This research effort tackles the challenges that simultaneous megafires currently pose to decision makers and stakeholders, and supports proactive planning for future scenarios to mitigate risk (NSF Growing Convergence Research #2019762). Megafires are fires that are unusually large or that require a complex and aggressive firefighting response because of dramatic threats to lives, property, and/or infrastructure. When multiple megafires occur simultaneously, firefighting resources may be strained beyond capacity with catastrophic results. To successfully advance the frontiers of fire science and management to mitigate risk at the intersection of natural and human systems, we are developing a highly convergent approach in a team comprised of researchers from University of Washington, NCAR (National Center for Atmospheric Research), and University of California, Merced. We bring expertise in decision science, climate science, statistics, and fire science to our collaboration with on the ground decision makers including fire managers, fire ecologists, and land managers for tribal and US government agencies.

We aim to strengthen risk management related to wildfire impacts with improved climate projections in support of decisions regarding land use, fuel and land management, and wildfire suppression, thereby helping to safeguard against the future loss of life, property, infrastructure, and natural resources.

Please contact Alison Cullen  with questions or to inquire about partnership opportunities. 

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  1. Higuera PE and Abatzoglou JT 2021 “Record-setting climate enabled the extraordinary 2020 fire season in the western United States” Global Change Biology 27(1):1–2 Online: 
  2. Abatzoglou JT, Juang CS, Williams AP, Kolden CA and LeRoy Westerling A 2021 “Increasing synchronous fire danger in forests of the western United States” Geophysical Research Letters 48(2) Online: 
  3. Abatzoglou JT, Rupp DE, O’Neill LW and Sadegh M 2021 “Compound Extremes Drive the Western Oregon Wildfires of September 2020” Geophysical Research Letters 48(8) Online: 
  4. Cullen AC,  Axe T and  Podschwit H 2021 “High-severity wildfire potential – associating meteorology, climate, resource demand and wildfire activity with preparedness levels” International Journal of Wildland Fire 30(1):30-41 Online: 
  5. Prichard SJ, Hessburg PF, Hagmann RK, Dobrowski S, Povak NA, Hurteau MD, Kane VR, Keane RE, Kobziar LN, Kolden CA, North M, Parks SA, Safford HD, Stevens JT, Yocom LL, Churchill DJ, Gray RW, Huffman DW, Lake FK, and Khatri-Chhetri P 2021. “Adapting western North American forests to climate change and wildfires: ten common questions” Online: Invited feature. Ecological Applications.
  6. Abatzoglou, JT, Cullen, AC and Prichard, S, Synchronous fires and fire danger challenge US capacity to respond, The Climate Circulator, September 29, 2021,
  7. Abatzoglou, JT, Battisti, DS, Williams, AP et al. Projected increases in western US forest fire despite growing fuel constraints. Commun Earth Environ 2, 227 (2021).
  8. Jain, P, Castellanos-Acuna, D, Coogan, SCP., Abatzoglou, JT & Flannigan, MD Observed increases in extreme fire weather driven by atmospheric humidity and temperature. Nat. Clim. Chang. (2021). doi:10.1038/s41558-021-01224-1

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..  


  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. 

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

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

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. 

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

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

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

Conference Presentations

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.

“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

“Multimodel uncertainty in projected changes of simultaneous megafires in the Western US based on NA-CORDEX regional climate Simulations”. (Seth McGinnis). AGU. 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

“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.

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


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 and Seminars

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

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

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

“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.

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

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

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

Colorado Congressional Forum on WIldfire and Extreme Climate, Rep. Joe Neguse,  L. O. Mearns,  discussant, Highlands Institute Boulder,  August 2021.

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

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

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


Wildfires grow worldwide as climate sizzles (Associated Press), 19 Aug. 2021. 

What The UN’s Latest Climate Report Means For Colorado (Sam Brasch, Colorado Public Radio), 9 Aug. 2021. 

States spend big as water levels fall, raising risks for catastrophic fires (Reid Wilson, The Hill) 29 June 2021. 

New Report: State of the science on western wildfires, forests and climate change (Michelle Ma, UW News) 2 August 2021. 

How years of fighting every wildfire helped fuel the Western megafires of today (Susan J. Prichard, Keala Hagmann, Paul Hessburg, The Conversation) 2 August 2021. 

Local fire ecologist addresses forest management debate (Ann McCreary, Methow Valley News) 1 September 2021. 

Experts call for expanded wildfire prevention tactics as fire seasons become more extreme (Kate Smith, Yakima Herald-Republic) 7 September 2021. 

Forest management not so clear cut (Jake Thomas, Street Roots) 17 August 2021. 

An Update on This Year’s Wildfires: It’s Bad! (Matt Baume, The Stranger) 26 August 2021. 

Wildfires: How are they linked to climate change? (Jack Goodman & Jake Horton, BBC) 11 August 2021. 

US heatwave: Could US and Canada see the worst wildfires yet? (Reality Check Team, BBC) 13 July 2021. 

The code and documentation that we have developed for calculating fire indices in support of climate projections is publicly available on GitHub: