Studies in the News Research Bureau, California State Library

November 28, 2018

To our readers: this issue is devoted to studies about .

The is the most destructive in California history, having killed more people than the previously three worst fires combined and destroyed more structures than the next seven worst fires combined. Smoke from the wildfire could have lasting public health effects. The “new abnormal” of regular mega-fires has a combination of causal factors, including the increased number of people living in the wildland-urban interface near forests, grasslands and scrublands (which tend to be fire hazard severity zones). Increased development offers not only more fuel, but also more potential ignition from downed power lines and accidental, negligent or intentional human actions, which account for 84 percent to 90 percent of wildfires in America. Nevertheless, Californians will return to fire-ravaged communities despite volatile rent and home prices, mortgage delinquencies, construction labor shortages, and the “parade of flippers.” More than 2 million California homes, or 15 percent of total households, are identified as at wildfire risk, and property insurance companies are reacting by refusing to renew policies or raising premiums. Meanwhile, federal and state fire suppression costs continue to climb.

Contents this week:

CULTURE & DEMOGRAPHY Poor, elderly, disabled and non-English-speaking more vulnerable to wildfire

ECONOMY RAND: Wildfire size in Sierra foothills to double by 2050, insurance market reacts Homebuyers’ fears of wildfire risk fade, real estate prices rebound within 1-2 years

ENVIRONMENT Climate change could increase wildfires, infections, fishery closures, crop failures in CA New activity model predicts levels of air pollution from prescribed burns Wildfires, controlled burns have differing levels of particulate matter ‘Prescribed burning may be an effective method to reduce fine particle emissions’

GENERAL GOVERNMENT More housing development near wildland vegetation increases wildfire risk in California Wildfire management must be strategically targeted, should include land-use regulations Immediate disaster management responses often inefficient, wrong for long-term Logging ineffective in preventing wildfires Fuel treatment helped reduce 2013 Rim Fire severity, but weather was stronger determinant

HEALTH 2015 wildfire smoke exposure in Northern CA linked to higher rates of ER visits 82 million in western U.S. will suffer health consequences from wildfire smoke in next 20 years

CULTURE & DEMOGRAPHY

“The unequal vulnerability of communities of color to wildfire.” By Ian Davies, et al. PLOS One, vol. 13, no. 11 (Nov. 2, 2018). 15 p. https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0205825

“[M]ost Americans living in areas at the highest risk from wildfires are affluent, sometimes owning second homes in the wildland-urban interface, or WUI. But these aren’t necessarily the most wildfire vulnerable Americans. Roughly 40 percent of Americans living in wildfire-prone areas, or about 12 million people, lack the resources to prepare for or recover from fire. In general, the study found that the elderly, disabled and non-English-speaking are more likely to be devastated by a fire. One reason is that cheaper housing, such as mobile homes or apartments, is often less durable during fires, and poorer Americans are less likely to have reliable transportation during an emergency. After a burn, renters don’t qualify for as much federal assistance as property owners. As well, the researchers point out that in the aftermath of the 2017’s Sonoma County fires in California, rental prices shot up, hurting lower income residents.” (High Country News, Nov. 21, 2018)

ECONOMY

The Impact of Changing Wildfire Risk on California’s Residential Insurance Market. By Lloyd Dixon, et al. RAND. Aug. 2018. 105 p. http://www.climateassessment.ca.gov/techreports/docs/20180827-Forests_CCCA4-CNRA-2018-008.pdf

“Yet the worst is probably still to come for much of the state. The California fire season usually ends with the first rains of fall.… Climate change appears likely to push the rains to even later in the year. Insurance companies in particular have started to fear the worst. A recent RAND study found that home-insurance premiums have risen in the state’s most fire-prone areas compared with its less fire-prone areas. Some high-risk homeowners have switched to higher-deductible policies. The same study estimated that as the climate changes, the number of acres burned annually in the Sierra foothills will double in the next 30 years. If humans continue emitting carbon pollution at current rates, the number of acres burned will quadruple by 2100.” (The Atlantic, Nov. 11, 2018)

