We Can’t Stop the Wildfires—But We Can Stop the Disaster (#243)

Summary

Episode Summary: "We Can’t Stop the Wildfires—But We Can Stop the Disaster" (#243)

Host: Lynn Thoman
Guest: Jack Cohn, Fire Expert, Firefighter, and U.S. Forest Service Fire Scientist
Release Date: April 1, 2025

In this enlightening episode of 3 Takeaways, host Lynn Thoman engages in a profound discussion with Jack Cohn, a seasoned fire expert who has significantly contributed to wildfire management and prevention strategies. The conversation delves into the escalating issue of wildfires, exploring their causes, evolution over time, and effective strategies to mitigate their devastating impact on communities.

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1. Understanding the Major Causes of Wildfires

Jack Cohn begins by addressing the primary ignition sources of wildfires. He emphasizes the significant role humans play in igniting wildfires:

Jack Cohn [02:26]: "Most wildfires are ignited by humans, but that's nothing new. Wildland fires have mostly been started by humans in North America for thousands of years."

He highlights contemporary human activities responsible for ignitions, including power lines, railroads, burning debris, and fireworks. Despite natural causes like lightning, the predominant factor remains anthropogenic.

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2. Evolution of Wildfires in the 20th and 21st Centuries

The discussion transitions to how wildfires have transformed over the past century. Cohn introduces the concept of the Wildfire Paradox, explaining how human efforts to control wildfires have inadvertently intensified them:

Jack Cohn [02:50]: "Wildfires have always been a part of the landscape, but what's changed over particularly the last hundred years is our increasing attempt to control wildfires."

Cohn outlines that while suppression efforts have been largely effective in reducing the number of wildfires, they have led to the accumulation of wildland vegetation. This buildup results in more severe and intense wildfires when they do occur, especially under strong winds and dry conditions.

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3. Wildland vs. Urban Fire Management

Lynn Thoman probes into whether the devastation of recent fires, such as those in Los Angeles, stems from wildland fire management or urban fire management failures.

Jack Cohn [04:19]: "The urban and suburban wildfire problem is how fires ignite and spread within residential areas."

Cohn distinguishes between wildland fires and those that threaten urban communities. He asserts that while extreme wildfires may be inevitable, the catastrophic destruction of communities can be significantly reduced by focusing on how fires ignite and spread within residential zones.

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4. Mechanisms of Fire Spread in Communities

Addressing a common misconception, Cohn clarifies that wildfires do not spread as "walls of flames" engulfing neighborhoods. Instead, the primary mode of fire propagation in urban areas is through burning embers carried by the wind:

Jack Cohn [05:12]: "Much of the fire spread in residential areas is from burning embers carried by the wind."

These embers can ignite homes directly or accumulate flammable materials around structures, leading to multiple simultaneous ignitions. Cohn emphasizes that the spread is driven by burning structures rather than the wildfire front itself.

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5. Limitations of Firefighting Resources

The conversation shifts to the efficacy of traditional firefighting methods in combating widespread community fires during extreme wildfire conditions.

Jack Cohn [06:10]: "Firefighters, more firefighting resources can't prevent disastrous community destruction during the extreme wildfire conditions."

Cohn explains that even substantial firefighting resources are often overwhelmed when hundreds of homes ignite simultaneously. He notes that in high-density areas, preventing neighborhood fires typically requires significant manpower and equipment—resources that become untenable during large-scale wildfires.

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6. Effective Home Ignition Risk Management Strategies

Turning to solutions, Cohn advocates for proactive measures to make communities more fire-resistant:

Jack Cohn [07:38]: "The key to preventing community destruction during extreme wildfires is to prevent homes from catching fire, not by attempting extreme wildfire control."

Key strategies include using ignition-resistant and non-combustible building materials for roofs and sidings and clearing away dead brush and vegetation around homes. These measures can significantly reduce the likelihood of homes igniting during wildfire events.

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7. Challenges with Implementing Fire-Resistant Zoning

Lynn Thoman raises the potential benefits of zoning laws that mandate the use of fire-resistant materials in rebuilding efforts, especially in fire-prone areas like Los Angeles.

Jack Cohn [08:34]: "Zoning is an incredibly controversial kind of action and so there is a definite resistance to new zoning and new codes. So to my knowledge, no."

Cohn indicates that despite the clear advantages, there is considerable resistance to implementing such zoning changes, hindering progress toward more fire-resilient communities.

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8. Final Insights and Three Takeaways

Before concluding, Cohn underscores the importance of community involvement in fire prevention:

Jack Cohn [09:08]: "Tell them we can't be effective without you."

