Fire Narratives: Are Any Accurate?

We may not know as much as we think we know about wildfires in the Wildland-Urban Interface

This article by Sarah McCaffrey, a Research Forester with the U.S. Forest Service, first appeared at Fire Adapted Communities Learning Network.


How you tell a story influences what conclusions people draw from it (think Aesop’s Fables). Over the past decade, the overarching American wildfire narrative has become fairly focused on three dynamics: fuels buildup due to suppression, climate change, and the expanding wildland-urban interface (WUI). But what are these narratives based on?

There is a fair bit of research and debate as to when and where fuel overloading and climate change will have the most influence, in fact too much to be easily citable here. However, according to research for a paper that I’m developing with Matt Thompson of the Rocky Mountain Research Station and Courtney Schultz of Colorado State University, few data support the WUI story. Specifically, only limited data support the arguments for why and how the WUI is contributing to the wildfire problem.

For instance, a commonly cited concern is that 50–95 percent of wildfire suppression costs can be attributed to the protection of private property in the WUI. However, when our team followed the citations for this statement, we found that they all led back to data from a single 2006 Office of Inspector General (OIG) report (PDF, 1.57 MB). Further, the report reached that particular conclusion using data that most social scientists would find problematic at best. Stay tuned for my team’s paper to learn more about that report’s limitations.* We have found a few studies that examine the breakdown of suppression costs in a more rigorous manner, using meaningful metrics (e.g., the number of homes near the fire perimeter and the percent of private land). But, while they do find a positive association between homes being located in the WUI and suppression costs, none demonstrate causality or conclude that the costs of protecting private property come close to the low end of OIG’s estimates. Nor can we find any study that tracks changes in the WUI with changes in suppression costs over time, even though a key perceived “problem” with the WUI is that its expansion will automatically increase wildfire suppression costs.

Similarly, although it is often stated that wildfire-related housing loss is increasing, it is hard to find any data that support or deny this claim, as wildfire-related housing loss hasn’t been tracked consistently until fairly recently. Further, even the existing data are problematic. For instance, the National Interagency Coordination Center (NICC) claims that 2,638 homes were lost nationally in 2015 (see page 9 of this NICC report, PDF, 830 KB); while CAL FIRE reports that 3,217 homes were destroyed in California alone that same year (see page 10 of this CAL FIRE report, PDF, 1.28 MB). Further, while it is too short of a time span to draw any solid conclusions, it is worth noting that both datasets suggest that higher losses are periodic and due to specific wildfire events. For example, the graph below, which I developed using NICC annual summary reports, illustrates that when excluding the state that lost the most residences in a given year — say Tennessee in 2016, the year of the Gatlinburg fires — home loss (shown in green) is relatively flat.

wildfire structure loss

Inaccurate Stories Are Unlikely to Lead to Effective Solutions
Accepting WUI narratives that lack sufficient supporting data can lead to developing solutions that are less likely to have the desired impact, because they may be targeting the wrong problem. Further, these proposed solutions may have unintended consequences because they don’t take existing data, or lack thereof, or the larger context into account. For instance, a common recommendation based on the WUI narrative is to limit development in fire-prone areas. However, while we do have fairly robust science concerning factors that make an individual home more fire resistant, we don’t have much information on what type of larger scale development is associated with improved wildfire outcomes. There are only a few relevant studies, and they offer conflicting “solutions.” For example, some studies suggest clustered housing would help with decreasing suppression costs, but others suggest clustered housing would lead to more losses.

Another common recommendation based on the WUI narrative is to form a national fire-insurance program similar to the National Flood Insurance Program, which appears to be seen as a means of ensuring that WUI residents bear the cost of living there. This recommendation ignores the significant evidence concluding that the National Flood Insurance Program has done little to shift the cost burden from federal taxpayers (and in fact has probably increased it) or to limit housing development in flood-prone areas. This argument also seems to assume that if individuals can’t obtain or afford insurance, then they will choose to not live in the WUI. However, there is no evidence that this is the case. It’s just as likely that individuals will continue to live there for a variety of reasons (e.g., amenities, affordability in other regards) and just take their chances, essentially making those with fewer resources even more vulnerable.

