Wildfires, as their name denotes, are increasingly out of control, both physically and financially.
As of this writing, 28 “large active” wildfires were being fought in the U.S. alone, having burned more than 1.5 million acres and occupying more than 9,500 wildland firefighters, according to the National Interagency Fire Center. Since 2010, at least three years have seen 10 million U.S. acres burn.
Burned acreage isn’t necessarily increasing, but the loss per burned acre is. The year 2017 was a tipping point, when direct financial losses from wildfires spiked from roughly US$3B over the previous decade to more than US$19B, according to private reinsurance industry data.
Wildfire, combined with drought and heatwaves, has become the U.S.’s second-most-costly category of natural catastrophe in terms of insured loss.
This cost increase stems from a variety of factors. The character of ongoing development is a major factor. Continued development without consideration of wildfire hazard, or without designing in protection and defenses, puts homes and business in harm’s way. This trend mirrors coastline development amid increasing sea levels and resulting flood risk.
Another factor fueling wildfires is historical firefighting policy that, over most of the past 140 years, resulted in increased fuel loads in forests. Extinguishing fires as quickly as possible paradoxically preserves brush and trees for future combustion. Sometimes it’s better to let a fire burn naturally if it poses minimal risk.
Yet another complicating variable is any given fire’s likelihood of scaling. The overall wildfire hazard is driven by events too big and severe to readily extinguish. In fact, 1-2% of the fires burn 80-96% of the total affected area.
Finally, the changing climate, which has brought higher temperatures and longer drought to much of the country, is challenging the ability to control large, fast-moving fires.
How to Mitigate Wildfires’ Social and Economic Impact
Insurers are struggling to understand and underwrite the risks of affected properties. If losses continually outstrip premiums, insurers’ only options are to raise rates and deductibles or withdraw from providing coverage in what they may consider to be wildfire-prone areas. The lack of available and affordable insurance has secondary impact on the availability of mortgages and construction loans.
There’s only one way to manage the risk: hard, coordinated work on multiple fronts to better understand and address the hazard. Researchers and policymakers have successfully addressed other hard-to-predict hazards – like earthquakes, for example – on a global scale. A case in point is the Global Earthquake Model (GEM) Foundation. The wildfire community has the opportunity to follow and build upon the GEM example.
Informed by the GEM effort, here are four things that specifically need to happen to mitigate the social and economic impact of wildfires:
1. Better Characterize the Hazard
Although wildfire maps exist in different forms, they generally lack the detail that can help planners, developers and insurers assess and focus efforts needed to mitigate the risk. Effective wildfire mapping is complex. Event frequency and severity are correlated with both historical environmental conditions and short-term weather patterns.
The correlations are hardly linear. For example, wet seasons are less risky, but they foster growth of forest materials that may be dry the next year. Regional vegetation type is another risk variable: Brush regenerates within a few years, timber over a few decades; hence, past fires are not necessarily an indicator of future events.
A useful hazard map should also be based on considerations of the coupling with local weather patterns and both long- and shorter- term climate trends. This map would also integrate built and natural environments, since structures release about ten times more heat per unit area than forest materials. The most severe fires are ones that include both the forest and buildings.
The wildfire problem is complicated and represents a balance of development, changing weather trends, forest ecology, and tailored and optimized response, but the suite of predictive models can be better than it is today. Overall, the wildfire community needs to focus on better assessment of future wildfire frequency and even more so on severity. Within this framework, there needs to be a way of accommodating changes in the climate and development without frequent wholesale changes to maps.
2. Reduce Wildfire Consequences
Revisiting firefighting policy is needed in some regions. Although there is a natural tendency to attack every fire that arises, sometimes quickly extinguishing a fire means you’re preserving fuel that produces more severe fires in the future. Densely loaded fire materials allowed to thrive close to the forest floor are easily ignited and burn intensely. They serve as “ladder fuels” that promote upward flames, which spread to the canopy, or “crowns,” and lead to increased intensity and spread rate.
The current thinking has evolved to selectively allow fires to consume the fuel in their path and burn themselves out. Another option is conducting “prescribed” fires in at-risk areas, but extra care is needed to ensure that control is maintained. Thinning forests by hand works, but it is labor-intensive and expensive and thus limited in scale. Education and awareness are other effective measures given that humans trigger more than 80% of wildfires in the US. Both of these approaches have huge challenges to scale given the mass of accumulated forest fuels.
3. Reduce Social and Economic Vulnerability
A wealth of information already exists on how to protect built property from wildfires. The general approach is reducing combustibility with fire-resistant materials, sealing property to prevent intrusion by embers, clearing vegetation to create buffer zones between the forest and buildings, and implementing early warning systems.
Creating buffer zones, also known as defensive spaces, can be effective, but property owners may be prevented from clearing vegetation due to protections of trees desired for their greenhouse gas reduction potential, if not their beauty. A good solution is selecting fire-resistant vegetation.
Since many forest-adjacent communities are already built, efforts should prioritize areas of future development informed by best-in-class hazard maps and thoughtful building codes.
4. Mitigate Wildfire Consequences through Better Response and Recovery
Wildfires can burn for weeks despite manpower, water, foam and fire lines. Still, wildfires are ripe for innovation, and a wide array of novel firefighting techniques have been attempted, including explosives, jet engines and armies of firefighting drones, with no notable breakthroughs to date. In 2023, a four-year, US$11M global XPRIZE competition was launched to develop and demonstrate fully autonomous capabilities (e.g., robots) to detect and extinguish wildfires.
Though promising, autonomous technologies must still be guided by tools that define their optimal use. Advanced computing offers the potential to gather data from sensors and archives of past events and combine it with physics-based wildfire models and AI to generate future breakthroughs.
Path Forward
These wildfire mitigation measures require extensive effort, and the returns will likely seem merely incremental at first. But hard work pays off, and it’s very much worthwhile to assemble a global community of experts (from scientists to practitioners) under a common framework to develop new insights and tools.
GEM made good progress. Originated in 2009, it consists of leaders from government, academia and industry to address earthquake risk. The result has been a compilation of what is now considered the best available science in the forms of models, maps and tools for a range of applications from building codes to emergency response.
The effort against wildfires will need to be equally multifaceted. For wildfires, a consortium would need to:
- Synthesize the four approaches we’ve discussed above: wildfire characterization, reduction, defense and response.
- Advance, aggregate and integrate fundamental science (fire, atmosphere, forest ecology and others) and implement results in an accessible, open-source framework of tools fit for specific purposes.
- Fully apply available advanced computing, including proven artificial intelligence.
- Form a governance structure coordinating the needs of all stakeholders, including governments, academics, researchers, property owners and firefighting groups (the number of stakeholders for this problem is huge).
The consortium’s findings should be focused on reducing the hazard and its consequences, although it would significantly inform the decisions insurers, developers and financers make to accept any remaining wildfire risk. Insurance and finance are key players, but unlike other natural hazards, such as hurricanes and earthquakes for which largely satisfactory knowledge of the risk and suitable reduction measures exist, this is a problem that must balance the factors of the forest ecosystem that drive wildfire hazard with needs and desires of communities and industries. A purely financial solution shows no signs of being viable, so it’s time to think differently and join forces with a broader group of stakeholders to develop the knowledge and innovations needed to manage the wildfire hazard.
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