He reiterates that while ignition-resistant homes are crucial, firefighting efforts remain essential for comprehensive community fire protection.

Cohn then presents his three key takeaways:

1. Current wildfire strategies are failing.

   • Evidence: Massive fires and destruction, particularly in Southern California.

2. Extreme wildfires are inevitable, but disastrous community destruction is not.

   • Mechanism: While wildfires initiate with burning embers, the subsequent community fires are driven by urban-specific factors.

3. The best defense is fire-resistant communities.

   • Strategy: Focus on making homes and their immediate surroundings fire-resistant rather than solely relying on wildfire suppression.

Jack Cohn [09:59]: "We can prevent catastrophic community destruction without controlling the uncontrollable wildfires. That's by focusing on fire resistant communities, not wildfire suppression."

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Conclusion

In this episode, Jack Cohn provides a compelling analysis of the wildfire crisis, highlighting the limitations of traditional wildfire management and the imperative shift toward building fire-resistant communities. His insights stress that while we may not be able to halt wildfires entirely, strategic community planning and resilient infrastructure can significantly mitigate their destructive impact.

For listeners seeking to understand the complexities of wildfire management and to learn actionable strategies for community protection, this episode offers invaluable perspectives grounded in expertise and real-world experience.

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Listen to the full episode here and subscribe to the Three Takeaways newsletter for more insightful discussions.

Transcript

[Lynne Thoman]

Wildfires are no longer just a seasonal occurrence. They've become an uncontrollable force. From the massive infernos ravaging California to raging blazes in far flung corners of the earth, the scale of destruction is staggering. Entire communities wiped out, homes reduced to ash, lives forever changed. What was once seen as a natural part of the ecosystem now feels like an unstoppable disaster. So the question is, are we truly powerless against this growing threat? Or is there a way for us to fight back? Hi everyone, I'm Lynne Thoman and this is three Takeaways. On three Takeaways, I talk with some of the world's best thinkers, business leaders, writers, politicians, newsmakers and scientists. Each episode ends with three key takeaways to help us understand the world, and maybe even ourselves, a little better. Today I'm excited to be joined by Jack Cohn, a fire expert with a unique perspective both as a firefighter and a U.S. forest Service fire scientist. Jack co developed the National Fire Danger Rating System and has spent years fighting and studying fires, transforming our understanding of them. His groundbreaking work on how homes ignite and fires spread is reshaping fire management. Today we'll tackle an important Is the destruction we've witnessed inevitable or can we do more to protect ourselves? Let's dive in and rethink how we approach fire. Welcome Jack, and thank you so much for joining three Takeaways today.

[Jack Cohn]

Oh, thank you, Lynn, very much for being interested in the topic.

[Lynne Thoman]

It's such a critical topic today. Jack, can you explain briefly the major causes of wildfires? Is it lightning or is it man made causes such as sparks from power lines, or is it else?

[Jack Cohn]

Most wildfires are ignited by humans, but that's nothing new. Wildland fires have mostly been started by humans in North America for thousands of years, so today they're often caused by power lines, railroads, burning debris, and fireworks. Regardless of the cause, however, wildfires are inevitable.

[Lynne Thoman]

Have wildfires changed in the 20th and 21st centuries? Are they different now than they used to be?

[Jack Cohn]

Wildfires have always been a part of the landscape, but what's changed over particularly the last hundred years is our increasing attempt to control wildfires. Over this period, we have successfully suppressed 95 to 98% of wildfires, keeping the area burned small. While this may seem like a good thing, it actually just postpones fires to inevitably burn during more severe conditions. When we suppress fires, wildland vegetation continues to grow and regenerate, and this results in fuel conditions that can produce more intense wildfires during strong winds and dry conditions. That's called the wildfire paradox. That is, the more we try to stop fires, the worse they become when they inevitably occur. So we need to find ways of increasing wildland fires instead of limiting them.

[Lynne Thoman]

And when you look at the massive devastation of recent fires, such as those in LA and elsewhere, is the problem wildland fire management or is it urban fire management and the ways the fires spread in urban areas, we need to.

[Jack Cohn]

Distinguish fires in wildlands are a separate issue from fires in urban communities. The urban and suburban wildfire problem is how fires ignite and spread within residential areas. Most of the disastrous community fire destruction occurs after the wildfire has ceased near the community. While we can't stop extreme wildfires, we can significantly reduce community wildfire risk. The key to preventing disastrous fire destruction in high density residential areas is by addressing how community ignition and fire spread occurs during the extreme wildfire conditions.