“Wildfire risk, salience & housing demand.” By Shawn McCoy, et al. Journal of Environmental Economics and Management, vol. 91 (Sep. 2018). 45 p. https://www.sciencedirect.com/science/article/abs/pii/S0095069617305181?via%3Dihub (Available from the California Research Bureau)

“The study affirms that the [wildland-urban interface fire risk] problem may get worse before it gets better, partly because wildfire risks don’t impact property values in fire-prone areas over the long run.… [I]f individual home buyers keep making high-risk decisions, and if wildfires continue to grow more frequent and intense, more energy will focus on stronger public policies for mitigating risks and avoiding costs for the general public..… In flood prone inland areas, for example, public policy has begun to focus on buying out properties in areas of chronic flooding, and prohibiting new construction in those areas. Coastal areas impacted by rising sea levels are also beginning to show signs of desertion and long term, significant property value loss.… [However] a similar dynamic may not deter homeowners in fire prone areas, partly because flood risks are to some extent more knowable.” (Inman News, Sep. 4, 2018, reposted at WFG National Title Insurance Company)

ENVIRONMENT

Fourth National Climate Assessment (NCA4), Volume II: Impacts, Risks, and Adaptation in the United States. By U.S. Global Change Research Program. National Oceanic and Atmospheric Administration. Nov. 23, 2018. Report-in-brief: 196 p. Summary and downloads: https://nca2018.globalchange.gov/ Southwest region chapter: https://nca2018.globalchange.gov/chapter/25/

“California and the West have already witnessed an expansion of catastrophic blazes due to climate change and rising warming, with twice as much acreage burned by wildfire than would have occurred otherwise. ‘Higher temperatures sharply increase the risk of megadroughts – dry periods lasting 10 years or more,’ says the report.… Such ‘megadroughts’ will trigger a cascade of impacts, including tripling the frequency of large wildfires – those roughly 20 square miles or larger – than what has historically occurred. Impacts could be lessened … if action was taken to sharply reduce greenhouse gas emissions.” (Sacramento Bee, Nov. 23, 2018)

From the Fourth National Climate Assessment, Volume II, Chapter 25:

“Forecasting the Impacts of Prescribed Fires for Dynamic Air Quality Management.” By M. Talat Odman, et al. Atmosphere, vol. 9 no. 6 (June 8, 2018). 20 p. https://www.mdpi.com/2073-4433/9/6/220

Prescribed burning (PB), where low-intensity fires are intentionally ignited and managed, is used throughout the United States to maintain the ecosystem and reduce wildfire risk. “However, PB emissions contribute significantly to trace gas and particulate matter loads in the atmosphere. In places where air quality is already stressed by other anthropogenic emissions, PB can lead to major health and environmental problems. We developed a PB impact forecasting system to facilitate the dynamic management of air quality by modulating PB activity. In our system, a new decision tree model predicts burn activity based on the weather forecast and historic burning patterns.” This report is one of a series in Atmosphere’s special issue, Fire and the Atmosphere.

“A Review of Community Smoke Exposure from Wildfire Compared to Prescribed Fire in the United States.” By Kathleen M. Navarro, et al. Atmosphere, vol. 9 no. 6 (June 8, 2018). 11 p. https://www.mdpi.com/2073-4433/9/5/185

“Sixteen studies that examined particulate matter exposure from smoke were identified for this synthesis—nine wildland fire studies and seven prescribed fire studies. PM2.5 [particulate matter less than 2.5 microns in diameter] concentrations from wildfire smoke were found to be significantly lower than reported PM2.5 concentrations from prescribed fire smoke. Wildfire studies focused on assessing air quality impacts to communities that were nearby fires and urban centers that were far from wildfires. However, the prescribed fire studies used air monitoring methods that focused on characterizing exposures and emissions directly from, and next to, the burns. This review highlights a need for a better understanding of wildfire smoke impact over the landscape. It is essential for properly assessing population exposure to smoke from different fire types.”

