When people think of wildfires, burning trees is probably the first image that comes to mind.
So when a city burns and trees are left standing, it may seem unusual at first glance.
Several wildfires have swept through Los Angeles since Tuesday, killing at least 10 people and burning down more than 10,000 homes and other structures in a 40-kilometer stretch north of downtown.
As images of the fires dominate the media this week, some are questioning why trees, including the state's iconic palms, have survived next to homes and burned cars.
This is encouraging conspiracy theories on social media of homes and structures being targeted – with some saying there is no way a fire would have left trees standing naturally and suggesting that secret weapons directly attacked structures.
Internet personality The Patriot Voice posted to his 141,000 followers on social media platform X that photos showing standing trees provide proof that the US government is “setting fires to deliberately using Military grade DEWs (direct energy weapons) in these areas to initiate a MASSIVE LAND GRAB. “
Others have said it is evidence of HAARP (High Frequency Active Auroral Research Program) microwaves, with one user X saying they “burn towards metal” in homes, but, ” Trees don't have metal inside, so it's harder for trees to burn. from a microwave.”
Mads Palsvig, head of Denmark's right-wing Prosperity Party, wrote on X, “Forrest (sic) fires where trees don't burn. It's called DEW. Always very good places.”
It all depends on humidity
The claim that trees are not burning is simply not true, as can be seen from several videos and photos showing that many have gone up in flames, in some cases causing damage to nearby buildings.
But scientists say there is a simple explanation why some have been spared that fate.
“I mean, it's very obvious to me. Trees are filled with thousands and thousands of liters of water,” said biology and biotechnology professor Miranda Hart, with the Okanagan Institute for Services Biodiversity, Sustainability and Ecosystems at the University of British Columbia.
“Of course trees burn when fires are big and hot enough. But if there is a tree full of water and something dry next to it, the dry thing is going to burn first. So, you can imagine that the fire might just go around if there's enough fuel on either side of it.”
Similar questions arose after the town of Paradise, Calif., burned to the ground in a 2018 wildfire. At the time, the U.S. Forest Service had resigned a scientist told CBC News Although some people might think of a wildfire as a wall of flames, burning embers ignite many spot fires over a wide area – which helps explain why in some photos, it was It almost looked like there were hundreds of house fires rather than one big fire. .
After a wildfire in 2007, the fire department in Escondido, California, proposed restrictions for the planting of palm trees especially after confirming that some species, due to their shape or lack of maintenance, especially dangerous.
Palms that are not well maintained can “explode into a giant flame,” the document says, a phenomenon seen in videos from the current LA wildfires. He says flying embers can embed themselves into the fibrous material or leaf bases throughout the trunk of a palm tree.
Another major hazard is leaf bases and dried fronds on unmaintained trees can detach from the trunk and be carried on the wind, acting as a fireball.
Kevin Hanna, director of the Center for Environmental Assessment Research at UBC, said some trees are more susceptible to fire than others – deciduous trees and shrubs, for example, are less flammable because of their moist leaves and lower resin content. , while conifers are ornamental. Cedar or juniper is highly flammable.
The fires in LA continue to spread at an alarming rate, kept burning by an abundance of fuel and powerful winds – conditions BC is also familiar with. As Michelle Ghoussoub reports, wildfire experts say the situation holds lessons about preparing for B.C.
As for why some trees and buildings survive while others don't, he said it often comes down to exigent circumstances, and “what some might call chance or serendipity,” such as quick movement in wind that could redirect embers.
Maintaining a wet lawn, or a wet or fireproof roof can make a difference, Hanna said, although in extreme enough situations, almost everything will burn.
“There is no conspiracy – just some politicians seizing unique opportunities, denying the reality of climate change and shifting the blame to others in the hope of profit get big,” he said.
Climate change, development adds to risk
Hanna said housing development has expanded further into fire-prone areas in recent years, increasing the risk of house fires, while wildfires are becoming larger and more frequent, in part because due to drought and warmer weather exacerbated by climate change.
While some have blamed a lack of fire protection and brush removal, UBC's Hart said the reality is that the conditions were perfect for the fires to spread and that not much can be done to prevent similar destruction in the future as well as trying to reverse climate change.
“Fire isn't that mysterious. It just needs the right conditions and the right fuel,” Hart said.
“We can rearrange the deck chairs on the Titanic for a few more years, but we can't build a society that can handle climate change. It's too powerful and it's too multifaceted.”
