Managing Future Risk of Increasing Simultaneous Megafires

Our overall research goal is to understand current and future wildfire characteristics to support fire-related decisions throughout the 21st century in the face of resultant suppression resource scarcity and competition in the US. This project will model future patterns and uncertainty in the simultaneous co-occurrence of megafire events to inform risk management.  

 Research Questions:  

1. How will climate change alter future patterns of wildfire, particularly co-occurring megafires?  
2.  What implications does this hold for risk management decisions?    

We are developing statistical models to represent relationships between biogeophysical and human factors (e.g., ignitions, suppression policy, land and fuel management) and firefighting resource demand at geographical scales relevant to firefighting management decision-making. These resource demand and risk management models will be based on wildfire characteristics, climate, weather, and land history covariates. We are evaluating climate change impacts on ignition patterns and on wildfire risk with regional climate model projections from NA-CORDEX, and observations from the gridMET dataset, by looking at fire danger indices in concert with projected spatiotemporal patterns in anthropogenic activities associated with human-caused fires, as well as diagnostics for lightning activity.

Hypotheses: 

1. We hypothesize that ignition efficiency will increase further with warming, facilitating increased lightning-ignitions, and consequently increases in simultaneous wildfire events.  
2. We hypothesize that a positive feedback may occur where fire suppression resources at the national level become strained, reducing the efficacy of managing active fires and new ignitions, and further increasing resource strain and relative burned area.  
3. We hypothesize that short term fire management decisions (e.g., both fuel management and fire suppression) have significant delayed impacts, and demand innovative scientifically supported decision tools that explicitly account for climate change and the continuing interaction of natural and human systems.

Project Team

Alison Cullen, PI, Daniel J. Evans Endowed Professor of Environmental Policy, Evans School of Public Policy and Governance, University of Washington, Seattle WA. 

John Abatzoglou, Co-PI, Associate Professor, University of California Merced, Merced, CA. 

Melissa Bukovsky, Co-PI, Project Scientist III, National Center for Atmospheric Research, Boulder, CO. 

Sunniva Bloem, Research Assistant, PhD student, Evans School of Public Policy and Governance,  University of Washington, Seattle, WA. 

Brian Goldgeier, Research Assistant, Evans School of Public Policy and Governance,  University of Washington, Seattle, WA (MPA expected 2023). 

Reed Humphrey, Research Assistant, PhD student, Evans School of Public Policy and Governance,  University of Washington, Seattle, WA. 

Lee Kessenich, Associate Scientist I, National Center for Atmospheric Research, Boulder, CO. 

Seth McGinnis, Associate Scientist IV, National Center for Atmospheric Research, Boulder, CO. 

Linda Mearns, Senior Scientist, National Center for Atmospheric Research, Boulder, CO. 

Susan Prichard, Senior Research Scientist, School of Environmental and Forest Sciences, University of Washington, Seattle, WA. 

Haley Skinner, Research Assistant, Evans School of Public Policy and Governance, University of Washington, Seattle, WA (MPA expected 2023).

Ashwin Thomas, Research Assistant, PhD student, Environmental Systems,  University of California Merced, Merced, CA. 

Graduates

Harry Podschwit, Research Assistant, School of Environmental and Forestry Science, University of Washington, Seattle, WA (PhD, 2020). 

Alex Dolk, Research Assistant, Evans School of Public Policy and Governance,  University of Washington, Seattle, WA (MPA, 2021; MS, 2021). 

Marie Higinbotham, Research Assistant, Evans School of Public Policy and Governance,  University of Washington, Seattle, WA (MPA 2022). 

Emily Stephens, Evans School of Public Policy and Governance, University of Washington, Seattle, WA (MPA 2022).

Graduate Student Academic Defenses

Dolk, Alex. (MS/MPA 2021). Where There’s Fire, There’s Smoke: Examining Population Exposure to PM2.5 from Prescribed Burning in Northeastern Washington. Concurrent Master’s Thesis. Evans School of Public Policy and Governance, School of Environmental and Forest Sciences, University of Washington, Seattle, WA.