“Airborne measurements of western U.S. wildfire emissions: Comparison with prescribed burning and air quality implications.” By Xiaoxi Liu, et al. Journal of Geophysical Research: Atmospheres, vol. 122 no. 11 (June 16, 2017). 22 p. https://authors.library.caltech.edu/79079/1/Liu_et_al-2017-Journal_of_Geophysical_Research_ _Atmospheres.pdf

“This study reports an extensive set of emission factors (EFs) for over 80 gases and 5 components of submicron particulate matter (PM1) from [three] temperate wildfires. These include rarely, or never before, measured oxygenated volatile organic compounds and multifunctional organic nitrates.… The wildfires emitted high amounts of PM1 (with organic aerosol (OA) dominating the mass) with an average EF that is more than 2 times the EFs for prescribed fires … [and] our PM1 emission estimate … is over 3 times that of the NEI [National Emissions Inventory] PM2.5 estimate.… This study indicates that the source of OA from biomass burning in the western states is significantly underestimated. In addition, our results indicate that prescribed burning may be an effective method to reduce fine particle emissions.”

GENERAL GOVERNMENT

“Rapid growth of the US wildland-urban interface raises wildfire risk.” By Volker Radeloff, et al. Proceedings of the National Academy of Sciences, vol. 115 no. 13 (Mar. 27, 2018). 6 p. http://www.pnas.org/content/115/13/3314

“Between 1990 and 2010, an estimated 45 percent of all new housing units built in California were constructed in what experts refer to as the wildland-urban interface – where the state’s cul-de-sac’d suburban subdivisions and rural communities meet its flammable forests and shrub fields. The encroachment of homes into undeveloped areas creates a much larger and challenging front for firefighters to defend.… California already has among the strictest fire-minded regulations on construction.… But some of those regulations were written with a certain type of community in mind.… And while many existing regulations require new construction be ‘hardened’ to embers, they don’t apply to existing homes. That leaves many of California’s at-risk communities stuck with old, fire-prone homes and inadequate or constrained infrastructure.” (CALmatters, Nov. 19, 2018).

From (Nov. 15, 2018):

“Learning to coexist with wildfire.” By Max Moritz, et al. Nature, vol. 515 (Nov. 6, 2014). 9 p. https://www.nature.com/articles/nature13946 (Available from the California Research Bureau)

“The impacts of escalating wildfire in many regions – the lives and homes lost, the expense of suppression and the damage to ecosystem services – necessitate a more sustainable coexistence with wildfire. Climate change and continued development on fire-prone landscapes will only compound current problems. Emerging strategies for managing ecosystems and mitigating risks to human communities provide some hope, although greater recognition of their inherent variation and links is crucial. Without a more integrated framework, fire will never operate as a natural ecosystem process, and the impact on society will continue to grow. A more coordinated approach to risk management and land-use planning in these coupled systems is needed.”

“The dangers of disaster-driven responses to climate change.” By Sarah Anderson, et al. Nature Climate Change, vol. 8 (Aug. 2018). 3 p. Complimentary non-print access: https://www.nature.com/articles/s41558-018-0208-8.epdf ?author_access_token=o-OJoCZXBaaC3NHFvqyGI9RgN0jAjWel9jnR3ZoTv0NEYDogIzu DPWCNbGmQ7dxLdrjhlnBB4rQ-GzW9As05lm2ozMd-tijquba5PQVvO74dAlFV0W-BG3UEZ- kFmO7h48z8Zpfjf2cZROqrepsrKA%3D%3D DOI: https://doi.org/10.1038/s41558-018-0208-8

“But people and governments don’t always respond in ways that reduce the risk most effectively. For example, our research shows that they place fuels management projects close to places that have had recent wildfires. These are often places at reduced risk of wildfire relative to places that haven’t just had a wildfire. And our research shows that responses to wildfire and other natural hazards tend to reduce risks in the short rather than long term. Moreover, most responses to fire are focused on suppression and fuels management, rather than also emphasizing other policy responses.” (The Conversation, Nov. 11, 2018)

