Science

Canadians are unknowingly buying homes in climate change danger zones, report finds

Canadians are unknowingly buying and building homes and other infrastructure in areas at high risk of flooding, wildfires and other climate change impacts. That could lead to billions of dollars in damage each year if governments don't force sellers to disclose risks and start adapting, a new report says.

Climate change could boost damage costs by billions; more risk disclosure needed for adaptation

Rescue workers help evacuees retrieve some belongings from flooded homes on Wednesday, May 1, 2019 in Ste-Marthe-sur-la-Lac, Que. Damage to buildings from flooding could increase five-fold by 2050 and 10-fold by 2100 to $13.6 billion each year, says a new report from the Canadian Institute for Climate Choices. (Ryan Remiorz/The Canadian Press)

Canadians are unknowingly buying and building homes and other infrastructure in areas at high risk of flooding, wildfires and other climate change impacts. That could lead to billions of dollars in damage each year, says a new report from the Canadian Institute for Climate Choices.

Investing in adaptation could slash those costs — but just about no one has the information they need to be able to adapt, according to the report released last week from the federally funded think-tank

"There's pretty poor understanding of climate risks and really poor risk-disclosure practices across the country," said Dylan Clark, a senior research associate at the institute and co-author of the report, during a media briefing.

There's little to no public information on current flood, wildfire or permafrost thaw risks, he said, let alone taking into account the future of climate. 

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"Information that's readily available to most decision-makers and investors and consumers does not provide enough information to make informed decisions — and that's a key barrier here to adaptation."

For example, publicly available government data from local conservation authorities generally show only areas at risk of flooding due to rivers and coasts, the report said.

Researchers were able to obtain data — available for a fee from a private company, JBA Risk Management — that showed 325,000 buildings in Canada are at risk of flooding from heavy rainfall and another 625,000 are at risk from flooding due to rivers breaching their banks, whose owners "have no way of knowing that their properties are at risk of flooding" the report said.

Even JBA's maps don't have enough detail to identify individual homes at risk. However, the maps do "highlight that there is that [information] gap," said Ryan Ness, the report's lead author.

This image from the new report of the National Capital Region show the risk of a flood so big that it happens once in 100 years, according to publicly available data from local conservation authorities (red) which only looks at river flooding, and data that can be purchased from JBA Risk Management (yellow) which includes storm sewer flooding. (Canadian Institute for Climate Choices/JBA Risk Managenent/)

The report recommends that governments and regulators require owners of existing and proposed buildings and other infrastructure to disclose climate change risks, saying the government should start to generate that information and make it publicly available for that purpose. 

Some federal funding has been allocated in recent years for flood mapping, but the insurance industry has complained that progress has been too slow. Meanwhile, other researchers have found the provinces haven't been moving fast enough either on flood mapping, emergency plans and critical infrastructure protections to adapt to climate change.

How the research was conducted and what it found

The new report combined two main factors:

  • Information about Canada's current buildings, roads, railways and electricity infrastructure.
  • Climate models to estimate future costs of damage from climate change. 

Those climate models included:

  • A "lower emissions" scenario, where the world slashes greenhouse gas emissions enough to limit global warming to a peak between 2 and 3 C compared to pre-industrial times, but 3.3 C by 2050 and 4 C by 2100 in Canada, which is warming faster.
  • A "high emissions" scenario, where emissions continue on their current trajectory; in Canada, that's 4.4 C by 2050 and 7.4 C by 2100.
Hurricane Ida destroys electricity infrastructure at Port Fouchon, La., Thursday, Sept. 2, 2021. In Canada, damage to electrical transmission and distribution infrastructure due to climate change impacts could triple to $4.1 billion a year by 2100, the new report found. (Scott Clause /The Daily Advertiser/The Associated Press)

The study found that under the high emissions scenario, by 2100:

  • Damage to buildings from flooding could increase five-fold by 2050 and 10-fold by 2100 to $13.6 billion each year.
  • Damage to roads and railways due to temperature and rainfall damage could increase to $12.8 billion each year.
  • Damage to electrical transmission and distribution infrastructure could triple to $4.1 billion a year.

However, costs could be cut by reducing global warming through emissions cuts and adaptation to reduce damage from climate change impacts.

"Ultimately, we'll need both adaptation and mitigation," said Dale Beugin, the institute's vice-president of analysis and research and a co-author of the report.

Buyouts in flood zones and other adaptation tactics

The report includes recommendations for steps to adapt Canada's buildings and other infrastructure to changing climate, which would reduce the damage to people's lives and property. They include:

  • Buying out 10 per cent of houses in the highest one per cent of flood-risk areas across the country — about 7,500 properties — at a total cost of $1.9 billion, with the potential to save $200 million each year.
  • To reduce coastal flooding, building sea walls, elevating buildings at risk and shoring up eroding beaches.
  • Altering the materials used in asphalt to withstand higher temperatures and increase the depth of the base layer to withstand heavier rainfall.
  • Installing temperature sensors on railway tracks and adjusting train speeds based on temperatures.
  • Replacing electrical transmission and distribution components with more resilient versions.

The researchers acknowledged that much of that adaptation can't happen without knowing what areas are at risk of damage. 

"The current lack of climate risk information, however, does not justify continued inaction on adaptation," the report says, adding that recent climate-related impacts and disasters provide enough evidence to start moving on the biggest risks and most vulnerable areas.

The Thomas Creek Fire, 1.5 km east of Skaha Lake, is shown near Okanagan Falls, B.C. in this photo from July 2021. While Canadian flood risk maps are spotty and out-of-date, risk maps for hazards such as wildfires largely don't exist at all, researchers say. (Penticton Herald-Mark Brett/The Canadian Press)

Nor does it mean the government can't require disclosure of risks where that information is available, Ness said, so people like homebuilders, homebuyers and insurers can protect themselves.

While there isn't the full scale of information needed for full disclosure of risks, he said, "there is information that's out there that's not being disclosed."

Regulations requiring disclosure could actually speed up the availability of such data, said Beugin. "This also creates incentives to … generate that information and get more information out there."

But will the governments act?

Researchers who study climate adaptation said the report was well done, thorough and timely.

Ann Dale, a professor and the director of the School of Environment and Sustainability at Royal Roads University in Victoria, has previously done research on sustainable infrastructure. She said the report was "exactly what's needed" to show what will happen if governments don't act on adaptation.

She suggested it could even have gone a bit further and specifically recommended solutions that don't just adapt, but actually help mitigate climate change, as many nature-based solutions do.

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Ian Burton, professor emeritus at the University of Toronto's department of geography and planning, who was founding director of the adaptation branch at Environment Canada, said the report's recommendations are good and he's hopeful all three levels of government will act on them.

He noted that the federal government funded the report, saying "I hope that will motivate them a little bit to pay attention."

But the uncertainty about which climate impacts will hit where and when, he said, makes this a challenging problem to tackle.

Even when such reports are commissioned and read by government policy experts, Dale said the pressure to build and repair infrastructure quickly may not allow for new ways of doing things. What's needed now is political will, she said. 

"We know what to do. We have enough new technology … we need political decision-making to move forward."

ABOUT THE AUTHOR

Emily Chung

Science, Climate, Environment Reporter

Emily Chung covers science, the environment and climate for CBC News. She has previously worked as a digital journalist for CBC Ottawa and as an occasional producer at CBC's Quirks & Quarks. She has a PhD in chemistry from the University of British Columbia. In 2019, she was part of the team that won a Digital Publishing Award for best newsletter for "What on Earth." You can email story ideas to emily.chung@cbc.ca.

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