️‍🔥 What are controlled burns?

We’ve all been watching over the last few weeks as Los Angeles experienced its worst-ever wildfire. The statistics are eye-popping:

• over 25,000 acres burned

• an estimated $50B in damage

• more than 10,000 houses destroyed

• 130,000+ people ordered to evacuate

Some people have argued that we can prevent these kind of devastating wildfires with a counterintuitive solution: intentionally starting smaller fires called controlled burns.

Most people think of fire as purely destructive.

But fires are a natural part of how our ecosystems function, and fire ecology experts argue that we need intentional fires to help manage our landscapes.

Controlled burns (also called prescribed burns) are intentional fires set by humans as a form of forest management.

Humans have been doing controlled burns for thousands of years, and it has long provided a natural way of preventing the kind of wildfires that we increasingly see in California.

Controlled burns can also be used to clear lands for farming, as the debris from a fire provides soil-enriching minerals and open space for planting crops. 

During a prescribed burn, forest managers use the wind to “push” a fire toward a natural firebreak (like a river), allowing them to control where the fire burns.

California has always been prone to fires.

Researchers estimate that over 4 million acres burned each year in prehistoric California, purely due to natural factors.

But between 1999 and 2017, the number of annual acres burned fell to just 13,000.

While California does do some controlled burns, the general build-up of flammable plants — plus drought and other factors — has enabled the kind of devastating wildfires that the state has seen in recent years.

Other states, like Florida, actively use controlled burns to manage forests in the Everglades & in other state parks.

Rick Anderson, the former Fire Manager for Everglades National Park, said that Florida burns 2 to 3 million acres every year in controlled burns.

He summed up the logic behind the forest management strategy:

“If we don’t burn it when we can control it, it will burn when we can’t.”

Some experts say that controlled burns would not have prevented the Los Angeles fires, which were caused primarily by extreme winds that can carry embers up to a mile or more.

Jon Keeley, a research scientist with the U.S. Geological Survey, told HeatMap's Emily Potecorvo:

"Fuels are not really the issue in these big fires — it’s the extreme winds.”

Still, that doesn’t mean that these fires weren’t preventable.

The late great Angelino writer Mike Davis famously predicted that wildfires in southern California would get worse & worse, as L.A.’s sprawl grew outward and the natural forces keeping the flames at bay were buried in concrete.

In a 1998 book about the natural history of Los Angeles, Davis wrote:

“Los Angeles has deliberately put itself in harm’s way.

For generations, market-driven urbanization has transgressed environmental common sense.

Historic wildfire corridors have been turned into view-lot suburbs, wetland liquefaction zones into marinas, and floodplains into industrial districts and housing tracts.

Monolithic public works have been substituted for regional planning and a responsible land ethic.”

Let’s hope that the state of California can learn its lesson about how best to manage these fires — before another tragedy occurs.

ART OF THE DAY