Sydney, N.S., stands out for temperatures strongly linked to climate change in recent months: data

It's felt like an unusually hot summer to Mayor Amanda McDougall-Merrill of the Cape Breton Regional Municipality.

The heat is "not something that we've had to deal with as frequently as we had this summer," she said. "It's been really rough."

With temperatures as high as 33 C in recent months, the CBRM has had to respond to scorching temperatures by doing things like adjusting the times its employees work outdoors and spreading the word of free public spaces where residents can escape the heat, McDougall-Merrill said.

According to new data from U.S.-based climate science organization Climate Central, these conditions in Sydney, N.S., stand out from other places.

Out of 110 Canadian cities studied, Sydney had the third-highest number of days in June and July where temperatures had "very strong" links to climate change.

The organization's Climate Shift Index estimates how much more likely a location is to experience different temperatures due to human-caused climate change.

In June and July, Sydney had 13 days at a Climate Shift Index value of four or higher. According to Climate Central, this indicates extreme or exceptional climate change events.

During that time, Sydney also had the second-most unusually warm daily temperatures out of the Canadian cities studied, averaging 2.1 degrees higher than the baseline from 1991 to 2020.

And there will be more days in the future of uncomfortably warm temperatures, along with longer seasons with the potential to hit them, said Andrew Pershing, a climate scientist and vice-president for science at Climate Central.

"These are the conditions you should expect to have going forward."

McDougall-Merrill said the CBRM has had a large learning curve in recent years when it comes to being prepared for disasters and the effects of climate change.

Since post-tropical storm Fiona hit in 2022, the municipality has secured more than $1 million in funding to help upgrade its emergency management services. 

There is now a dedicated command centre, McDougall-Merrill said, and comfort centres throughout the municipality that have been upgraded with things like large generators. She added these centres could potentially be deployed during extreme heat.

Another separate and new study from Climate Central also found that climate change has led to more warm nights in Nova Scotia and the Maritimes. 

The study examined how many times nighttime temperatures over the last decade exceeded temperature thresholds above which some experts say there can be negative health impacts. It also estimated how many nights those thresholds would have been exceeded without the effects of climate change.

"Nighttime temperatures are warming faster than daytime temperatures all over the world," Pershing said.

In Nova Scotia, the study estimated climate change has added about three nights each year with a temperature above 20 C — the second-highest increase among the provinces and territories.

This was behind Prince Edward Island, where the study estimated there have been nine additional nights each year on average above that temperature threshold.

Pershing said the ocean is one reason why Maritime provinces are seeing these effects, with humidity playing a large part in setting nighttime temperatures.

"A warmer atmosphere [from climate change] can hold more water vapour, so it's going to be more moist and … trap more of that heat" from the day, he said.

When nights are warm, people don't have as much ability to cool down from the day, said Dalhousie University professor Daniel Rainham, who studies the effects of environments on health.

That can then affect peoples' ability to sleep, leading to negative health effects.

"It can also increase [the body's] stress response," he said. "This can lead to all kinds of things like heart disease and even cancer in the longer run."

Rainham added that infants and older adults are particularly vulnerable to the dangers from heat. They can include dehydration and heat stroke, both of which can be life-threatening. 

"The effect of heat can creep up on you without you knowing."