'Heat island' effect creating hotter conditions in Halifax, but there are solutions

Halifax's clogged arteries are doing more than steaming rush-hour commutersthey're also crankingup the temperature in the urban core, according to a researcher at Dalhousie University.

Halifax is amonga number of Canadian cities experiencing hotter weather than its outlying areas due to what's called the"heat island"effect,saidProf. ChristineMacy.

The effect occurs when heat is absorbed by buildings with dark surfaces and asphalt or concrete roadways, effectively trapping heat and warming these surfaces.

Cities also tend to generate their own heat with the frequent use of vehicles and air conditioning units, exacerbating the effect.The severitydepends largely on a city's layout and the amount of vegetation in its neighbourhoods. Macy, who teaches at Dalhousie's architecture school, saida dependency on vehicles is making the problem worse.

She said Halifax has beenprioritizingwider paved roads andnew parking lots over trees and vegetation, intensifying the heat islandeffect.

"They have been doing that since the 1950s, increasing the size of roads," she said."When you replace greenscape with hardscape, it's absolutely making things worse."

A reduction in paved areas

The heat island effectcan make a city up to five degrees warmerthan surrounding areas, said Rob Leblanc, a landscape architect at Fathom Studio, an architecture firm in Dartmouth.

Although the effect is only getting worse as climate change intensifies, according tothe Climate Atlas of Canada,there are ways to mitigate the heat the city is generating.

"I think some of the biggest impacts is reducing the amount of parking lots in urban areas or reducing the amount of streets," said Leblanc.

Leblanc said there are stronger measures that could be taken by the Halifax Regional Municipalityand its residents.

"Getting public transit to work better so that we don't need as many streets, getting active transportation, getting people on bikes," he said.

Shannon Fernandes, the manager of thecity's climate adaptation division,said the city has been working on ways to curb the heat islandeffect since the spring.

"We are seeing hotter summers and heat waves and more extreme heat temperatures and we are working on a number of initiatives to help address the heat island effect and extreme heat in our urban cores and across the municipality," said Fernandes.

Municipal initiatives

Some of these initiatives include keeping track of areas that are being hit particularly hard by theeffect, the environmental factors involved and who is being most affected. This will also provide insightinto what will decrease residents'vulnerability to heat, includingincreased vegetation and more cooling centres.

"When we look at a map of urban heat islands, we can see the correlation between heat and vulnerable population," said Fernandes. "We know that older adults, we know that adults and children with pre-existing conditions suffer more from urban heat and extreme heat."

But Macy said identifying problem areas and who is most impacted in the city isn't enough.

Macy asserts the city should heed the interests of younger residents and take long-term action to make the citymore livable, rather than just more convenient. This includes creating greener spaces and discontinuing projects that involve increased paved areas.

"I think people are very interested in trying to make the city more livable. And there's wonderful, wonderful features and characteristics in Halifax," said Macy.

"But you can't be chasing modernity from 40 years ago. You have to be looking at what younger people are expecting now."