Podschwit, Harry. (PhD, 2021). Accounting for model uncertainties in statistical forecasts of wildfire parameters. Doctoral Dissertation. School of Environmental And Forest Sciences, University of Washington, Seattle, WA.

Stephens, Emily. (MPA, 2022). Winner of the Environmental Policy & Management Research Prize, All Lands, All Plans: Regional and Forest-Level Planning and Coordination in Eastern Washington Forests. Masters Degree Capstone, Evans School of Public Policy and Governance, University of Washington.

Higinbotham, Marie (MPA 2022). Incorporating Equity into Capital Planning and Decision-Making. Masters Degree Capstone. Evans School of Public Policy and Governance, University of Washington, Seattle, WA.

Conference Presentations

“Projected Changes in Inter-Regional Simultaneity of Megafires in the Western US Based on NA-CORDEX Regional Climate Simulations” (Seth McGinnis, Lee Kessenich, Linda Mearns, Melissa S Bukovsky, Alison Cullen). AMS Annual Meeting, Denver, CO. January 2023.

“Co-producing Actionable Climate Science for Wildland Fire Operations and Policy.” (Lee Kessenich, Melissa Bukovsky, Seth McGinnis, Linda Mearns, Alison Cullen, John Abatzoglou). AMS Annual Meeting, Denver, CO. January 2023.

“Projected Changes in Inter-Regional Simultaneity of Megafires in the Western US Based on NA-CORDEX Regional Climate Simulations” (Seth McGinnis, Lee Kessenich, Linda Mearns, Melissa S Bukovsky, Alison Cullen). AGU Fall Meeting, Chicago IL. December 2022.

“A Multi-Index Examination of Future Fire Season Length and Severity Over the United States.” (Melissa S Bukovsky, Lee Kessenich, Seth McGinnis, Linda Mearns, John Abatzoglou, Alison Cullen). AGU Fall Meeting, Chicago, IL. 16 Dec 2022.

“International Cooperation for Managing Wildfire Risk” (Sunniva Bloem, Alison Cullen, Linda Mearns, John Abatzoglou), Society for Risk Analysis, Annual Meeting, Tampa FL, December 2022.

“Fire Weather Forecasting in the Pacific Northwest” (Reed Humphrey, John Saltenberger, John Abatzoglou, Seth McGinnis, Alison Cullen) Society for Risk Analysis, Annual Meeting, Tampa FL, December 2022.

“Risk Management through Megafire Response” (Alison Cullen, Erin Belval, Haley Skinner, Brian Goldgeier, Sunniva Bloem, John Abatzoglou), Society for Risk Analysis, Annual Meeting, Tampa FL, December 2022.

“Growing Convergence Research: Co-producing Climate Projection Information for Managing Risk from Simultaneous Wildfires” (Alison Cullen, Reed Humphrey, Lee Kessenich, Seth McGinnis, John Abatzoglou), Society for Risk Analysis, Annual Meeting, Tampa FL, December 2022.

“Drivers of lightning-ignition efficiency in California forests.” (Ashwin Thomas). 2022 Yosemite Hydroclimate Meeting, Yosemite National Park. October 13, 2022.

“Taming fire: panel on climate change and wildfires” (Don Hankins, Susan Prichard) Aspen Ideas Festival, Aspen, CO. June 29, 2022.

“Western wildfires – adapting to a future with more fire” (Susan Prichard) University of Washington Botanical Gardens Plenary, March 2, 2022. [online]

“Where there’s fire, there’s smoke: Examining Population Exposure to PM2.5 from Prescribed Burning in Northeastern Washington.” (Ernesto Alvarado, Alison Cullen, Alex Dolk). International Association of Wildland Fire & Climate Conference, Pasadena, CA. May 2022.

