LCFS Land Use Change Assessment
In 2009, the Global Trade Analysis Project (GTAP) model was adopted with the original LCFS adoption. In 2011, the Board directed staff to continue working with interested stakeholders to update the indrect land use change (ILUC) carbon intensity values for various biofuels. Staff has been collaborating with stakeholders, and as part of the 2015 LCFS re-adoption, the GTAP model was updated and the AEZ-EF model was created to supplement GTAP's estimates of greenhouse gas emissions from various types of land conversions. This page provides information about indirect land use change and the models used for the land use change assessment and supporting documentation.
Indirect Land Use Change Analysis
- Detailed Analysis for Indirect Land Use Change from the 2015 LCFS re-adoption
- Land Use Change: The LUC.exe program calculates the land area changes and total post-conversion change in carbon associated with crop biomass. These GTAP results are required inputs to AEZ-EF. The package includes:
- LUC.tab: A TABLO program that performs the required calculations and writes results to the file "landcover.har"
- cropspec.har: Additional data required by LUC.tab for calculating changes in crop biomass carbon.
Current Version: GTAP and AEZ-EF Models
- January 2015: GTAP Model used for CARB ILUC Analysis posted on Purdue's website
In order to run a version of the GTAP Model used for the analysis of global land use impacts related to biofuels analyzed by Purdue/UC Berkeley for CARB, a user needs the GTAP Data Base license and GEMPACK model solver. The GTAP Data Base license is offered by the developer, Center for Global Trade Analysis, Department of Agricultural Economics, Purdue University. The GEMPACK is offered by the Victoria University. The following will help those interested in running a version of the GTAP model, used in CARB analysis, to go through the steps in purchasing the required licenses and instructions on where to download and how to run the model.
GTAP Data Base License
To run the GTAP model, the GTAP Data Base license is required.
What is the GTAP Data Base?
The GTAP Data Base is a fully documented global economic data base which contains complete bilateral trade information, transport, and protection linkages among regions for all GTAP commodities.
The GTAP Data Base is most commonly used with the GTAP Model and RunGTAP program.
Please register as a new member (existing member login directly). Follow instructions online to order the GTAP Data Base.
A Pentium PC with a hard disk, at least 256 Mb of RAM, Microsoft Windows 98, 2000, XP, or Vista.
GTAP is formulated and solved using GEMPACK, a flexible system for solving applied general equilibrium (AGE) models. RunGTAP, a program developed by Mark Horridge at the Centre of Policy Studies, Monash University, is a visual interfact to various GEMPACK programs. To run large GTAP model with RunGTAP, it is necessary to purchase the GEMPACK solver license. GEMPACK was developed at the Centre of Policy Studies, Monash University and is offered by the Victoria University. The licensee recommends that users purchase the introductory version, which is the least expensive. This allows the user to run the GTAP model used by CARB.
Archived Experiment details for LCFS: Corn Ethanol, Sugarcane Ethanol, and Soybean Biodiesel
Experiments can be replicated using two RunGTAP archives. These archives include all the experiment details required to replicate GTAP model runs for CARB.
Note: You can run these experiments with the RunGTAP software only if you have purchased the GEMPACK license as instructed above.
The RunGTAP program can be downloaded for free.
The RunGTAP archive containing experiment details for corn ethanol and soybean biodiesel land use impacts analyses can be accessed.
The RunGTAP archive containing experiment details for sugarcane ethanol land use impacts analysis can be accessed.
- December 2014: AEZ-EF Model v.52 and input sheet to be used with model
- February 2014: AEZ‐EF Model Report
Previous Versions: GTAP Model and Supporting Documentation
- February 2010: GTAP-SOY - Updated GTAP model customized for Midwest soybeans and supporting document
- February 2009: GTAP model and modeling files: Corn Ethanol and Sugarcane Ethanol
- January 2010: GTAP-SOY customized for Midwest soybeans and supporting documentation
- December 2009: GTAP-SOY - GTAP model customized for Midwest soybeans and supporting document
- February 2009: Biofuel Time - Integrated Model of Emission (BTIME) version 1.1 (by UC Berkeley, UC Davis, and Union of Concerned Scientists) - Modified by California Air Resources Board (used in the indirect LUC calculation of the LCFS staff report)
- February 2009: Emission Factor Tables (GTAP, Woods Hole)
- October 2008: RunGTAP version used for the corn ethanol analysis by ARB, UC Berkeley, and Purdue University
- It will require user to log in and verify that you have a version 6 database
- Individuals wishing to access must log in separately
- Useful reference papers for any written work using this model
- July 2008: GTAP Model version 6 from Purdue University, used to estimate the Land Use Change effect in biofuels for the LCFS Regulatory Process
- The associated data base is available to GTAP database subscribers
- Land Use database
- To download RunGTAP Software (a standard version)
- Importance of by-products
- Peer Review
- Results presented at CARB followed a paper, which will be updated in the coming weeks to reflect by-products
- The land use data base is documented in the following book chapters 2601, 2302, and 2603
- June 30, 2008: Release of Draft Land Use Change Calculation for Bio-fuels Production by University of California, Berkeley (GTAP model)