It was hot in 2025 and the heat is forecast to continue this summer. Urban centres feel the high temperatures more than outlying areas due to the “urban heat island” effect.
How effectively they deal with the increased number of extreme heat events is critical for the comfort of their inhabitants.
“We cannot air condition our way out of the heat crisis, which would drive greenhouse gas emissions higher and raise costs,” said Inger Andersen, executive director of UNEP. “Passive, energy efficient and nature-based solutions can help meet our growing cooling needs and keep people, food chains and economies safe from heat as we pursue global climate goals.”
Even so, the UNEP’s Global Cooling Watch 2025 projects, “cooling demand could more than triple by 2050 under business as usual, driven by increases in population and wealth, more extreme heat events and low-income households increasingly gaining access to more polluting and inefficient cooling.”
Andersen says that, “faced with the increasing number and intensification of deadly heat waves, access to cooling must be considered an essential infrastructure on par with water, energy and sanitation.”
The UNEP recommends several passive strategies that have been mentioned before, such as “tree canopies, urban forests, green roofs and parks, water bodies, or blue infrastructures such as lakes, rivers, ponds, canals and reservoirs.”
To improve the uptake of these suggestions in large urban centres, some see government policies as an answer.
André Picard, health columnist at the Globe & Mail, writes while minimum mandated temperature in buildings are common in Canada, similar steps need to be taken to prevent overheating. He feels proactive steps, particularly in older buildings and long-term care and seniors’ facilities, need to be taken.
Bringing passive cooling to Canada is addressed by The Atmospheric Fund in an article by Taric Somani published last September as the country reflected on the heat of the 2025 summer.
“Designing for resilience is imperative. The importance of designing urban environments that mitigate extreme heat cannot be overstated,” Somani writes.
“Designing resilience and efficiency shouldn’t be seen as a burden, but rather as a long-term investment in healthier communities, stronger infrastructure and a more sustainable environment. Thoughtful and integrated urban planning and design directly shape how we live.”
It’s not a discussion restricted to Canada by any means. In Europe, the number of days when the heat exceeds 30°C has risen sharply over the past 40 years. While about 90 per cent of North American homes have air-conditioning, the number is far lower in Europe, about 40 per cent in Spain and only 25 per cent in France.
It has even resulted in political posturing. France’s far-right leader Marine Le Pen has reportedly said that should her party come to power, it would deploy a “major air-conditioning equipment plan” around the country. In response, Marine Tondelier, head of France’s Green Party, instead suggested solutions to make cities passive and greener and buildings more energy-efficient.
Old, simple methods have proven effective. In Spain for example, white fabric awnings stretched across narrow streets provide shade and reduce temperatures by several degrees. In the Middle East, shutters and grills on buildings have, of course, been part of design for centuries. Only recently has the Western world caught on to such passive measures.
If urban planners and building owners need proof and inspiration for effective passive cooling measures, they can look to Singapore.
As the BBC reports, “Almost half of Singapore is covered in grasses, shrubs and broad-canopied trees, throwing cold water on the idea that cities can’t spare room for nature as they grow.”
In addition, Singapore has had covered sidewalks for over a century, since they were written into the town’s official plan in 1822 by British colonial official Stamford Raffles.
In the U.K., MacFarlane Place, a 142-unit affordable housing redevelopment in the London district of Hammersmith, won notoriety for its use of electrically-powered window shutters to control solar gain and temperature. Using the shutters reduces to a great extent the need for energy-intensive air conditioning by allowing residents to naturally regulate the internal climate of their homes during peak periods.
Triple-glazed windows, along with their size and positioning, were also part of the plan to control solar gain. The MacFarlane Place project managers explained a glazed south westerly aspect enhances the solar gain effect, while protection from cold northeasterly winds was achieved with new tree plantings and windbreaks.
As is often said, “Everything that was old is new again.”
This could, in fact, be a guiding path to the passive cooling of North American cities. After all, indoor air conditioning has negative environmental implications and outdoor air conditioning simply isn’t a feasible option.
John Bleasby is a freelance writer. Send comments and Climate and Construction column ideas to [email protected].
