Bud Mortenson

Email: bud.mortenson@ubc.ca


UBC professor explains how temperature, fuel and climate change contribute to wildfire risk

Summer is upon us in the Okanagan Valley, and unlike summers in recent past, the majority of the Okanagan’s fire danger rating is sitting at low to moderate.

But, with long-range weather forecasts predicting little precipitation and a rise in temperatures, we asked UBC’s David Scott his opinion on the fire risk in our area.

Scott is an associate professor in earth, environmental and geographic sciences at UBC Okanagan and a Forest Renewal British Columbia Research Chair in Watershed Management.

The Okanagan is one of the most wildfire-prone areas in all of Canada – why is this the case?

Simply put, the Okanagan is a semi-desert area in a rain shadow. Because of this lack of precipitation, we are vulnerable to fire because we are dry, and also because we have built up fuel loads by decades of fire suppression.

What factors are local experts looking at when examining this year’s wildfire risk?

Wildfire risk comes from a combination of weather and fuel factors – so that’s what we’re focussing on right now. In our province, fuels are abundant in most areas, so the risk is driven by weather throughout the fire season – particularly temperature, as that drives evaporation, and rainfall.

We’ve had active fire seasons in the Okanagan the past few years, but when we look back to the disastrous fire season in 2003, that was, at the time, both the hottest and driest season on record at almost every southern interior weather station. Hot summers dry out fuels, which increases our wildfire risk. Which means that fires start more easily and are more likely to spread.

Has climate change altered the Okanagan’s forest fire season?

We know that the climate of Canada is warming. The federal government recently released Canada’s Changing Climate Report – where data analysis showed that human influence has caused Canada’s climate to warm, and it will warm further in the future. It also showed that warming and future warming in Canada is on average about double the magnitude of global warming.

So, what that means for us is that summer starts earlier, summer is longer and there’s more opportunity to dry out the environment, so the fire danger is going to be greater overall. That’s not to say we won’t have cooler or damp summers in between – climate is always variable – but for the big picture and the long-term situation, we’re going to be dealing with greater fire danger and nastier wildfire seasons.

In your opinion, what will the 2019 wildfire season look like in the Okanagan?

It’s really difficult to predict what the season will look like because it all depends on the weather. We’ve had a fair bit of rain in the past couple of weeks, so that’s positive because it’s moistening our fuels.

But that can and likely will change very quickly – just looking at forecasts for next week we can see that temperatures are rising – but the thing about long-range forecasts is, the further out we’re projecting, the weaker our predictions become. So we’re really waiting to see what mother nature will do.

What efforts have been undertaken by the province to mitigate wildfire risks this season?

The province has recently put money into an organization called the Forest Enhancement Society of BC. The society has multiple purposes, but one of those is to prevent and mitigate the impact of wildfires. Through this organization, communities are getting encouragement and assistance to manage their wildfire risk in the so-called urban-wildland interface, largely through the reduction in fuel loads.

What can the public do to improve their preparedness for this year’s wildfire season?

Two words: Fire Smart. It is is a program that’s full of straightforward and practical advice for homeowners on how to clean up their properties in preparation of wildfire season. I’ve heard firefighters say, “if you own the fuel, you own the fire,” and that’s them voicing their frustration for people who make choices without considering where they live. People need to take responsibility for their land and manage their fire risk. Think about what you’re planting right up against your home – junipers and cedars are like wicks. Think about where and how you stack your firewood. The public shouldn’t feel like they’re helpless – there’s a lot they can do to help themselves.

About UBC's Okanagan campus

UBC’s Okanagan campus is an innovative hub for research and learning in the heart of British Columbia’s stunning Okanagan Valley. Ranked among the top 20 public universities in the world, UBC is home to bold thinking and discoveries that make a difference. Established in 2005, the Okanagan campus combines a globally recognized UBC education with a tight-knit and entrepreneurial community that welcomes students and faculty from around the world.

To find out more, visit: ok.ubc.ca.