[Lynne Thoman]

So how do fires spread in communities? Do they spread like a wall of flames that engulfs a whole neighborhood?

[Jack Cohn]

Not at all. The media often portrays wildfires as huge unstoppable flaming tsunamis or walls of but that's not how the fires actually spread in urban areas. In fact, much of the fire spread in residential areas is from burning embers carried by the wind. Initially, these embers may travel long distances from a wildfire, accumulating on homes to ignite them or directly by igniting flammable materials around the homes. When the wind is strong, burning embers can land across a wide area and simultaneously ignite numerous homes. But the disastrous community fire spread continues from burning structures, not from the extreme.

[Lynne Thoman]

Wildfire is the most effective way then to fight fires. More firefighting resources, more fire engines and.

[Jack Cohn]

Firefighters, more firefighting resources can't prevent disastrous community destruction during the extreme wildfire conditions. Wildfire suppression and community fire protection that's with aircraft and fire engines becomes ineffective during extreme fire conditions. Even in Southern California, with hundreds of fire engines and firefighters, they are overwhelmed by hundreds of small fires simultaneously igniting and leading to hundreds of burning homes scattered across a community. In high density residential communities, it takes a minimum of three fire engines and 15 firefighters during average fire conditions to prevent one house fire from spreading to its neighbors. So when hundreds to thousands of ignition vulnerable homes are at risk, it's impossible to prevent the community fire disaster. Creating ignition and fire resistant communities is the only way we can prevent disastrous community fire destruction.

[Lynne Thoman]

The home ignition risk management strategies that you believe are the most effective are flame resistant materials for roofs and for sidings and the clearing away of dead brush and plants away from Homes, is that right?

[Jack Cohn]

Exactly. The key to preventing community destruction during extreme wildfires is to prevent homes from catching fire, not by attempting extreme wildfire control. There are readily available ignition resistant and non combustible home building materials and designs, along with the mitigation of flammable materials immediately surrounding homes that can make the difference between community survival and destruction.

[Lynne Thoman]

It would seem that changes to zoning requiring rebuilding with fire resistant materials would be beneficial to communities, especially communities like LA that have been devastated by fires. To your knowledge, is LA implementing new zoning requirements of flame resistant materials?

[Jack Cohn]

I'm not aware that they have made the decision one way or the other with regard to rebuilding, but zoning is an incredibly controversial kind of action and so there is a definite resistance to new zoning and new codes. So to my knowledge, no.

[Lynne Thoman]

That is astonishing. Jack, is there anything else you'd like to add before I ask for the three takeaways you'd like to leave the audience with today?

[Jack Cohn]

Yes. When I speak with fire chiefs, they often ask me what should I tell homeowners? And I say to them, well, tell them we can't be effective without you. It sounds simple, but the reality is urban firefighting efforts cannot be effective during extreme wildfire conditions without ignition resistant homes. But ignition resistant is not fireproof. Most ignitions will be eliminated with ignition resistance, but some ignitions should be expected, and that means firefighters will remain essential for community fire protection.

[Lynne Thoman]

Jack, what are the three takeaways you'd like to leave the audience with today?

[Jack Cohn]

Takeaway 1 Current wildfire strategies are failing. That's evidenced by massive fires and destruction, most recently in Southern California. My second takeaway is extreme wildfires are inevitable but disastrous. Community destruction is not. Wildfires initiate community ignitions with burning embers, but then communities burn as urban fires, not as wildfires. This means preventing disasters isn't about stopping wildfires, it's about reducing home ignition and community fire spread. My third takeaway is the best defense is fire resistant communities. The most effective wildfire risk reduction happens within the communities, not in surrounding forests and wildlands. Fire resistant homes and surroundings prevent most of ignitions that occur during extreme wildfires. And I have a bottom line. We can prevent catastrophic community destruction without controlling the uncontrollable wildfires. That's by focusing on fire resistant communities, not wildfire suppression.

[Lynne Thoman]

Jack, thank you. Thank you for all your work fighting fires and mitigating damage to homes and communities.

[Jack Cohn]

Thank you very much. And thank you very much for your interest.

[Lynne Thoman]

Absolutely. It's such a critical issue now and people just don't understand it correctly. If you're enjoying the podcast, and I really hope you are, please review us on Apple Podcasts or Spotify or wherever you get your podcasts. It really helps get the word out. If you're interested, you can also sign up for the Three Takeaways newsletter at 3takeaways.com, where you can also listen to previous episodes. You can also follow us on LinkedIn, X Instagram, and Facebook. I'm Lynn Thoman, and this is three Takeaways. Thanks for listening.