Further, insurance levers can raise an equity consideration: if insurance did have the desired effect, it is likely that only the wealthy would be able to live in the WUI since only they could afford to pay higher insurance premiums or to self-insure. It is worth asking whether that is an acceptable tradeoff.

Shifting Our Language
Through this process, I have begun to question whether the WUI is still a useful construct. While it may have been useful at one point to draw attention to the increasing intermingling of housing and natural vegetation, it now seems to create an artificial distinction that may be misleading. I doubt many of those who lost their homes in the recent California wildfires, particularly in Santa Rosa, thought of themselves as living in the WUI. Further, a preliminary analysis by the University of Wisconsin shows that regarding the Tubbs Fire, many of the losses were not technically in the WUI. Instead, the largest portions of homes lost were in areas considered either too dense or not dense enough to be classified as the WUI. Forest Schafer’s recent blog post about how Lake Tahoe partners are rethinking their WUI is another example of the limitations of drawing artificial lines when assessing wildfire risk.

And then there is the question of how limiting development in the WUI would work. Beyond equity issues and the fact that we don’t have strong evidence regarding what “better” land-use planning for wildfire looks like, I always wonder, “So, where are people supposed to live then?” As one recent newspaper headline stated: “All Californians Live in Fire Country Now.” Perhaps just thinking about how we can best live in fire-prone landscapes may be a more useful way to frame the discussion, rather than creating artificial distinctions based on housing density and natural vegetation.

*This blog describes initial findings from a paper that Courtney, Matt and I are working on. The articles referenced in this blog post will be identified in that paper, which will be available on Treesearch once it is published.

Sarah McCaffrey
Photo credit: Sarah McCaffrey

Sarah McCaffrey, Ph.D., is a research forester for the USDA Forest Service, Rocky Mountain Research Station. Her research focuses on the social aspects of fire management. This work has included projects examining wildfire risk perception, social acceptability of prescribed fire and thinning, characteristics of effective communication programs, and incentives for the creation and maintenance of defensible space. She has also initiated work examining social issues that occur during and after wildfires, including evacuation-decision making, agency-community interactions during fires, public perception of wildfire management overall, views on the Cohesive Strategy, and perceptions about what it means to be a fire adapted community. She received her Ph.D. in Wildland Resource Science in 2002 from the University of California at Berkeley.

Is a little pre-fire mitigation around structures better than none?

According to experience from Colorado’s Fourmile Canyon Fire, sometimes the answer is “No”.

When Dave Lasky was leading the effort in the Four Mile Fire Protection District not far from Boulder, Colorado conducting pre-fire mitigation near structures, he and others assumed that doing SOMETHING, cutting trees and building slash piles, would be better than doing nothing. They realized it would not be the total solution in the wildland-urban interface (WUI), but when the Fourmile Canyon Fire started on September 2, 2010 the Fire Protection District found out how wrong they were.

Fourmile fire_map_MODIS_0418_9-8-2010
Map of the Fourmile fire near Boulder, showing heat detected by the MODIS satellite at 4:18 a.m. Sept. 8, 2010. Map by Wildfire Today and NASA.

After the ashes cooled, Dr. Jack Cohen, a U.S. Forest Service fire researcher who has investigated the effects on structures at numerous WUI fires, found what he has seen many times before (more details here). Most of the damaged homes, 83 percent in this case, ignited from airborne fire embers or surface fire spreading to contact the structure; not from high intensity crown fire or direct flame impingement.

The fuel reduction along travel corridors may have helped residents to evacuate, but the unburned slash piles, Mr. Lasky said, could have been a problem:

 In several areas, our crew’s piles were associated with complete stand mortality. We created ladders into the canopy. At best, these unburned piles represented a sad waste of money, and at worst, it is possible that if we hadn’t treated them, these stands might not have carried fire.

Below are excerpts from an article written by Mr. Lasky about what he learned. It first appeared at the website for Fire Adapted Communities Learning Network.


“Doing something is not better than doing nothing.
When the mitigation crew approached residents in the past, they often said, “I didn’t move up here to see my neighbors. I don’t want to cut trees.” In an effort to build momentum, we often performed work that we knew was not reflective of the best science, cutting fewer trees than we should have. This practice was in regard to both defensible space as well as shaded fuel-break projects. The hope was that as communities adjusted to the cosmetic changes, we’d be able to reenter and accomplish more.

“I still hear many colleagues say “let’s just get something done.” I believe this is wrong. We need to do it right or not do it at all. Half measures are proven to fail and engaging in them has great reputational costs. In the current climate of high-profile, catastrophic fires, I am not interested in fear mongering. But I am interested in applying our limited resources to only those communities that are fully committed.

“It’s not just about cutting trees in the wildland-urban interface.
Fuels crews are run by firefighters. Perhaps they should be run by architects. In retrospect, we spent far too much money on fuels reduction and not enough on assisting residents with the installation of fire-resistant building materials and landscaping. Few of the homes lost were directly impacted by crown fire; rather, embers undoubtedly ignited the fine fuels around them, which eventually led to the loss of entire structures. In many instances, residents would have been better served by our crew putting a decorative stone perimeter around the structure. Many residents are capable of cleaning gutters, but less can move tons of gravel. We had chainsaws, and we knew how to use them. We should have picked up our shovels instead.”

60 minutes: “Wildfires on the Rise”

Above: One of the homes that survived the Eiler Fire in northern California, August, 2014. Photo by Bill Gabbert.

The CBS TV show 60 Minutes recently aired a story titled, “Wildfires on the rise due to drought and climate change“, concentrating on how to deal with the increasing number of wildfires, and particularly what homeowners can do to protect their investments.

Below is an excerpt from the transcript:

Events like [the Yarnell Hill Fire that killed 19 member of the Granite Mountain Hotshots] add urgency to the work at a U.S. Forest Service lab. In this building in Missoula, Montana, scientists study how fires spread.

And one of them, Jack Cohen, made a specialty of how to better defend homes.

Jack Cohen: Clearly we’re not gonna solve the problem by telling people they’re gonna have to move their houses into a city from being out in the woods.

Steve Inskeep: Not gonna happen.

Jack Cohen: Right? It’s not gonna happen for a whole bunch of reasons, one of which is that the population who live there, including me– aren’t gonna do it.

Steve Inskeep: Is it reasonable for a homeowner in that situation, a fire bearing down on their neighborhood to just say, “Look, I pay my taxes. There are firefighters, there’s a fire department. The forest service, if it’s public land, has thousands of firefighters. It’s their job; put it out?”

Jack Cohen: So what if they can’t? Then the question becomes one of, “Well, if the extreme wildfires are inevitable does that mean that wildland-urban fire disasters are inevitable?” And my answer to that is no.

Adaptive resilience to wildfire

Above: Eiler Fire, northern California, August 6, 2014. Photo by Bill Gabbert.

As the climate shifts and fires become larger, more resistant to control, and occur over longer fire seasons, protecting private property and adapting to a new paradigm can become more challenging.

A recently published paper written by 12 authors has some insights to the issue that are rarely seen. The title is Adapt to more wildfire in western North American forests as climate changes.   The entire 2.7mb paper can be downloaded here.

Below are some excerpts.

