Times Colonist

Summers to get much hotter by 2050s: report

- BILL CLEVERLEY Times Colonist

Hot summer days in Greater Victoria will increase dramatical­ly by the 2050s, say climate researcher­s in a report prepared for the Capital Regional District.

“Our region can expect the number of summer days above 25 C to triple, from an average of 12 to 36 days per year,” says the report.

The one-in-20-year hottest day temperatur­e is projected to rise from 32 C to 36 C by the 2050s.

The changes will occur unevenly over the seasons, meaning some winters will be warm, while others will be colder, and some summers will be cold and wet, while others are hot and dry, the researcher­s say.

The report was prepared by Gillian Aubie Vines from Pinna Sustainabi­lity, and Trevor Murdock and Stephen Sobie, from Pacific Climate Impacts Consortium.

The researcher­s assumed no change in current levels of greenhouse-gas emissions for the rest of the century in projecting impacts to the 2050s.

The report suggests the CRD can expect: • warmer winter temperatur­es • fewer days below freezing • more extreme hot days in summer • longer dry spells in summer months • more precipitat­ion in fall, winter and spring • more intense, extreme weather events

Warmer winters mean the region will experience a 69 per cent decrease in the number of frost days, creating a “new normal” climate in which Greater Victoria will be almost entirely frost-free at lower elevations.

Rising temperatur­es will result in a 22 per cent increase in the length of the growing season by the 2050s, says the report.

Annual precipitat­ion is expected to increase by a modest five per cent by the 2050s and 12 per cent by the 2080s, the report says, noting that most of the increase will come in the fall and during increasing­ly extreme weather events.

About 31 per cent more precipitat­ion is expected on very wet days and 68 per cent on extremely wet days, the report says.

“Despite the increased intensity of wet events, the amount of rain in summer is expected to decrease by about 20 per cent, while the duration of dry spells will lengthen by about 20 per cent,” the report says.

Victoria Mayor Lisa Helps called the report an extremely valuable tool for government­s in the CRD.

“It gives us a really solid picture of what the future will look like and that gives us even more impetus to both adapt and mitigate as we build new infrastruc­ture, as we make decisions at all our tables throughout the region,” Helps said.

The projected warming will have implicatio­ns for regional ecosystems, watersheds, agricultur­e and horticultu­re, and communitie­s, says the report.

For example, it notes that the capital region has an aging population and it’s projected that 37 per cent of the population will be 55 years or older by 2021.

Some respirator­y illnesses could be made worse by periods of heat, increased incidence of forest fires and any rise in ground-level ozone levels on days when the temperatur­e rises above 25 C.

“Impacts have the potential to be more significan­t in urban centres due to the urban heat island effect, unless adaptive measures are taken, including air conditioni­ng, cooling stations and an increase in the urban tree cover,” the report says.

The urban heat island effect is the tendency of urban areas to be warmer because of human activities and land modificati­on.

CRD chairwoman Barb Desjardins said the report underlines the need for planning and regional initiative­s “to be put through a climate-action lens.”

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