“Future changes in Simultaneous Megafire projected by NA-CORDEX” (Melissa Bukovsky) European Geophysical Union. Vienna. May 2022

“Drivers of lightning-ignition efficiency in California forests.” (Ashwin Thomas). International Association of Wildland Fire Conference: Fire & Climate 2022, Pasadena, CA. May 2022.

“Multimodel Uncertainty in Projected Changes of Simultaneous Megafires in the Great Basin Based on NA-CORDEX Regional Climate Simulations.” (Seth McGinnis, Lee Kessenich, Harry Podschwit, Linda Mearns, Melissa Bukovsky, and Alison Cullen). AGU Fall Meeting, New Orleans LA. December 2021.

“Managing Future Fire Risk – an NSF Growing Convergence Research Project.” (Alison Cullen). Society for Risk Analysis 2021 Annual Meeting. December 2021.

“The role of international resource sharing arrangements in wildfire risk management in the face of climate change.” (Sunniva Bloem). Society for Risk Analysis 2021 Annual Meeting. December 2021.

“Symposium: Managing and Reducing the Risk of wildfire through Response and Fuel Treatment.” (Alison Cullen). Society for Risk Analysis 2021 Annual Meeting. December 2021.

“Projected Effects of Climate Change on Simultaneous North American Megafires Based on NA-CORDEX Regional Climate Simulations.”  (Seth McGinnis, Harry Podschwit, Lee Kessenich, Linda Mearns, and Alison Cullen) GC081-07, 2020 Fall Meeting, American Geophysical Union, December 2020 https://agu.confex.com/agu/fm20/meetingapp.cgi/Paper/687152

“Managing Future Risk of Increasing Simultaneous Megafires” (Alison Cullen, Harry Podschwit, Linda Mearns, John Abatzoglou, Seth McGinnis, Melissa Bukovsky, Susan Prichard) Society for Risk Analysis 2020 Annual Meeting, December 2020.

Workshops

NSF Growing Convergence Research Managing Future Risk of Simultaneous Wildfire. Stakeholder Workshop. April 2021.

NSF Growing Convergence Research Managing Future Risk of Simultaneous Wildfire.” Stakeholder Workshop. June 2021.

Convergence Workshop on Simultaneous Fires, Stakeholder Focus Group, Association for Fire Ecology. November 2021.

Webinars, Seminars, and Podcasts

“Burning Issues: Wildfires” Podcast. (Alison Cullen). Burning Issues. University of Chicago. June 2022.

“Western wildfires – adapting to a future with more fire.” (Susan Prichard)  Rotary District 5060 Environmental Sustainability Committee. June 16, 2022. [online]

“Landscape fuel treatments and wildland fire management strategies within recent large fire events of north-central Washington State”(Susan Prichard)  Missoula Fire Science Lecture Series. April 28, 2022. [online]

“Landscape fuel treatments and wildland fire management strategies within recent large fire events” (Prichard, S., Povak, N., Lemons, R., and Griffey, V.) Northwest Fire Science Consortium Webinar. November 18, 2021.

“Climate change and the risk of Western fire activity.” (John Abatzoglou). IBHS Disaster Dynamics Academy, March 2022.

“Climate Change and Simultaneous Megafires in the Western US.” (Seth McGinnis). Presentation, CGD Seminar, Boulder CO, 1 March 2022. Online: https://www.youtube.com/watch?v=tt9HnbMjv9o.

“Climate change adaptation for western forests, watersheds, and communities.” (Susan Prichard). FEMA Region 10 Regional Interagency Steering Committee (RISC) Meeting. March 2022.

“Climate change impacts on demand for emergency resources.” (Reed Humphrey). FEMA Region 10 Regional Interagency Steering Committee (RISC) Meeting. March 2022.

“Western wildfires – adapting to a future with more fire.” (Susan Prichard). University of Washington Botanical Gardens, Seattle, WA, March 2, 2022.

“Common questions about adaptive forest management.” (Susan Prichard). Guest lecture, Environmental and Resource Management 101: Forests and Society. February 2022.