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….In delivering this message, we focus specifically on the distinction between specified, adaptive, and transformative resilience (15, 16). Rigorous definition and critical assessment of resilience to wildfire are needed to develop effective policy and management approaches in the context of climate change. We suggest an approach based on the concept of adaptive resilience, or adjusting to changing fire regimes (e.g., shifts in prevailing fire frequency, severity, and size) to reduce vulnerability and build resilience into social–ecological systems (SESs). Adaptive resilience to wildfire means recognizing the limited impact of past fuels management, acknowledging the important role of wildfire in maintaining many ecosystems and ecosystem services, and embracing new strategies to help human communities live with fire. Our discussion focuses on western North American forests but is relevant to fire-influenced ecosystems across the globe. We emphasize that long-term solutions must integrate relevant natural and social science into policies that successfully foster adaptation to future wildfire.


Fire suppression, in addition to past logging and grazing and invasive species, has led to a build-up of fuels in some ecosystems, increasing their vulnerability to wildfire. For example, drier, historically open coniferous forests in the West (“dry forests”) have experienced gradual fuels build-up in response to decades of fire suppression and other land-use practices (8, 22, 23).

Historically, predominantly frequent, low-severity fires killed smaller, less fire-resistant trees and maintained low-density dry forests of larger, fire-resistant trees. Large, high-severity fires now threaten to convert denser, more structurally homogeneous dry forests to nonforest ecosystems, with attendant loss of ecosystem services (24). However, only forests in the Southwest show a clear trend of increasing fire severity over the last three decades, and only a quarter to a third of the area burned in the western United States experienced high severity during that time (25, 26). Although fuels build-up in dry forests can increase the area burned because of higher contagion, the 462% increase in the frequency of large fires in southwestern forests since the 1970s is also a result of an extension of the fire season by 3.6 mo [the average for the western United States is 2.8 mo (21)]. Overall, dry forests account for about half of the total forest burning in the western United States since 1984.


Management guided by specified resilience often values recent ecological and social dynamics, particularly when the goal is the conservation of particular species or landscapes. Such management is often informed by short temporal windows of HRV, or “recent HRV” (rHRV) (Fig. 3). This approach can be useful for responding to fires in the short term. However, when social and environmental conditions change rapidly, this approach may foster management goals that are unrealistic or unsustainable in the long run (48, 49).


Managing Fuels

Limiting Reliance on Fuels Treatments to Alter Regional Fire Trends. Managing forest fuels is often invoked in policy discussions as a means of minimizing the growing threat of wildfire to ecosystems and WUI communities across the West. However, the effectiveness of this approach at broad scales is limited. Mechanical fuels treatments on US federal lands over the last 15 y (2001–2015) totaled almost 7 million ha (Forests and Rangelands, https://www.forestsandrangelands.gov/), but the annual area burned has continued to set records.

Regionally, the area treated has little relationship to trends in the area burned, which is influenced primarily by patterns of drought and warming (2, 3, 20). Forested areas considerably exceed the area treated, so it is relatively rare that treatments encounter wildfire (73). For example, in agreement with other analyses (74), 10% of the total number of US Forest Service forest fuels treatments completed 2004–2013 in the western United States subsequently burned in the 2005–2014 period (Fig. 6). Therefore, roughly 1% of US Forest Service forest treatments experience wildfire each year, on average.

The effectiveness of forest treatments lasts about 10–20 y (75), suggesting that most treatments have little influence on wildfire. Implementing fuels treatments is challenging and costly (7, 13, 76, 77); funding for US Forest Service hazardous fuels treatments totaled $3.2 billion over the 2006–2015 period (6). Furthermore, forests account for only 40% of the area burned since 1984, with the majority of burning in grasslands and shrublands.

As a consequence of these factors, the prospects for forest fuels treatments to promote adaptive resilience to wildfire at broad scales, by regionally reducing trends in area burned or burn severity, are fairly limited.


Creating Fire-Adapted Communities.

