British Columbia

'The new normal'? It's too early to blame B.C.'s floods on climate change, scientists say

Climate change is on the mind of many in B.C. as residents swelter in record-breaking heat and bail out from destructive floods, but scientists say it’s not easy to connect extreme weather events to global warming.

It's tricky to connect one-time events with global climate trends, according to experts

A flooded area of Grand Forks, B.C., is seen in an aerial view on Saturday. (Darryl Dyck/The Canadian Press)

Climate change is on the mind of many in B.C. as they swelter in record-breaking heat and bail out from destructive floods, but scientists say it's not easy to connect extreme weather events to global warming.

It's the second year in a row that parts of the Interior have been hit by massive floods. Last year, of course, the floods were followed almost immediately by wildfires and the resulting loss of plant cover has made some parts of the province even more susceptible to flooding.

But according to Brett Gilley, a professor in Earth, Ocean and Atmospheric Sciences at the University of B.C., it's too early to say whether these events are a direct result of climate change.

"I think climate change is definitely something that we're starting to experience, but it's hard to say this is that," Gilley told CBC.

Over the weekend, several communities saw temperatures soar into the high 20s and low 30s, busting through daily records. Those high temperatures are causing mountain snow to melt rapidly, feeding floods that could hit levels seen only once in 100 years.

Jackson Phipps, 16, has been tirelessly helping to load sandbags in Grand Forks. (Rafferty Baker/CBC)

Public Safety Minister Mike Farnworth told CBC on Monday that there's a "real concern that what we're seeing may in fact become the new normal."

Climate, however, isn't something that's measured in one-time events — or even two- or three-time events.

"When we're talking about climate, we're usually thinking of a 30-year average," Gilley said.

"So five years of weather, for example, isn't necessarily enough for us to say climate has changed, but it's possible."

'Potentially conflicting processes'

And the question of how warming temperatures affect flooding is still very much up for debate, according to Markus Schnorbus, the lead for hydrologic impacts at the Pacific Climate Impacts Consortium in Victoria.

"We have obviously concerns that hydrologic events can become more frequent in the future — both flooding and droughts — so it's something that we are very desperate and anxious to answer," he said.

A man rides a bicycle in the dirty flood water inundating downtown Grand Forks, as a crew sandbags a business in the background. (Rafferty Baker/CBC)

While rising temperatures can lead to sudden snow melt, causing flooding, higher temperatures in the winter could also mean less snow to melt, Schnorbus pointed out.

"There are all these different multiple trends with potentially conflicting processes," he said.

He added that scientists are trying to predict how climate change will affect drought and flood cycles using computer models that take into account everything from projected snowfall, to melting speeds, to summer precipitation.

With files from Vivian Luk.

Interested in learning more about climate change? In the CBC Podcast 2050: Degrees of Change, meteorologist Johanna Wagstaffe explores how our world and lives will adapt to climate change within a few decades.


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