California Wildfire Emissions Estimates
Wildfire is a major source of particulate matter emissions, which have been associated with increased hospital admissions and emergency room visits, acute and chronic bronchitis, asthma and chronic obstructive pulmonary disease (COPD), respiratory symptoms, premature death in people with chronic heart or lung diseases and reduce lung function growth in children. Wildfire also releases biogenic carbon dioxide (CO2) emissions and other greenhouse gases (GHG) that contribute to climate change. However, it is challenging to determine how much wildfire emissions contribute to anthropogenic climate change because wildfire emissions are part of the terrestrial carbon cycle, and when they occur in a healthy way, can bolster carbon sequestration rates and help preserve carbon stocks by the ecosystem services that they provide. (For more contextual information about wildfire GHG and climate change, see the FAQ.)
This webpage provides estimates of air pollutant emissions generated by the vegetations (e.g. trees, shrubs, grasses) and other burnable materials (e.g. structures, automobiles, etc.) consumed by wildfires. Because these emissions serve as an important input to modeling done for California’s State Implementation Plan (SIP), these inventories are developed to be day- and location-specific. Where these pollutants eventually end up in the environment is highly dependent on the specific terrain and the atmospheric dispersion conditions at the time of fire (e.g., wind direction, heat convection, etc.). The fate of pollutants can vary significantly from day to day and between different fires with similar characteristics. The emissions data presented here do not address the dispersion and fate of the pollutants. For more information about wildfire smoke reaching communities and how you can protect your health from smoke exposure, please see the additional links at the bottom of this webpage.
Emissions of Vegetation Burned in Wildfire
The figure below shows the emissions of particulate matter less than 2.5 microns in diameter (PM2.5) from vegetation burned in wildfires since 2000. The table provides summary statistics of vegetation wildfire emissions and fuels. Additional graphs are available in the Summary Graphics webpage. Emissions data for additional pollutants and by individual wildfires can be found under the Wildfire Emissions Data sub-heading.
2024 Wildfire Area (million acres) | 2024 Vegetation Fuel Consumed (million short tons) | 2024 PM2.5 (thousand short tons) | 2000-2024 Average PM2.5 (thousand short tons) |
|---|---|---|---|
1.02 | 13.3 | 308 | 289 |
Wildfire Emissions Data
Summary table showing the total emissions of each wildfire between 2015 and 2024
Detailed table of daily emissions of each wildfire between 2015 and 2024, broken out by flaming and smoldering emissions
A geospatial data visualization tool for seeing wildfire emissions generation data on an interactive map
Technical documentation of inventory methodology
Technical supplement: assessment of method performance (assessment conducted in 2025)
Geo-database available upon request
For a summary of the inventory methodology, see the Oct 16, 2025, public webinar presentation in the Webinar Presentation, Report, and FAQ section below.
Archive of Reports from Previous Years
This webpage was redesigned in 2026 to provide more detailed data about wildfire emission estimation based on the new inventory methodology implemented in 2025-2026. The webpage contents have replaced the previous report format. Previous reports are provided below for archival purposes only.
Wildfire Emissions & Burned Area Estimates 2000–2023 (published in 2024)
Wildfire Emissions & Burned Area Estimates 2000–2022 (published in 2023, updated with errata in 2024)
Wildfire Emissions & Burned Area Estimates 2000–2021 (published in 2022)
Wildfire Emissions & Burned Area Estimates 2000–2020 (published in 2021)
Technical documentation of inventory methodology, 2023 edition. CARB revamped the methodology in the 2025-2026 inventory cycle and reanalyzed the 2015-2023 inventory using the new methodology. 2000-2014 inventory could not be reanalyzed due to limitations in input data from non-CARB sources. Therefore, the 2023 edition of the technical documentation is still applicable for 2000-2014 estimates in the latest inventory release.
Emissions of Human-Made Materials Burned in Wildfire
A more systematic inventory of homes and other structures burned in wildfire has become available in more recent years, along with more up to date emission factors and fuel loading assumptions in scientific publication. These enable CARB to expand wildfire emission estimation to include human-made materials. CARB staff is currently developing a new emission inventory pipeline for estimating emissions of structures and automobiles burned in wildfire. The new data are expected to be available in late 2026.
Webinar Presentation, Report, & FAQ
WebinarOct 2025 | Public Webinar (October 16, 2025): California Wildfire and Prescribed Fire Emission InventoryThe California Air Resources Board (CARB) hosted a public webinar on updates to the statewide wildfire and prescribed fire emission inventory. CARB staff presented refinements to emission quantification methodology, expansion of activity data sources, and a new methodological framework for generating an event-based inventory by utilizing satellite fire detection data. In an event-based inventory, emissions are estimated for each day of fire and by their geospatially explicit location. These inventory enhancements will provide more detailed and accurate fire emissions information to support various air quality management applications and facilitate a better understanding of the impact of fire emissions on air quality. The inventory data also support tracking progress towards California’s statewide goals for climate change and land management. |
FAQSep 2022 | FAQ: Wildfire EmissionsAs California continues to see extensive impacts due to wildfires every year, CARB has prepared a Frequently Asked Questions (FAQ) document that discusses the agency's role in addressing emissions due to wildfires and prescribed fire. FAQ: Wildfire Emissions (Last updated Sep 16, 2022) |
ReportNov 2021 | Report: California’s Historical Wildfire Activity before Modern Wildfire Suppression (November 2021)This report provides an overview of California’s fire history over the past 1,500 years and summarizes the dynamic interactions of climatic, environmental and human drivers that shaped the fire landscape through time. It synthesizes the current scientific understanding of historical fire regimes and estimation of GHG emissions from historical fire before the 18th century. The report was prepared in response to Senate Bill 901 (Dodd, Statutes of 2018, chaptered 626). Working closely with the California Department of Forestry and Fire Protection (CAL FIRE) and academic and agency experts with research and practical expertise in historical and contemporary fire in California and the western United States, CARB staff conducted a comprehensive review of the available literature and quantitative data regarding historical fire emissions throughout the history of California’s diverse ecosystems. Report: California's Historical Wildfire Activity before Modern Wildfire Suppression |
WebinarDec 2020 | Public Webinar (December 1, 2020): Estimation of Greenhouse Gas Emissions from Forest Management Activities, Contemporary Wildfire, and Historical FireThe California Air Resources Board (CARB) staff hosted a public webinar on staff’s estimation of greenhouse gas (GHG) emissions from contemporary wildfire and forest management activities, and a presentation on historical fire activity before modern fire suppression. In the first part of the webinar, staff presented the methodology and estimation results of GHG emissions from wildfire and prescribed burn, as well as the amount of ecosystem carbon transformed by forest management activities (which may include tree harvest, removals, and planting; prescribed burn; and other vegetation fuels management to reduce fire risk). In the second part of the webinar, staff presented a scientific literature review of quantitative historical fire data that are needed for modeling fire emissions. The data and literature review focuses on the 1,400 years before modern fire suppression began in 1910. For additional information about CARB staff’s most recent assessment of ecosystem carbon transformation due to forest management activities, see the Natural Working Land Inventory program webpage. |
Additional Information & Resources
Protect Your Health During Wildfire Smoke Events
FAQ About Wildfire Smoke, Ash & Air Quality
Indoor Air Cleaners and Wildfire Smoke FAQ
Emission Inventory and Air Quality Analysis
Criteria Pollutant Emission Inventory (all emission source categories)
Exceptional Event Demonstrations
Air Quality and Meteorological Information System
Camp Fire Air Quality Data Analysis
Other Related Programs
CARB Wildfires General Landing Page