“Managing Future Risk of Increasing Simultaneous Megafires” (Melissa Bukovsky), National Center for Atmospheric Research, Research Applications Lab, December 2021.

“Landscape fuel treatments and wildland fire management strategies within recent large fire events.” (Susan Prichard, N Povak, R Lemons, V Griffey). Northwest Fire Science Consortium Webinar. November 18, 2021.

“Climate driven fire hazards: knowledge and limitations.” (John Abatzoglou). Bureau of Meteorology Annual Conference, Melbourne Australia (remote), November 2021.

“Common questions about adaptive forest management.” (Susan Prichard). Society of American Foresters, Washington Chapter. Webinar, November 11, 2021.

“Wildfire Smoke Engagement Workshop: Fire Ecology.” (Susan Prichard). SNAPP wildfire smoke engagement workshop Okanogan, WA, November 8, 2021.

“Common questions about adaptive forest management.” (Susan Prichard, P Hessburg, K Hagmann). UW School of Environmental and Forest Sciences Fall Seminar Series, October 28, 2021.

“The rise of fire in the Western United States: drives, impacts, and solutions” (John Abatzoglou). National Academies of Engineers, Sep 2021

“Climate Challenges for Wildland Fire Management” (John Abatzoglou).  University of California Wildfire Symposium Series, Aug 2021

Colorado Congressional Forum on Wildfire and Extreme Climate, Rep. Joe Neguse, Linda Mearns,  discussant, Highlands Institute Boulder,  August 2021.

“Compound Extremes Drive the Western Oregon Wildfires of September 2020” (John Abatzoglou) Pacific Northwest Drought Early Warning System webinar series, June 2021.

“Wildfire Risk Management and Decision Analytic Approaches” (Alison Cullen) Research Highlights, Evans School, University of Washington, Seattle, WA, March 19, 2021.

“Climate Change Impacts in Colorado” (Melissa Bukovsky) Protect Our Winters, Colorado Chapter.  January 2021.

“Climate information for fire management in SW Forests” (John  Abatzoglou)  Fire Science & Management in an Uncertain Future webinar series, December 2020.

“Wildfires and Climate Change in the Pacific Northwest.” (Susan Prichard) Association of Women in Science – Seattle Chapter. December 2020.

“Climate change and the risk of Western fire activity, Wildfires, Litigation, and What Science Can Tell Us” (John Abatzoglou) National Judicial College webinar, October 2020.

“Fuel Treatments and Megafires: lessons from the large fires in north-central WA” (Susan Prichard) University of California Fire Science Seminar Series. October 2020.

“Why are wildfires increasing in the Pacific Northwest?” (Susan Prichard) Washington on Fire Seminar, Washington State University Graduate and Professional Student Science Policy Initiative. October 2020.

“Wildfire Risk Management: Future Trends and Impact on Decision Making” (Alison Cullen) Cascadia Wildfire and Urban Smoke Webinar, Seattle, WA, 2020.

Climate projections and simultaneous wildfires

• Unless we take steps to address the situation – most of the Western US is projected to see numbers of simultaneous, 1000+ acre fires that historically occurred once every ten years happening once every five years – or even more frequently (McGinnis et al., 2022).
• In the US, the median number of large fires (i.e., greater than the historic 75th percentile) occurring simultaneously from July to September was about 3 times higher in 2010-2019 than it was in 1984-1993 (Podschwit and Cullen, 2020; Cullen et al., 2022).
• During the month of peak fire intensity in the US, the number of large fires (i.e., greater than the historic 75th percentile) occurring simultaneously was twice as high in 2010-2019 as it was in 1984-1993 (Podschwit and Cullen, 2020; Cullen et al, 2022).
• In Alaska, the average number of large fires (i.e., greater than the historic 75th percentile) during peak fire activity months approximately doubled in 2002-2019 compared to 1984-2001. In the Northwest US, the average number of large fires during peak fire activity months increased almost 30% between these two periods (Cullen et al, 2022).
• In the Northern Rockies region, conditions of more than 35 simultaneous wildfires 1000+ acres in size, which historically occurred once per decade, are projected to occur on average every two years by the end of this century (McGinnis et al., 2022).

