By Dave Flaherty/The Oshawa Express
If you get the feeling of being hotter as you drive into the city from Durham’s more rural areas, it’s not your mind playing tricks on you.
In a recently released report from Durham Region, it details how the region plans to address the phenomenon known as urban heat islands, a term used to describe the temperature difference between urban and rural areas and can refer to surface temperatures, air temperatures or a combination of both.
According to the region’s report, air temperature differences in large North American cities can be one to three degrees warmer than rural areas on a sunny day, and up to 12 degrees higher at night.
These heat islands are generally created by land use practices and most usually occur alongside urban growth and development.
Specific factors contribute to these sweltering heat pockets.
A lack of vegetation, dark-colored materials used in sidewalks and parking lots, taller buildings, which absorb more solar energy, and heat waste from machines such as air conditioners and industrial equipment can all lead to the creation of heat islands.
Weather conditions and geography also play a part, with temperatures more moderate in areas located closer to large bodies of water.
The report notes the urban cores of Oshawa, Whitby, Pickering, and Ajax are hotter than the more rural and forested areas of north and east Durham and are most susceptible to developing urban heat islands.
Within the City of Oshawa, residential and commercials areas north and south of Highway 401, along with the industrial park in the southwest corner of the city near Lake Ontario show the highest land surface temperatures.
With Durham’s population projected to double in the next two decades, it is suggested that this phenomenon will only increase as further development will replace more vegetated landscapes with roads, pavement, and buildings.
With the recent extreme heat warning aside and the sweltering temperatures that come with it, these urban heat islands also pose risks to human health, with an aging demographic and higher than normal rates of asthma and lung disease. It is believed increased health risks are likely as well in the years ahead.
But the consequences run far deeper.
Electricity costs and demands are higher in urban areas, while also increasing the chances of potential blackouts, which can have significant impacts on the local economy.
Secondly, increased energy use leads to higher emissions of greenhouse gases and air pollutants, while stormwater running over hotter surfaces can flow into rivers and creeks, raising the temperature and affecting aquatic life.
Residents and employees who live or work in urban buildings with inadequate cooling or ventilation can suffer in terms of overall quality of life or work performance.
In a 2015 Health Canada Study, several measures were advised to reduce the urban island effect.
These include increased vegetation in urban areas, “cool” roofs that include gardens and trees, and better heat alert planning and protection.
Increasing urban forests is a step taken by the City of Kingston to battle urban heat islands. It is estimated the 28,000 trees that make up the city’s urban forest have provided $1.87 billion in benefits including reduced energy use, better air quality, and carbon storage.
In 2016, Durham regional council adopted a climate change adaptation plan titled ‘Towards Resilience.’
In preparing the plan, the region collaborated with more than 60 experts.
Addressing urban heat islands is one of the plan’s priority initiatives.
Brian Kelly, manager of sustainability for Durham Region, says it will not be a quick fix.
“We are not going to solve the problem overnight. It’s taken a long time for us to get here and it will take a long time to resolve the problem,” Kelly says.
To him, one of the first steps is empowering local government to enact change.
“We are working on moving ahead with a program next year to allow the local municipalities to work with landlords to regulate maximum temperature in apartment buildings,” he says. “The City of Toronto is moving forward quite aggressively with their old apartments, and they certainly have more older apartment buildings than us. We are hoping to piggyback on their programs.”
While retrofitting these buildings would lead to more energy efficiency, more immediate steps can be taken.
“You can’t snap your fingers and retrofit old apartment buildings. But could common rooms be converted to a cooling station to get people without air conditioners down for some relief?” Kelly explains.
Many buildings do not allow residents to have air conditioning units, but also have windows that are not easily opened due to past safety concerns.
However, this has created a separate issue of residents being unable to find relief through cooler nighttime air.
“In a lot of old apartments, the windows are jerry-rigged so they can’t open too far. We need to retrofit windows and put in tougher screens,” he says.
Kelly also wants to work with developers to construct housing better adapted for changing climates.
“Why do we typically default to black shingles? [which absorb more heat] Why can’t we look at lighter coloured shingles. Basically, we are in this time lag where we are constructing buildings as if we are still living in cold climate.”
And while urban forests have proved successful for other municipalities, Kelly believes it goes far beyond simply planting thousands of seeds.
“We have to get the tree species right. The trees we would have planted 20 to 30 years ago are probably not the species we should be planting now.”