Climate Shift Index Alert•May 1, 2024
Warmer than usual weather in British Columbia — linked to climate change — could exacerbate fire weather conditions
UPDATE: Climate Central released a Climate Shift Index (CSI) alert for British Columbia on May 1, which forecasted warmer-than-usual early May temperatures linked to climate change. Over the four days of the heat event, temperatures soared 6°C-7°C above normal, with a CSI value of 5, indicating this heat was at least five times more likely due to human-caused climate change. |
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An unusually warm forecast, beginning today, in parts of British Columbia — found to be 5 times more likely because of climate change — sets the stage for increased potential wildfire risk this week.
Climate Central analysis shows that the unusually warm temperatures forecast over May 2-5, 2024 in British Columbia are influenced by human-caused climate change. Across much of the province, climate change is making those temperatures at least five times more likely. In some larger cities in British Columbia, climate change is making those temperatures 2-3 times more likely. After a record fire season in 2023, this analysis shows climate change is warming up temperatures once again.
Note: This event may continue beyond May 5. Use the global Climate Shift Index map to stay updated on unusual temperatures in your region.
How unusual are the forecasted temperatures?
During this four-day period, forecast daily average temperatures are up to 5°C warmer than the average (based on 1991-2020 climate normals) in British Columbia.
What impact could these temperatures have?
The unusually mild temperatures could exacerbate widespread and worsening drought conditions occurring across British Columbia, which are already at exceptional levels in parts of central British Columbia. In turn, the unusual warmth could bolster the spread of wildfires burning across the province.
As of March 31, 85% of the province was classified as “abnormally dry” or in “moderate to exceptional drought”. Ongoing drought conditions could further fuel the more than 100 active wildfires in British Columbia.
Drought not only transforms grasses and trees into kindling but also can increase both the likelihood of fire ignition and the rate at which wildfires spread, which, in either case, potentially overburdens firefighting capacity and resources.
Elevated temperatures exacerbate drought conditions and fire risks. Some locations in British Columbia will reach the highest category of the Fire Weather Index (from Natural Resource Canada) on May 3.
Additionally, British Columbia’s lowest average snowpack in more than 50 years may further increase the risk of drought and wildfire this spring and summer.
Wildfires and wildfire smoke pose myriad risks — including threats to human safety, destruction of homes and businesses, degradation of air quality, damage to ecosystems and displacement of wildlife, and interruption of power and transportation services.
The 2023 fires were costly, with $720 million in insured losses reported. British Columbia’s fire suppression costs reached $817 million. In 2023, 2.84 million hectares burned across British Columbia — more than double the area of forest and land that was burned during any previous year on record.
Wildfires further contribute to climate warming through the release of massive amounts of carbon and other greenhouse gasses into the atmosphere.
How has climate change influenced these temperatures?
Daily average temperatures are expected to reach Climate Shift Index (CSI) levels of 5 across the western half of British Columbia, covering an area of ~126,742 km². A CSI level 5 indicates that human-caused climate change made these above-average temperatures at least five times more likely, signifying an exceptional climate change event.
The regional districts with the most unusual temperatures and the highest CSI levels include Stikine and Kitimat-Stikine (including the Spatsizi Plateau Wilderness Provincial park) and portions of western Peace River.
Over 2.8 million people across cities in southern British Columbia will be exposed to at least one day above CSI 2.
Use the global Climate Shift Index map to see CSI levels in your city and region, and see our FAQs to learn about the CSI.
City | Date of peak temperature anomaly | Forecast peak temperature anomaly (°C above normal) | Forecast high temperature that day (°C) | Forecast peak CSI level |
|---|---|---|---|---|
Vancouver | 5/4/24 | 2.9 | 13.8 | 2 |
Burnaby | 5/4/24 | 2.9 | 13.8 | 2 |
Surrey | 5/4/24 | 3.1 | 14.0 | 2 |
Coquitlam | 5/4/24 | 3.1 | 14.0 | 2 |
Richmond | 5/4/24 | 1.2 | 12.3 | 1 |
Kelowna | 5/4/24 | 3.1 | 12.0 | 2 |
Abbotsford | 5/4/24 | 1.8 | 12.6 | 1 |
Langley | 5/4/24 | 1.8 | 14.1 | 1 |
Delta | 5/4/24 | 1.0 | 12.9 | 1 |
Kamloops | 5/4/24 | 3.1 | 12.6 | 2 |
Table 1. Cities with populations over 100,000 with CSI levels of at least 1.
Additional studies on attributable wildfires in Canada
May 2023: Last year, the Union of Concerned Scientists published a study that found that 19.8 million burned acres — over a third of the total area burned by forest fires in the western United States and southwestern Canada since 1986 — were attributable to emissions from major fossil fuel companies.
August 2023: In a study released by World Weather Attribution last year, it was determined that climate change more than doubled the likelihood of extreme fire weather conditions in eastern Canada, which led to over 13 million hectares of burned land, and raised air quality to hazardous levels in Canada as well as the midwest and northeastern regions of the United States.
What do experts say?
Dr. Andrew Pershing, VP for Science at Climate Central, said:
“The unusually warm conditions expected in western Canada this week are eerily similar to the conditions that we saw at the start of last year’s record fire season. As long as humans keep burning coal, oil, and gas, heat and fire risk will continue to grow.”
How do we know climate change is influencing these temperatures?
The Climate Shift Index uses peer-reviewed methodology to estimate how climate change has increased the likelihood of a particular daily temperature. It can be run using historical or forecast temperatures.
Using computer models, we compared the likelihood that these temperatures would occur in a world without carbon emissions released by humans, versus in today's world with decades of carbon emissions building up in the atmosphere. This is an established scientific method to determine how much climate change has or has not affected individual extreme weather events.
For this analysis, temperatures come from the National Center for Environmental Prediction’s Global Forecast System.
To request an interview with a Climate Central scientist, please contact Peter Girard at pgirard@climatecentral.org
Reporting resources
Until greenhouse gas emissions end, heatwaves everywhere will continue to become hotter and more dangerous. Explore quick facts and local analyses on the links between climate change and extreme heat in:
Climate Central’s Extreme Weather Toolkit: Extreme Heat
World Weather Attribution’s guide to reporting on extreme heat and climate change
Yale Climate Connections’ summary of the connection between heat waves and climate change.