Jun 2022

Extreme Heat Events: Prevention & Resilient Communities

Digital depiction of an urban landscape with people walking with trees surrounding the path, a solution to protect against extreme heat — Photo Credit: The Canadian Society of Landscape Architects

As we approach the one-year anniversary of British Columbia’s record-setting heat dome, a new report by the BC Coroners Service, Extreme Heat and Human Mortality: A Review of Heat-Related Deaths in B.C. in Summer 2021, aims to prevent heat-related deaths in the future. Alex Boston, Executive Director of Renewable Cities, served on a panel appointed by B.C. Chief Coroner Lisa Lapointe to review the hundreds of deaths following British Columbia’s extreme heat event that occurred June 25 – July 1, 2021.

While strengthening emergency management and response to extreme heat events is important, it’s also critical to focus on prevention and creating socially connected, healthy, climate-resilient neighbourhoods.

Prevention strategies should identify and effectively manage long-term risk factors that increase vulnerability to extreme heat, such as the growth in one-person and senior households, rapidly declining urban tree canopies and current low levels of home retrofit activity.

Recommendations to prevent catastrophic heat-related mortality events include:

Reverse the urban heat island effect

Neighbourhoods with weak urban tree canopy, low greenspace and extensive concrete and asphalt were associated with heat-related mortality during the 2021 heat dome.

Protect and restore the urban tree canopy in neighbourhoods and create more accessible greenspaces
Create cool parks with abundant tree canopy, water features and shaded places to connect within a short walk from medium density and greater neighbourhoods

These priorities should be integrated into provincial commitments to craft a “Climate Lens” for Official Community Plans and Regional Growth Strategies and update the Local Government Act.

Reduce isolation

One-person households (56 per cent) and the elderly (men over 60 years old and women over 70) were disproportionately represented in the mortality record.

Encourage development that supports secondary suites in single detached homes.
Support programs run by non-profit housing providers that foster social interaction for interested seniors that have a secondary suite. For example, offering discounted rent in exchange for basic services such as cooking, shopping, yard work, dog walking, etc.

Design, build & adapt for cooling

Landscape and building design strategies support cooling, including green and blue roofs, green walls, trees and water features, canopies, white roofs, insulation and thermal towers
Adopt a target to capture and clean most rainfall on site to support trees and greenspace that provide shading and retain water for cooling through evapotranspiration
Homes not able to be cooled through passive design should include air conditioning. Optimal systems are heat-pump driven, providing heating, cooling and air filtration services, and ultra-energy efficient.

These priorities should be integrated into the next Building Code and the new retrofit code under development (i.e. the Alterations Code for Energy Efficient, Resilient Buildings).

Multiple Co-Benefits of Actions

Several smart preventative actions provide additional benefits for communities, including greenhouse gas reductions, addressing affordability and social isolation, increasing energy security during extreme heat events, and creating multi-purpose greenspaces that mitigate climate risks and provide recreation and active travel infrastructure.