Air conditioning will not solve future heating domes: experts

Written by Javed Iqbal

Hundreds of people who died during the historic heat wave in British Columbia last summer died in homes unsuitable for temperatures rising to the high 30s and on for days, a report from BC’s coroner’s office found this month.

It was hot outside, but inside it was often much warmer with tragic consequences.

Of 619 deaths in connection with the heat, 98 percent occurred indoors, the review from the coroner’s service shows.

Only one percent of the victims had air conditioners on at the time.

But a year later, experts warn residents and politicians need to think beyond air conditioning as the predominant solution to the risks, as climate change fuels heat waves, as scientists say, becoming warmer and more frequent.

“What I worry about is that we are talking about mechanical ventilation as this umbrella measure for all buildings, and it is hugely problematic if that is what we ultimately end up doing,” said Adam Rysanek, assistant professor. in Environmental Systems at the University of British Columbia University. School of Architecture.

“We want to get completely used to this air-conditioned community,” with windows closed all year round, said Rysanek, director of the research group for building decisions at the university.

Alternative answers can be found in how buildings and cities are designed, laid out and even colored, as brighter surfaces reflect more of the sun’s energy, he said.

Two-thirds of those who died during the extreme heat last summer were 70 years or older, more than half lived alone, and many lived with chronic illnesses.

Rysanek said it is important to ensure that such vulnerable people have access to air conditioning when temperatures become dangerously hot.

But many sources of overheating in buildings stem from design and performance, and the focus on air conditioning ignores proven solutions, he said.

Urban planners and the construction industry should use brighter colored materials for buildings and even paved roads, he said, in addition to adding shade to the building’s exterior.

“At the peak of heat, much of the cooling demand comes from solar energy received on the outside of the building. Let’s reflect that away.”

Alex Boston, who served on the forensic pathologist’s assessment panel, said “underlying vulnerabilities” to hazardous heat are growing in BC and across the country as a result of demographic change and how housing and communities have been built.

The number of people over 65 and people living alone is on the rise, and both of these characteristics increase the risk of extreme heat, said Boston, executive director of the Sustainable Cities Program at Simon Fraser University.

“On top of that, it’s solo seniors who have chronic illnesses, and then there are even seniors who have some form of material or social deprivation,” he said.

“It could be income, it could be the nature of their home and the neighborhood they live in that (could) have insufficient tree canopy. All of these factors come together and we have to work on many of them at the same time. “

Failure to ensure that buildings are surrounded by trees to provide shade and evaporative cooling would be “to shoot ourselves in the foot in terms of the energy load and cooling needs of a building in the future,” Rysanek said, calling for “very robust” requirements for vegetation and landscaping to mitigate extreme heat.

Metro Vancouver aims to increase its urban tree crown to 40 percent by 2050, up from an average of 32 percent across the region, although a 2019 report noted that the existing crown was declining due to urban development. The goal for the city of Vancouver is specifically to increase the canopy from 18 to 22 percent.

Boston said there are significant co-benefits of many of the measures to improve heat resistance, such as the restoration of urban trees.

Trees and vegetation help reduce the risk of flooding, he said, and neighborhood parks serve as social hubs that can facilitate social isolation and foster a sense of community.

“We have complex problems, and if we only look at one isolated component, we are not maximizing the benefits of solving those problems in an integrated way,” Boston said.

For example, Boston’s organization is working on a project on Vancouver’s North Shore to consider how social service providers can help older single people manage secondary suites in their homes, an approach he said could ease affordable housing while reducing risks by stay alone under extreme heat.

“We need to address more,” Boston said.

Meanwhile, a 2020 study and report from BC’s water and power authority found that the use of air conditioning in homes had more than tripled since 2001.

Many residents added an average of $ 200 to their summer bill by using air conditioners inefficiently, with nearly a third of survey respondents setting the temperature below 19 C. Popular portable devices use 10 times more energy than a central air conditioner or heat pump, the report said. .

Globally, the International Energy Agency in 2018 expected that the energy demand from air conditioning would triple by 2050.

Continuing on that path would make it difficult for governments to achieve greenhouse gas reduction targets to mitigate climate change, Rysanek said.

“If we exacerbate this problem, building development costs are a drop in the bucket in terms of the climate impacts we are going to face,” he said.

The BC government should encourage non-mechanical cooling options to spur their introduction into residential and commercial buildings, he said, pointing to measures such as natural ventilation, ceiling fans and radiant cooling built into floors or ceilings, all of which would cool residents before turning. on an air conditioner.

“We should encourage our policy makers to realize that there is a big world out there of alternatives. We may not have the suppliers here yet in BC, but it is a great opportunity for business,” Rysanek said.

Companies around the world have implemented these refrigeration alternatives in Europe, in Asia and elsewhere, and “we should try to invite them here so we learn about these things, as the public, as consumers,” he said.

The forensic pathologist’s report calls on BC to ensure that the building regulations from 2024 incorporate passive and active cooling requirements in new homes along with cooling standards for renovation of existing homes and to ensure that “climate change lenses” are adopted in regional growth strategies and official community plans. .

It also recommends that the province consider how to issue refrigeration devices such as medical devices to those most at risk of dying from extreme heat.

Public Safety Minister Mike Farnworth has said the government will consider the report and “take the necessary steps to prevent heat-related deaths in the future.”

It’s hard to predict how often BC may see a repeat of last summer’s highest temperatures, but climate change will undoubtedly cause heat extremities to rise in frequency and size, said Rachel White, an assistant professor in the Department of Earth, Oceanic and Atmospheric Sciences. at the University of BC

“When we have a normal heat wave in the future, it will be warmer than we have been used to,” she said.

A heating dome refers to a high-pressure area that settles in when the temperatures below get warmer, White explained.

These regions sometimes become “quasi-stationary”, depending on factors such as the strength of the winds circulating high in the atmosphere, she said.

When the heat dome covered BC last year, its effects were amplified by soil already hit by drought, lacking moisture that would evaporate and help cool the country during the long summer days with clear skies, she said.

“Earth’s atmosphere is not in equilibrium,” White warned, “and the longer we continue to turn off these greenhouse gases, the more and more warming we will see.”

“We have to act now if we do not want it to be terrible in 40, 50 years.”

This report from The Canadian Press was first published on June 25, 2022.

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Javed Iqbal

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