New heat wave alert system designed for Quebec in wake of climate change
MONTREAL -- Experts say extreme heat waves will likely become more frequent occurrences in Quebec due to climate change.
As a result, they have developed a new alert system to help public health officials warn Quebecers of impending weather conditions to avoid deaths and hospitalizations.
The alert was created by researchers at the Institut national de la recherche scientifique (INRS), in collaboration with the Institut national de santé publique du Québec (INSPQ).
Weather alerts are typically triggered when a certain heat threshold is expected to be reached and continue on for several days.
This allows health authorities to notify the population, as well as organize hospital beds and make decisions on whether to extend the opening hours of swimming pools, libraries and air-conditioned shopping centres.
According to current climate projections, heat waves will continue to extend beyond the summer season in the coming years and decades.
The management of heat waves will become complex, particularly because of their increased frequency and intensity, notes the INRS.
In the current alert system, temperature thresholds are the same all year round, regardless of the month, points out Fateh Chebana, a professor of statistical hydrology with the INRS involved in designing the original alert system.
He explains that 32 degrees Celcius in April doesn't have the same effect on the body as it does in July.
This is taken into account in the new alert model: in April, for example, the threshold is lower than in July: 23 degrees Celcius versus 32 degrees Celcius.
These new temperature thresholds were determined based on data from heat-related hospitalizations and deaths.
"We want to be as realistic as possible. A model is a simplification of reality, but we don't want to oversimplify or stay glued to reality," he said.
While a temperature of 23 degrees Celcius in April might make most people happy, it can be harmful to vulnerable populations if it lasts several days.
"This adaptive system has the potential to prevent heat-related mortality outside of typical heat wave periods," he said.
In addition, as heat waves have started occurring both earlier and later in the year, researchers have added two more months to the alert system: April and October; the current system was active from May 15 to Sept. 30.
Last April, the mercury often exceeded 24 degrees Celcius in Montreal, though the average is usually 12 degrees Celcius.
A heat wave was recorded in May in southern Quebec, with temperatures over 30 degrees Celcius on three consecutive days.
The new alert system model also has the advantage of being designed specifically for Quebec.
It was first developed for the City of Montreal, "a relatively small, homogeneous area with a lot of data," but will be adapted to other Quebec regions. Chebana notes it could also be modified to suit other Canadian provinces, as well as different countries.
Environment Canada's heat alert system is "generic," according to Chebana, as it is designed for all kinds of uses and is not "health-specific."
The results of the researchers' work will be published in the scientific journal, BMC Public Health.
Public health officials say they plan to analyze ways to integrate the results of this research into the province's health monitoring system.
-- This report by The Canadian Press was first published in French on July 21, 2021.