Forest Fires Intensify. Here’s Why and What Can Be Done.


By nearly every metric, wildfires in the western United States are getting worse. They grow, spread faster and reach higher, scaling mountain heights that were previously too wet and cold to support such fierce fires.

They also become denser, killing more trees and removing entire chunks of forest.

“Ten years ago, we didn’t really see fires moving like this,” said Lenya Quinn-Davidson, a fire consultant for the University of California Cooperative Extension, referring to the Bootleg Fire, which started on July 6 in 2021 and was consumed more at one point. more than fifty thousand acres in one day.

Here’s what’s driving these changes and what can be done about it.

Forest fires require a spark and fuel. Half of wildfires in the United States are started by lighting. The other half is human-caused—usually started by power lines, cigarettes, cars, campfires, or arson.

In recent years, there has been an abundance of very dry fuel. Drought and high heat can kill trees and dry up dead grass, pine needles and other materials that act as kindling when a fire sweeps the forest at the bottom of the forest floor.

Wildfire experts see the signature of climate change in the dryness, high temperature and longer fire season making these fires more extreme. “Without climate change, we wouldn’t have seen such a rapid increase in fire activity,” said Park Williams, a climate scientist at UCLA. “There is no way.”

These conditions were exacerbated by firefighting policies. Prior to the modern settlement of the American West, woodlands in the area were naturally burned by lightning or deliberately burned by indigenous communities as a form of forest maintenance. But for the last hundred years, most Western states have suppressed the fires. This has led to increasingly dense forests and extensive undergrowth on the forest floors.

“We’re ready to fire,” said Miss Quinn-Davidson.

Al Lawson, the Rogue Fire incident commander in Oregon, specification Its behavior as “one of the most extreme you can find”. But what does this mean?

Experts consider fires according to criteria such as intensity, rate of spread and severity.

Fire density refers to its strength or the energy released from its flame. Satellites measure the energy and temperature of fires, and research has shown that these flames increase in strength.

The rate of spread is one of the most important factors, as it suggests that a fire may be less predictable. While the size or area of ​​a fire is important, Ms. Quinn-Davidson said it’s more important to watch how fast it moves.

Violence refers to the consequences of a fire, for example, how many trees were killed. If a fire is long and burns to the tops of trees and kills them, it may be more difficult to control.

Breathing in wildfire smoke is risky.

Like air pollution, wildfire smoke — and especially PM 2.5 concentration, or particles smaller than 2.5 microns — can affect the respiratory and cardiovascular systems, said Colleen Reid, an environmental epidemiologist and health geographer at the University of Colorado Boulder.

In healthy people, smoke can cause a sore throat, cough, shortness of breath, or decreased lung function. Those already suffering from cardiovascular or respiratory diseases are at risk of exacerbations and should take extra precautions even when air quality is considered moderate.

Scientists are still studying the chemical composition of wildfire smoke depending on what is being burned.

For example, trees and biomass produce a combination of carbon dioxide, methane, and nitrogen oxides, while burning houses or cars can produce a wide variety of compounds, including heavy metals.

Dr. Reid said the first step towards conservation is to monitor the air quality where you live using resources such as: this map Environmental Protection Agency or Follower of the New York Times.

On days when the air quality is particularly bad, stay indoors, keep windows and doors closed, and use HEPA filters if possible. If you don’t have access to a HEPA filter, there is evidence that installing a quality filter on a box fan can be protective. Outdoors, wear a form-fitting N95 mask.

60 to 90 percent of homes Losses in forest fires are due to embers carried by the wind before the fire. If an ember falls on a house or mulch under a window or enters an attic through a vent, it can catch fire and set the house on fire.

In California, homes built in what has been termed the wilderness-urban interface over the past decade—for example, areas stretching between forests and towns or cities—were required to have fire-resistant features such as fireproof siding and double-sided tempered windows. .

But experts say that for any home, even small steps like keeping gutters and roofs free of leaves and debris can be quite effective. As a next step, it’s worth replacing things like vents with a finer mesh screen or replacing the siding and roofing with more fire resistant materials.

“We have good science showing that homes that are renovated or built this way are more likely to survive wildfires,” said Susie Kocher, a forestry consultant at the University of California Cooperative Extension.

Landscape changes can also make a difference. Firefighters think in terms of Zone 0-5, which refers to the five-metre perimeter around a house. This area should be kept free of debris, firewood, plants or mulch. “It looks nice to put a bush under our window, and that’s definitely wrong,” Ms. Kocher said.

Experts agree that projected burns—intentional fires that periodically clear bush or other fuel—are key to reducing the severity of future wildfires. State and federal agencies have already committed to performing more prescription burns.

But experts also emphasize that there should be more federal and state legislation that prioritizes this technique. There are currently bills in the U.S. Senate and California House to provide more funding and education for prescription burns.

Another important step is to take care of the landscape to clean up dead trees and other fuels. After a massive death toll in the Sierra Nevadas in the 2010s, an estimated 150 million trees fell, but only 1 percent of those trees were removed, creating more fuel for future fires.

But experts say a long-term solution requires major changes. More importantly, the mentality needs to shift from fighting fires to reducing the risk of extreme events that make fires worse. “For a long time we treated fire as if it was something we could fight. “We don’t fight hurricanes or earthquakes or floods,” said Ms. Quinn-Davidson. We need some radical changes in the way we do things to adapt, but yes, I think we can.”


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