Record warming: How should Canada, its cities and citizens adapt?

Trees, green roofs, heat sensors and other climate change action and adaptation
Trees, green roofs, heat sensors and other climate change action and adaptation strategies are crucial for cities, where extreme heat is magnified. (Julide Cakiroglu/Western Communications)
In January 2024, the European Union’s Copernicus Climate Change Service (C3S) announced 2023 as the hottest year on record since 1850 . On May 8, the C3S reported the record-breaking temperature streak had extended, with the world experiencing its hottest April on record.

Gordon McBean, professor emeritus in Western’s department of geography and environment, has studied global warming and the effects of climate change for the past five decades, making contributions recognized by the Order of Ontario, Order of Canada and the 2007 Nobel Peace Prize, which he received as part of the Intergovernmental Panel on Climate Change team.

Gordon McBean (Christopher Kindratsky/Western Communications)

He says these latest reports raise a heightened call for action from all Canadians.

"Canada, with its large land mass, much of which is located at higher northern latitudes, is warming twice as fast as the global average - and the Canadian Arctic, three to four times faster," he said. "The reality of these enhanced rates of warming should be enough of a reason to motivate governments at all levels - and all citizens - to work together to do something. We need more than just policies. We need plans, going into action."

Adding to the urgency is the fact that heatwaves brought on by the extreme heat caused by climate change will be magnified in Canadian cities. That’s because of the urban heat island (UHI) effect, a term used to describe the relative warmth of urban areas compared to their rural surroundings.

James Voogt (Christopher Kindratsky/Western Communications)

Urban climatology expert James Voogt, a professor in Western’s department of geography and environment who studies UHIs as part of his research, says that’s a significant concern.

"In the future, this increased external heating will be super-imposed on people already experiencing local heat, taking us beyond fixed thresholds where health risks increase for older adults, children and vulnerable populations," he said.

McBean, who’s held many roles in his career, including serving as assistant deputy minister of Environment Canada (1994 to 2000) and as president of the International Council for Science (2014-2018), knows addressing these issues is not an easy fix.

But it’s his most treasured role that keeps him optimistic in the fight to protect our warming planet.

"I’m a grandpa. For my kids, their kids and for all kids across the world, we need to do things in a way that really makes a difference." - Gordon McBean, professor emeritus, department of geography and environment

Moving forward: An integrated approach to mitigation and adaptation

McBean says Canada must first keep its commitments to the Paris Climate Agreement, with transparency about efforts taken to reduce greenhouse gas emissions and action on climate change adaptation.

"This is a global problem that we’ve all contributed to and one that we need to collectively solve," he said. "We also have to recognize that when CO2 is put into the atmosphere, it stays there about a century. So, it is not what you put in last month, last year or the last decade, it’s what we’ve collectively put in for a century. Even if we were to stop greenhouse gas emissions globally tomorrow, we would still warm for at least three, four or five decades."

That’s why as lead author of the paper Building Climate Resilient Communities: Living Within the Earth’s Carrying Capacity , he says a Canadian adaptation strategy is crucial if we are to reduce our vulnerability to the impacts of climate change - severe weather, extreme heat, floods and tornados.

Adapting successfully will take an integrated approach across all sectors, jurisdictions and levels of governance - a challenge McBean studied as senior author of a 2018 study exploring the governance of climate change adaptation in Canada.

"For Canada to adapt and thrive in the face of climate change it will take the shared responsibility of all Canadians to do their part," he said, noting an engaged public, educated on the science behind global warming, helps ensure key policy instruments will be funded and implemented.

Helping cities better beat the heat

Voogt echoes McBean’s call for an integrated approach.

As an esteemed urban climatologist, he’s part of a group of scientists providing a growing body of literature showing the crucial role urban areas play in mitigating and adapting to impacts of climate change.

"Cities are important sites to think about mitigation and adaptation, but need resources, contributions and incentives from different sources, including multiple levels of government," he said.

Voogt specializes in the measurement and modelling of urban surface temperatures and has made significant contributions to the understanding of the three-dimensional surface temperature, using sensors to collect data. This will help build more powerful computer models to test the effectiveness of different mitigation and adaptation strategies.

Voogt, who earned the 2022 Luke Howard Award for Outstanding Contributions to the Field of Urban Climatology, calls cities a "harbinger of climate change."

"We already know some things that will happen with large scale warming, because we’ve seen what happens when cities get warmer," he said.

The concrete, asphalt and other construction materials used to pave city roads and construct buildings readily absorb and trap sunlight, raising local temperatures to a higher degree.

Voogt focuses on these surface areas to help understand how cities are affected by climate change and to inform design strategies that reduce those temperatures.

"You can tell what the atmosphere is doing by studying these surfaces," Voogt said. "Conditions in the lowest part of the atmosphere are influenced by characteristics of the surface. Because surface areas are so different in cities, they’re able to create their own climate."

While remote satellite sensors can measure surface temperatures, Voogt says buildings pose a problem by blocking the view, preventing the sensors from actually "seeing" all the surfaces.

His research instead uses tiny heat sensors that can be hung on building walls, rooftops and, sometimes, a roaming research truck. They capture the temperature variations of buildings, pavements and roads - which all’absorb and reflect sunlight in different ways - to get a more accurate picture.

The data his team collects can help build more powerful computer models for accurate weather forecasting and to test the effectiveness of some climate mitigation and adaptation strategies. Those strategies could include the use of white roofs to reflect the sun or green roofs to promote cooling and the use of trees and vegetation to provide shade and transpiration.

"It’s not that we don’t know how much shade a tree gives, or what the temperature difference is," Voogt said. "It’s determining the average across the whole block which is a bit harder to do."

Testing trees in the Forest City

In 2017, Voogt and his team conducted a survey in London, Ont., measuring daytime temperatures at ground level on two streets. One street was dense with urban trees, while the other had very few. Data collected from the centre of the road, in what’s known as a "heat canyon" between buildings, showed the street with dense tree cover was cooler. It also confirmed trees reflect and transform radiative heat before it reaches street level.

While trees are a pretty powerful tool for mitigation in London, Ont. Voogt notes "if you’re in a desert city, you might not want trees, given it would cost a lot of money in water to keep them alive."

What’s key, Voogt said, is "getting cities to think about their local climate." In Canada this means considering the different seasons. In hot, humid climates by the ocean, it’s ensuring daytime sea breezes can reach and cool the city.

"If you build a bunch of buildings along the shoreline, those pathways of cool air can’t flow through," Voogt said. "It’s important to consider what natural, local climate cities are embedded in and what sources might be climate problems or climate resources."

Addressing heat vulnerability

Responses to urban heat must also address the inequities experienced by people who can’t afford or don’t have access to air conditioning, shade or shelter.

"It’s not just the physical parameters of where it’s hot, but who is exposed to that heat," Voogt said. "We know from local work that people experiencing homelessness are exposed to heat more and experiencing greater impacts because they are showing up at emergency rooms atá a much greater rate than the general population. City-run cooling centres are an important resource, but they’re not a cure for heat."

Voogt believes positive changes can be made - and has seen some already underway to lessen the impacts of climate change on communities and cities.

"At the urban level, we’ve seen a big ramp-up in the appreciation of climate change, with a lot of cities creating emergency plans and building in the expertise," he said.

"Sometimes, it just takes a long time to get things approved due to the aspects of urban planning and jurisdictions from multi-level governments. But, in the end, climate doesn’t care about that, it’s just responding to the realities of our rising temperatures."

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