CARB comments on Federal Aviation Administration information requests and plans
Document Date
Description
Letter
February 2026
CARB submitted a comment letter to the Federal Aviation Administration (FAA) on the draft Screening Information Request (SIR), for the Continuous Lower Energy, Emissions and Noise (CLEEN) Phase IV Program
The Toxics and Risk Managers Committee (TARMAC) Emission Factor Tool is a collaborative online resource developed with several California Air Districts and the California Air Resources Board (CARB). This online resource is designed to provide emission factors and pertinent information from industrial and commercial sources.
Key Features & Search Functionality
The tool is designed for high-level filtering and granular data retrieval. Users can search the database using the following criteria:
Source Identifiers: SCC Number, SCC Name, and TARMAC Number.
Equipment & Fuel: Equipment type and specific fuel types.
Pollutants: Pollutant name and Emission Factor (EF) descriptions.
Regulatory: Agency source.
Data Organization
Information is structured into six specialized tables to provide varying levels of technical detail:
Table
Description
Simplified Table
A high-level overview of frequently accessed factors for quick reference.
Emission Factor Description
Qualitative data including specific names, agencies, and source classifications.
Emission Factor
Numerical values, units of measure (e.g., pounds per million cubic feet), and conversion factors.
Pollutant Table
Lists of chemical pollutants and associated classifications (e.g. HAPs, carcinogen, etc)
Health Table
Health-related metrics and risk data associated with specific pollutants.
References
Technical citations, original data sources, and regulatory validation documents.
User Resources & Exporting
Export Formats: Data can be exported directly from the dashboard in PDF or CSV formats for external analysis.
Documentation: A comprehensive user manual and field definitions list are available within the tool to assist users.
Important Note:
Regional Variability: Emission data and estimation methods vary by location. Always contact your local air district to confirm specific emission factors, reporting thresholds, and regulatory requirements applicable for a given facility.
Emission Factor (EF) – This emission factor record is the numeric value that acts as a multiplier, converting activity/usage data into total emissions.
EF Units – The units that the emission factor record is presented in.
EF Date – The year that the reference document was published with the emission factor.
References Table Definitions
Agency – The agency (district) claiming this emission factor record.
Document Link – Link to the (first) reference document for the emission factor record.
References – The reference document for the emission factor record.
TARMAC Number – The unique emission factor profile number by district.
Section – Refers to the specific section in the reference document that the emission factor record is based on.
Author – The creator of the emission factor/reference document that the emission factor is based on.
Emission Factor Description Table Definitions
TARMAC Number – The unique emission factor profile number by district.
Agency – The agency (district) claiming this emission factor record.
Agencies Share – This is all the known districts with the same emission factor record. Additional districts may use the same emission factor record but have not yet participated in the TARMAC EF Clearinghouse project.
EF Description – Written description of the emission factor profile, which may contain more specific information than the Equipment field.
EF Date – The year that the reference document was published with the emission factor.
Equipment – General description of the equipment.
Fuel or process – Either the fuel type or specific process for the equipment.
Prescribed fire is planned, intentional ignition applied by land managers to reduce vegetation fuels that feed potential future wildfire, reduce wildfire risk on communities and infrastructures, restore ecosystem health, and support landscapes that depend on periodic burning. It is a planned, carefully managed tool used across California and other parts of the United States and the world. Unlike large wildfires, prescribed burns are conducted under specific weather and fuel conditions to keep fire behavior low intensity and predictable. California has set ambitious goals to expand the use of prescribed fire to reduce hazardous fuel buildup, improve forest resilience, and help protect communities from severe wildfire.
This webpage provides estimates of air pollutant emissions produced by the vegetation and other natural fuels intentionally consumed during prescribed fire operations. These data represent the amount of pollutants released at the point of combustion on the day and at the location where burning occurred.
Where smoke travels after ignition depends on many factors, including weather, terrain, and the operational conditions of the burn. As a result, smoke movement can vary considerably from one prescribed fire to another, even when they have similar objectives or fuel types. The emissions presented here describe only the quantity of pollutants released—they do not reflect how smoke disperses or what levels of smoke may be experienced by nearby communities. For more information about how prescribed fire smoke may affect local air quality and tips for reducing smoke exposure, please see the additional links at the bottom of this webpage.