The majority of home building on fire-prone lands occurs in large part because incentives are misaligned, where risks are taken by homeowners and communities but others bear much of the cost if things go wrong. Therefore, getting incentives right is essential, with negative financial consequences for land-management decisions that increase risk and positive financial rewards for decisions that reduce risk. For example, shifting more of the wildfire protection cost and responsibility from federal to state, local, and private jurisdictions would better align wildfire risk with responsibility and provide meaningful incentives to reduce fire hazards and vulnerability before wildfires occur.

Currently, much of the responsibility and financial burden for community protection from wildfire falls on public land-management agencies. This arrangement developed at a time when few residential communities were embedded in fire-prone areas. Land-management agencies cannot continue to protect vulnerable residential communities in a densifying and expanding WUI that faces more wildfire (12).

The US Government Accountability Office questioned the US Forest Service’s prioritizing protection of WUI communities that lie under private and state jurisdictions and has argued for increased financial responsibility for WUI wildfire risk by state and local governments (93). This shift in obligation would enhance adaptive governance and could increase the motivation to pursue adaptive resilience of WUI communities to increasing wildfire (94).


Key aspects of an adaptive resilience approach are:

  1. recognizing that fuels reduction cannot alter regional wildfire trends;
  2. targeting fuels reduction to increase adaptation by some ecosystems and residential communities to more frequent fire;
  3. actively managing more wild and prescribed fires with a range of severities; and
  4. incentivizing and planning residential development to withstand inevitable wildfire.

These strategies represent a shift in policy and management from restoring ecosystems based on historical baselines to adapting to changing fire regimes and from unsustainable defense of the wildland– urban interface to developing fire-adapted communities.


The authors of the paper are: Tania Schoennagel, Jennifer K. Balch, Hannah Brenkert-Smith, Philip E. Dennison, Brian J. Harvey, Meg A. Krawchuk, Nathan Mietkiewiczb, Penelope Morgan, Max A. Moritz, Ray Rasker, Monica G. Turner, and Cathy Whitlock.

Thanks and a tip of the hat go out to Ben.
Typos or errors, report them HERE.

NIST seeks help studying embers

The National Institute of Standards and Technology (NIST) is beginning a study to help determine how wildfires spread through a Wildland-Urban Interface (WUI). Many studies have found that structures are primarily ignited during a wildfire by burning embers that are lofted into the air and then land on or near buildings.

Without research, NIST says, building codes and standards do not provide adequate protection to structures within the WUI. More specifically, codes and standards do not adequately address the range of exposures during a WUI fire – especially firebrand or ember exposures.

Emberometer

NIST intends to develop a device which will help them learn more about burning embers. They are calling this instrument a “emberometer”. During the next two years, the researchers plan to fabricate and test an “emberometer” design developed for laboratory settings. Once initial testing is complete, a new design will be developed for an “emberometer” that can be used in controlled field experiments and actual WUI fire events (i.e., outside of the laboratory setting). Once fabrication for the “outdoor emberometer” is completed, NIST will identify field teams that can employ the instrument to collect exposure information on firebrands (embers) during field studies, and initial data collection to characterize firebrand (ember) exposure can begin.

How you can help

Fire photographers who have taken photographs of WUI fires with significant firebrand activity are encouraged to share their pictures and videos for analysis. If you are interested, contact Erica Kuligowski at erica.kuligowski@nist.gov or 301-975-2309 for guidelines.

President signs executive order to mitigate wildfire risks to Federal buildings

President Obama today signed an Executive Order on Wildland-Urban Interface Federal Risk Mitigation, intended to mitigate wildfire risks to Federal buildings located in the wildland-urban interface (WUI), reduce risks to people, and help minimize property loss to wildfire.

For new buildings and alterations to existing buildings greater than 5,000 square feet on Federal land within the WUI at moderate or greater risk to wildfire, the Executive Order directs Federal agencies to apply wildfire-resistant design provisions delineated in the 2015 edition of the International Wildland-Urban Interface Code promulgated by the International Code Council, or an equivalent code. These codes, which encompass the current understanding of wildfire hazard potential, will help increase safety and protect the lives of people who live or work in these buildings.