Preparing for future wildfire seasons – resource preparedness

• As periods of co-occurring wildfire increasingly overlap across US regions, competition for suppression resources has been increasing, a trend which is expected to continue and intensify (Podschwit and Cullen, 2020; Cullen et al., 2020).
• The current capacity, in terms of hiring, staffing and preparing, of fire operations organizations is insufficient for responding effectively in the coming decades given the projected number and intensity of impactful fires (Podschwit and Cullen, 2020; Cullen et al., 2020).
• In the Western US, the season during which wildfires compete for suppression resources is projected to begin 2-4 weeks earlier and end 2 weeks later in 2040-2070 than it did during 1980-2010. Overall, wildfire season length will increase by 4-6 weeks (McGinnis et al, 2022).
• In 2021, the US national preparedness level reached its maximum (PL=5) at the earliest point in the year ever recorded, 14 July, indicating that suppression resources were already fully committed in response to simultaneous active fires at that date (Abatzoglou et al., 2021).
• With increasing intensity of wildfire seasons, national resources will be subject to ever higher levels of competition, necessitating increased reliance on international resource-sharing relationships (Bloem et al., 2022).

Proactive Forest Management (Mitigating fire risk under climate change)

• Fire management in the US must become proactive rather than reactive in the face of the lengthening of the simultaneous wildfire season by several weeks, alongside a notable increase in the risk of extreme fire weather.
• In recent decades, increased area burned by western wildfires has been associated with uncharacteristically large patches of high-severity, stand-replacing fire (Parks and Abatzoglou 2020, Hagmann et al. 2021).
• Because high-severity fire events can be catalysts for vegetation change, trends in large wildfires and burn severity have implications for rapid ecosystem shifts and declines in valued resources (Kemp et al. 2019, Stevens-Rumann and Morgan 2019, Coop et al. 2020).
• Combining western science and Indigenous knowledge systems is foundational to intentionally restoring and adapting western forest ecosystems (Kimmerer and Lake 2001, Lake et al. 2017, Roos et al. 2021).” (Prichard et al. 2021)
• Adaptive management is a learning-by-doing method of responding to ecosystem changes, informed by effectiveness monitoring (Lyons et al. 2008, Larson et al. 2013b).
• Restoring open forest structure and composition, favoring larger tree sizes, and reducing surface fuels can effectively mitigate future wildfire severity in dry, fire-prone forests, including oak and pine woodland and semi-arid mixed conifer forests of the western US.
• Despite calls to restore fire as a cultural and ecological process (e.g., The U.S. National Wildland Fire Cohesive Strategy), the dominant approach to wildfire management continues to be aggressive suppression. (Prichard et al. 2021)
• Under active fire suppression, forest infilling and fuel accumulation predisposes forests to high-severity fire when fire inevitably returns to the locations where it has been previously suppressed (North et al. 2015b)

Press/Coverage

Does Thinning Work for Wildfire Prevention. High Country News. February 2023.

Briefing with President Biden – climate crisis and Executive Order strengthening America’s forests, boosting wildfire resilience, and combating global deforestation.

Christian Science Monitor: Prescribed fires: Why they’re still trusted despite runaway blaze July 19, 2022

Fire danger escalating in Northern California as McKinney blaze erupts, Washington Post July 30 2022

August is coming. Prepare for climate calamity, Los Angeles Times July 28 2022

Americans Don’t Trust One of the Best Methods to Control Wildfires Time May 12, 2022

Climate change: wildfire risk has grown nearly everywhere – but we can still influence where and how fires strike. 30 June 2022. The  Conversation.

