, not expected to occur even once in many thousands of years).”

When national holidays in both countries are disrupted, and World Cup matches “are played in conditions that are unsafe for players and fans, it shouldn’t take another scientific study to wake people up,” declared Prof. Friederike Otto, professor of climate science at the Centre for Environmental Policy, Imperial College London. “Climate change is here, it’s already impacting the things we enjoy in our everyday lives, and it will continue to get worse the longer we drag out the inevitable transition to net-zero emissions.”

With messaging that focused much more on U.S. Independence Day July 4 than Canada Day July 1, WWA identified upcoming World Cup pairings in Toronto, Miami, and Philadelphia that “are all likely to be played in extreme heat and humidity,” with a July 4 match between France and Paraguay expected to exceed safe levels to play.

Ottawa has already seen the humidex, a combined measure of heat and humidity, reach 46°C on Canada Day. Then the skies opened, bringing a record 118 millimetres of pounding rain that flooded more than 1,900 basements, damaged foundations in at least one riverside neighbourhood, flooded roads, highways, and underpasses, downed trees, cut power for 29,000 households, and cancelled Canada Day celebrations on Parliament Hill.

Instead, electronic billboards on the Hill and at LeBreton Park to the west urged would-be party-goers to “seek shelter”.

The WWA report addresses heat and humidity, but not flooding.

The 12-page scientific report [pdf] cites heatwaves as “the deadliest type of extreme weather, with hundreds of thousands of people dying from heat-related causes each year.” The urban heat island effect makes extreme heat particularly dangerous in cities, WWA says, with historically redlined districts up to 7°C hotter than non-redlined areas.

And this heat dome is delivering more than just record-breaking extremes, the scientific report adds.

“The terms record-shattering and record-smashing have recently been introduced in the scientific literature to distinguish events that exceed previous records by unusually large margins. Research shows that the likelihood of shattering records is proportional to the rate of warming, meaning that the very fast increase in greenhouse gas emissions in recent years has made such events much more likely.”

While air conditioning “is largely protective of the general population in the U.S. and Canada, it highlights those without access to air conditioning due to economic constraints, outdoor job requirements, or limited mobility as most vulnerable to health impacts,” WWA states. “Further, the potential for high energy consumption as millions of people turn on their home air conditioners during the holiday weekend will stretch electricity grids, creating the possibility of power outages which would expose a larger part of the population to oppressive heat and humidity.”

On Friday, Clean Energy Canada and partners launched a Heat Pump Summer challenge to spark local conversations about a more efficient option for summer cooling, as well as winter heating. “91% of Canadian heat pump owners say they’d recommend one to a friend or neighbour,” the challenge page states. “So this summer, we’re turning that enthusiasm into action.”

Trending Stories

Leave a Reply

Get the latest climate news and analysis, direct to your inbox.

Related Articles

Follow Us