National Issues Report Identifies Growth, not Climate Change, as Major Cause of Increased Severe Weather Losses in Canada

Canada in a Changing Climate: National Issues Report by the Government of Canada has just been released and it reviews the cause of rising extreme weather costs (link: https://changingclimate.ca/national-issues). A previous post looked at the impact of growth on increasing losses in Canada over past decades (https://www.cityfloodmap.com/2018/06/catastrophic-losses-in-canada-have.html) - this new report does the same.

The National Issues Report speaks to the cause of increasing losses in Canada directly, considering growth and contradicting common media explanations for the rise, as indicated below:

Page 349 (my bold):

"Costs related to extreme weather events are increasing (see Section 6.4)

Costs associated with damage from extreme weather events in Canada are significant and rising, largely due to growing exposure and increasing asset values. The scale of costs suggests that households, communities, businesses and infrastructure are not sufficiently adapted to current climate conditions and variability."

Page 365:

"6.4 Costs related to extreme weather events are increasing

Costs associated with damage from extreme weather events in Canada are significant and rising, largely due to growing exposure and increasing asset values. The scale of costs suggests that households, communities, businesses and infrastructure are not sufficiently adapted to current climate conditions and variability.

The number of extreme events has increased since 1983, although the distribution of these events across Canada varies significantly, with Alberta being affected the most. Studies on the attribution of such events in Canada indicate that climate change is increasing the likelihood of certain types of extreme weather events, and may be playing a role in the trend of growing losses from such events. However, the majority of rising losses related to extreme weather events are the result of growing exposure and rising asset values. The scale of costs suggests that there is an adaptation gap or deficit, whereby households, communities, businesses and infrastructure are not sufficiently adapted to current climate conditions and variability."

And on page 372:

"Since 1983, the increasing trend in insured losses associated with extreme weather disasters in Canada has primarily been due to an accumulation of value (e.g., people, assets, wealth) year-on-year. But rising losses cannot entirely be explained by growing exposures, asset values and general price inflation—climate change may be playing a role. While a rise in normalized losses is not “proof” of climate change, it is certainly consistent with the anticipated intensification of some weather extremes with rising temperatures (Swiss Re Institute, 2020; Coronesea et al., 2019; IPCC, 2013)."

Opportunities for improvement?

The National Issues Report report does not speak to the effects of urbanization on increased flood risks. Reporting at the CBC has in the past identified a changing climate as the main driver for increasing damages, discounting the influence of other factors. See post: https://www.cityfloodmap.com/2020/06/yes-were-getting-more-extreme-rainfall.html

- if the cause of increased flood damages is not related to more extreme rainfall, then more focus could be given to adaptation as opposed to mitigation

The Radio Canada Ombudsman has reported numerous accuracy issues in past reporting that claimed climate change effects were driving increasing losses, and Radio Canada management has taken the rare step of deleting the article:  https://www.cityfloodmap.com/2020/11/radio-canada-ombudsman-finds-standards.html

- the new National Issues Report supports the Radio-Canada decision to delete its June 3, 2020 article that stated "Contributing factors to higher claims include higher property values, building onto known flood plains and building over green spaces and wetlands that help absorb rain mitigate flooding. Still experts say the extreme weather and flooding is the main factor says Natalia Moudrak, director of climate resilience at the Intact Centre."

- while higher property values were identified as a contributing factor in that Radio Canada reporting, extreme weather was cited as the main factor. In contrast, Canada's National Issues Report refers to the same data, normalized for growth, and finds: "Since 1983, the increasing trend in insured losses associated with extreme weather disasters in Canada has primarily been due to an accumulation of value (e.g., people, assets, wealth) year-on-year." The new report indicates "climate change may be playing a role", suggesting a lesser and uncertain influence on losses, contrary to the Radio Canada reporting.

Limitations in early losses estimates have not been considered and could affect normalized loss trends. The ICLR noted in its 2018 Cat Tales newsletter that prior to 2008 that data was 'cobbled together' and not very robust (see page 5 article "Big data? How about just starting with data?": https://issuu.com/iclr/docs/cat_tales_march_april_2018

- if lower early loss reporting is accounted for, the normalized increasing trends in losses in the new report would be lower, likely making Canada's trends fall in line with other studies with more robust early data that show losses normalized for growth actually can be decreasing over time.

Hay River Flooding - Strategic Retreat from Floodplains to Manage Flood Risk

Hay River flooding has occurred in the past during spring break up. In 1963, Main Street flooded during spring break up - according to the Hay River Museum, this resulted in 'strategic retreat' from the floodplain whereby many of the residents consequently moved out of the floodplain and established a new area of town.

Hay River Flood

Strategic or managed retreat can be considered when risks are high and flood mitigation efforts or flood proofing efforts are not feasible. A paper Managed Retreat from High-risk Flood Areas: Design Considerations for Effective Property Buyout Programs by Jason Thistlethwaite, Daniel Henstra and Anna Ziolecki (link: https://www.jstor.org/stable/resrep24935?seq=1#metadata_info_tab_contents) notes that "Managed retreat through property buyouts is widely regarded as an effective disaster risk reduction strategy."

The paper notes that cost-benefit analysis may be used to evaluate eligibility for buyout programs:

"Cost-benefit analysis — a method for assessing the economic efficiency of public policies — is often used to project whether the benefits of reducing future disaster losses exceed the costs of acquiring a property. Other criteria used to assess eligibility include damage thresholds (for example, estimated repair costs exceeding 50 percent of a property’s value) and geography (for example, properties located in the 1-in-50 flood zone). The former criterion was used to assess eligibility for buyouts in Quebec in 2017 and New Brunswick in 2019 (Adriano 2019; CBC News 2019), whereas the latter is currently being considered for the buyout program in Grand Forks, British Columbia (Grand Forks 2019)."

More recently in Ontario, 380 cottages /homes on Toronto Island were removed from this historically flood-prone land - see previous post: https://www.cityfloodmap.com/2017/09/toronto-island-flooding-2017-were-lake.html

In Markham, Ontario, flood prone properties on a tributary of the Don River were purchased in order to restore the floodplain and provide storage to attenuate downstream flooding. The business case for the flood control strategy was developed in the Municipal Class EA study that identified the preferred solution including managed retreat - a summary presentation is provided at this link: https://cleanairpartnership.org/cac/wp-content/uploads/2019/09/1.-FINAL-190927-Clean-Air-Partnership-Don-Mills-Channel-Flood-Control-Muir.pdf