Summary of Prescribed Fire Activity and Emissions
The graphs below summarize statewide prescribed fire activity and associated PM2.5 emissions across California. In Figure 1, daily emissions patterns show that most PM2.5 from prescribed burning occurs during concentrated seasonal burn windows, particularly in the fall, with both flaming and smoldering combustion contributing to emissions. Emissions are generally low and sporadic through most of the year. The largest emission peaks occur in October and early November, where both flaming and smoldering emissions increase sharply, with smoldering generally higher during the largest events. This pattern indicates that most daily PM2.5 emissions from prescribed burning occur during a concentrated fall burn period. Figure 1 does not include additional prescribed burns for which the burner did not record a burn date and there was no satellite fire detect to fill in the burn date.
Figure 1. California Statewide Prescribed Burn PM2.5 Emissions, 2023.
Figure 2 presents the geographic distribution of prescribed burn PM2.5 emissions and burn acreage across California air basins. Majority of prescribed burns in California are in the northern part of the state. In other parts of the state, prescribed burn is conducted mostly in mountainous regions and areas covered with natural vegetations.
Figure 2. Geographic Distribution of Prescribed Fire PM2.5 Emissions (Left) and Burn Acreage Across (Right) Across California Air Basins, 2023.
Prescribed Fire Emissions Data
California Air Resources Board (CARB) staff revamped the methodology and the data sources of the Prescribed Fire Emission Inventory in the 2025-2026 inventory cycle. Published in 2026, the 2023 emission inventory differs from previous inventory vintages in the following ways: it integrates activity datasets collected and compiled by local/state/federal air and land management agencies, the most extensive data reconciliation effort among similar datasets to date; uses satellite fire detect data to fill in burn date that was not recorded by the burner; refines fuel consumption assumptions specific to fuel compartments; and employs emission estimation pathways that are specific to combustion phase (e.g., flaming vs. smoldering) and burn type (broadcast burn, pile burn, or air curtain incinerator or carbonizer). It is spatially and temporally explicit inventory with day-by-day emissions and location information. The following inventory data are available:
A detailed table of 2023 prescribed fire emissions, categorized by burn type (broadcast, pile burn, and air curtain incinerator or carbonizer) and further separated into flaming and smoldering emissions.
Appendix 1: Documentation of Fuel Characteristic Classification System Fuelbeds lookups for Air District and Interagency Treatment and Tracking System prescribed fire records.
Archive of previous inventory vintages:
Documentation of the methodology prior to the 2023 inventory:
Instructions: Go to the CEPAM Query Tool, select the inventory year and the geographic area that you want to look up, choose Source Type “Area,” and click “Run Report.” Navigate to Rx Fire Emissions by subsequently clicking the following: “MISCELLANEOUS PROCESSES,” “MANAGED BURNING AND DISPOSAL,” and scroll down to “664-RANGE IMPROVEMENT” AND “666-FOREST MANAGEMENT.”
For a summary of the inventory methodology, see the Oct 16, 2025, public webinar presentation in the Webinar Presentation section below.
Webinar Presentation
Webinar
Oct 2025
Public Webinar (October 16, 2025): California Wildfire and Prescribed Fire Emission Inventory
The 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.
This webpage provides summaries of public webinars, FAQs, and reports produced by CARB’s Fire Emission Inventory Team. The webinar summaries include the announcement, presentation slides, and recording. The information is listed chronologically with the most recent first. For more information about fire emission inventory, see the additional links at the bottom of this webpage.
Webinar
Apr 2026
Public Webinar (April 23, 2026): California Non-Wildfire Structure and Vehicle Fire Emissions Inventory Update
The California Air Resources Board (CARB) hosted a public to a webinar presentation on updates to the statewide non-wildfire structure and vehicle fire emissions inventory. CARB staff presented an updated methodology, including new activity data sources, consumption factors, and emissions factors. Updated emissions include both criteria pollutants and greenhouse gases.
Public Webinar (October 16, 2025): California Wildfire and Prescribed Fire Emission Inventory
The 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.
As 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.
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.
Public Webinar (December 1, 2020): Estimation of Greenhouse Gas Emissions from Forest Management Activities, Contemporary Wildfire, and Historical Fire
The 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.
Zoom Call - Please cut and paste public registration link into browser: https://us06web.zoom.us/webinar/register/WN_nDkPGI-tTv6PERoXoeqfSg?utm_medium=email&utm_source=govdelivery
