1. (a) Calculating Carbon Intensities. Fuel pathway applicants and the Executive Officer will evaluate all pathways based on life cycle greenhouse gas emissions per unit of fuel energy, or carbon intensity, expressed in gCO₂e/MJ. For this analysis, the fuel pathway applicant must use CA-GREET4.0 model (including the Tier 1 CI Calculators derived from that model) or another model determined by the Executive Officer to be equivalent or superior to CA-GREET4.0.

2. (b) CA-GREET4.0. The CA-GREET4.0 model (August 12, 2024) contains emission factors for calculating greenhouse gas emissions from site-specific inputs to fuel pathways and standard values for parts of the life cycle not included in applicant-specific data submission. The model is open source and publicly available at https://ww2.arb.ca.gov/resources/documents/lcfs-life-cycle-analysis-models-and-documentation and is incorporated herein by reference. CA-GREET4.0 includes contributions from the Oil Production Greenhouse Gas Estimator (OPGEE) model (for emissions from crude extraction) and Global Trade Analysis Project (GTAP-BIO) together with the Agro-Ecological Zone Emissions Factor (AEZ-EF) model for land use change (LUC).

   1. (1) Tier 1 CI Calculator for Corn or Sorghum Ethanol (August 12, 2024)
   2. (2) Tier 1 CI Calculator for Sugarcane Ethanol (August 12, 2024)
   3. (3) Tier 1 CI Calculator for Biodiesel (August 12, 2024)
   4. (4) Tier 1 CI Calculator for Hydroprocessed Ester and Fatty Acid (HEFA) Fuels (August 12, 2024)
   5. (5) Tier 1 CI Calculator for Landfill Biomethane (August 12, 2024)
   6. (6) Tier 1 CI Calculator for Wastewater Sludge Biomethane (August 12, 2024)
   7. (7) Tier 1 CI Calculator for Dairy and Swine Manure Biomethane (August 12, 2024)
   8. (8) Tier 1 CI Calculator for Organic Waste Biomethane (August 12, 2024)
   9. (9) Tier 1 CI Calculator for Hydrogen (October 1, 2024)

   Tier 1 CI Calculators, which incorporate emission factors and life cycle inventory data from the CA-GREET4.0 model, are used to calculate carbon intensities for Tier 1 pathways. The nine Tier 1 CI Calculators listed below are publicly available at https://ww2.arb.ca.gov/resources/documents/lcfs-life-cycle-analysis-models-and-documentation and are incorporated herein by reference.

3. (c) OPGEE. The OPGEE model is used to generate carbon intensities for crude oil used in the production of ultra-low sulfur diesel (ULSD) and California Reformulated Gasoline Blendstock for Oxygenate Blending (CARBOB).

4. (d) Accounting for Land Use Change.

   1. (1) The Executive Officer calculated LUC effects for certain region-specific biomass-based biofuels using the GTAP model (modified to include agricultural data and termed GTAP-BIO) and the AEZ-EF model. The GTAP model provided an estimate of the area and types of land cover conversions associated with increased biofuel demand and the AEZ-EF model estimated the carbon emissions associated with those land cover conversions. LUC values for six region/biomass/fuel combinations are provided in Table 6 below. The Executive Officer may require a fuel pathway applicant to use one of the values in Table 6, if the Executive Officer deems that value appropriate to use for a region/biomass/fuel combination not currently listed in Table 6, based on empirical LUC, biomass yields, and emissions factors.

   2. (2) If the fuel pathway applicant's region/biomass/fuel combination is not listed in Table 6, and no value in Table 6 is appropriate, the Executive Officer shall calculate a conservative LUC value based on the same modeling framework specified in subsection (d)(1) above and the best available empirical data. The Executive Officer shall use satellite-based, empirical estimates of land cover change attributed to biomass feedstock expansion in a region, along with emissions factors from the AEZ-EF model and empirical data on biomass feedstock yields to calculate the empirical LUC value.

      For the purposes of this section, “satellite-based, empirical estimates of land cover change” means estimates based on earth orbit satellite imagery and remote sensing products (e.g., Landsat, NASA's Moderate Resolution Imaging Spectroradiometer (MODIS), Planet), including LUC monitoring platforms and datasets (e.g., Global Forest Watch, Mapbiomas-Brasil) and peer-reviewed research articles or reports that utilize satellite imagery to track changes in land use patterns and vegetation cover over time.

      For the purposes of this section, “empirical data on biomass feedstock yields” means data sourced from governmental or intergovernmental organizations that maintain agricultural census data (e.g., U.S. Department of Agriculture (USDA), Food and Agriculture Organization of the United Nations (FAO), or agricultural production statistics from national governments).

      Table 6. Land Use Change Values for Use in CI Determination

      Biofuel

      LUC (gCO₂/MJ)

      2015 Region of Analysis

      Corn Ethanol

      19.8

      U.S.

      Sugarcane Ethanol

      11.8

      Brazil

      Soy Biomass-Based Diesel

      29.1

      U.S.

      Canola Biomass-Based Diesel

      14.5

      North America

      Grain Sorghum Ethanol

      19.4

      U.S.

      Palm Biomass-Based Diesel

      71.4

      Indonesia/Malysia

Note: Authority cited: Sections 38510, 38530, 38560, 38560.5, 38562.2, 38571, 38580, 39600, 39601, 41510, 41511 and 43018, Health and Safety Code. Reference: Sections 38501, 38510, 39515, 39516, 38571, 38580, 39000, 39001, 39002, 39003, 39515, 39516, 41510, 41511 and 43000, Health and Safety Code; Section 25000.5, Public Resources Code; 42 U.S.C. Section 7545; and Western Oil and Gas Ass'n v. Orange County Air Pollution Control District, 14 Cal.3d 411, 121 Cal.Rptr. 249 (1975).

History

1. New section filed 1-4-2019; operative 1-4-2019 pursuant to Government Code section 11343.4(b)(3) (Register 2019, No. 1).

2. Amendment of section and Note filed 6-27-2025; operative 7-1-2025 (Register 2025, No. 26).