“Does increased forest protection correspond to higher fire severity in frequent-fire forests of the western United States?” By Curtis Bradley, et al. Ecosphere, vol. 7 issue 10 (Oct. 26, 2015). 13 p. https://esajournals.onlinelibrary.wiley.com/doi/full/10.1002/ecs2.1492

“A common assumption is that logging, or removing some trees, would prevent fires. In fact, many forest experts say that logging is ineffective. This is because the tree remnants left over after logging, such as stumps and branches, provide a super-fuel for fire – one that is even drier (and more flammable) in the absence of a forest canopy. There is plenty of science backing these claims. For instance, a recent study showed that burn severity tended to be higher in areas with higher levels of management. Scholars working on wildfire conservation have also rebuked arguments that logging protects endangered species from forest fires, a common argument in favour of tree removal.… Even post-fire logging is counterproductive and can lead to more fires.” (BBC News, Nov. 13, 2018)

Effect of fuels management, previous wildfire and fire weather on Rim Fire severity. By Jamie Lydersen, et al. California Fire Science Consortium. Nov. 13, 2017. Webinar: 56 min 29 sec. Presentation: 52 slides. Landing page, with webinar, slidedeck and further reading: http://www.cafiresci.org/events-webinars- source/category/effect-of-fuels-management-previous-wildfire-and-fire-weather-on-rim-fire-severity

“We assessed the relative influence of previous fuels treatments (including wildfire), fire weather, vegetation and water balance on Rim Fire severity.… Areas without recent fuels treatments and areas that previously burned at high severity tended to have a greater proportion of high severity fire in the Rim Fire. Areas treated with prescribed fire, especially when combined with thinning, had the lowest proportions of high severity. Proportion of the landscape burned at high severity was most strongly influenced by fire weather and proportional area previously treated for fuels or burned by low to moderate severity wildfire.… Our results show that fuels treatments and low to moderate severity wildfire can reduce fire severity in a subsequent wildfire, even when burning under fire growth conditions. These results serve as further evidence that both fuels treatments and lower severity wildfire can increase forest resilience.”

HEALTH

“Cardiovascular and Cerebrovascular Emergency Department Visits Associated with Wildfire Smoke Exposure in California in 2015.” By Zachary S. Wettstein, et al. Journal of the American Heart Association, vol. 7 no. 8 (Apr. 11, 2018). 35 p. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6015400/

“Research into the long-term health effects of large wildfires is still new.… An extensive study of the 2015 wildfire season in Northern California found that smoke exposure led to increased emergency room visits for adults of all ages, but particularly those over 65 years old. One of the biggest research projects on the subject, the study looked at nearly 1.2 million emergency room visits during the summer of 2015, and found that during smoke-dense periods, there was a statistically significant increase in emergency room visits for heart attack, stroke and respiratory infection.” (New York Times, Nov. 16, 2018)

“Particulate air pollution from wildfires in the Western US under climate change.” By Jia Coco Liu, et al. Climatic Change, vol. 138, issue 3-4 (Oct. 2016). 12 p. https://link.springer.com/article/10.1007/s10584-016-1762-6 (Available from the California Research Bureau) Smoke Wave County Map: https://khanotations.github.io/smoke-map/

“We create a new term ‘Smoke Wave,’ defined as ≥2 consecutive days with high wildfire-specific PM2.5, to describe episodes of high air pollution from wildfires. We develop an interactive map to demonstrate the counties likely to suffer from future high wildfire pollution events. For 2004-2009, on days exceeding regulatory PM2.5 standards, wildfires contributed an average of 71.3% of total PM2.5. Under future climate change, we estimate that more than 82 million individuals will experience a 57% and 31% increase in the frequency and intensity, respectively, of Smoke Waves. Northern California, Western Oregon and the Great Plains.”

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