Climate change: wildfire risk has grown nearly everywhere – but we can still influence where and how fires strike. 30 June 2022. The  Conversation. https://theconversation.com/climate-change-wildfire-risk-has-grown-nearly-everywhere-but-we-can-still-influence-where-and-how-fires-strike-185465

The Return of Intentional Forest Fires: Scientists look to Indigenous practices. (Bioscience). 17 March 2022. https://doi.org/10.1093/biosci/biac016

Western US’s Worst Drought in 1,200 Years Brings Year-Long Fire Season. 13 March 2022 (Truthout) https://truthout.org/articles/western-uss-worst-drought-in-1200-years-brings-year-long-fire-season/.

‘Another reason to lose sleep’: California fires are growing more intense at night. (The Sacramento Bee). 25 February 2022. https://www.sacbee.com/news/california/fires/article258701563.html.

‘In wildfire ‘pivot’ experts question federal focus.’ (Roll Call). 28 January 2022. https://rollcall.com/2022/01/28/in-wildfire-pivot-experts-question-federal-focus/.

‘2021: The Year in Climate Change.’ (Sierra). 4 December 2021. https://www.sierraclub.org/sierra/2021-year-climate-change.

‘Why fire experts are hopeful.’(High Country News). 1 November 2021.  https://www.hcn.org/issues/53.11/north-wildfire-why-fire-experts-are-hopeful.

For Forest Blazes Grown Wilder, an Alternative: The ‘Good Fire.’ (Undark). 25 October 2021. https://undark.org/2021/10/25/for-forest-fires-grown-wilder-an-alternative-the-good-fire/.

Local fire ecologist addresses forest management debate (Methow Valley News) 1 September 2021. https://methowvalleynews.com/2021/09/01/local-fire-ecologist-addresses-forest-management-debate/

Experts call for expanded wildfire prevention tactics as fire seasons become more extreme (Yakima Herald-Republic) 7 September 2021. https://www.yakimaherald.com/news/local/experts-call-for-expanded-wildfire-prevention-tactics-as-fire-seasons-become-more-extreme/article_5ff9f141-1260-5bc9-9ad7-e0b35fe4aca3.html

An Update on This Year’s Wildfires: It’s Bad! (The Stranger) 26 August 2021. https://www.thestranger.com/slog/2021/08/26/60791981/how-do-we-stop-washington-wildfires-just-set-more-fires

Wildfires grow worldwide as climate sizzles (Associated Press), 19 Aug. 2021. https://apnews.com/article/us-news-fires-climate-environment-and-nature-california-7f186fbe7fade35c3a59cc53d66ff626

Forest management not so clear cut (Street Roots) 17 August 2021. https://www.streetroots.org/news/2021/08/17/forest-management-not-so-clear-cut

Wildfires: How are they linked to climate change? (BBC) 11 August 2021. https://www.bbc.com/news/58159451

What The UN’s Latest Climate Report Means For Colorado (Colorado Public Radio), 9 Aug. 2021. https://www.cpr.org/2021/08/09/un-climate-report-what-it-means-for-colorado

How years of fighting every wildfire helped fuel the Western megafires of today (The Conversation) 2 August 2021. https://theconversation.com/how-years-of-fighting-every-wildfire-helped-fuel-the-western-megafires-of-today-163165

State of the science on western wildfires, forests and climate change (UW News) 2 August 2021. https://www.washington.edu/news/2021/08/02/new-report-state-of-the-science-on-western-wildfires-forests-and-climate-change/

US heatwave: Could US and Canada see the worst wildfires yet? (Reality Check Team, BBC) 13 July 2021. https://www.bbc.com/news/57770728

States spend big as water levels fall, raising risks for catastrophic fires (The Hill) 29 June 2021. https://thehill.com/policy/equilibrium-sustainability/560733-states-spend-big-as-water-levels-fall-raising-risks-for

All software and data products generated by this project are publicly available. The code and documentation that we have developed for calculating fire indices in support of climate projections is publicly available on GitHub: https://github.com/NCAR/fire-indices. Visualizations appear in both published papers and above on this page.