New study finds California’s soybean ILUC values are outdated

A recent study commissioned by Clean Fuels Alliance America and Farmers Fueling the Future, a biofuel-research initiative between the American Soybean Association and the Iowa Soybean Association, finds that California’s indirect land-use change (ILUC) assumptions for U.S. soy-based biodiesel and renewable diesel are outdated, lacking modern agricultural practices and current science.

The analysis, “Land Use Change Emissions Associated with Soybeans: Considerations for California’s LCFS,” conducted by Life Cycle Associates, highlights substantially lower ILUC emissions for soy-based fuels than those currently used by the California Air Resources Board.

Considerations include advances in economic modeling, land-use data, yield responsiveness, trade patterns and carbon-stock measurements.

CARB last updated its soybean ILUC value in 2018 using modeling tools and data that predate many of today’s improvements in agricultural productivity and global market dynamics.

The latest research shows ILUC values well below CARB’s current assumptions calculated with more recent global data through updated Global Trade Analysis Project modeling.

According to the report, improvements in modeling and data inputs have consistently reduced estimated ILUC emissions for soy-based biodiesel and renewable diesel, producing results that better align with observed land-use and market behavior.

“This study confirms that today’s farmers are meeting growing clean-fuel demand through higher yields and responsible practices—not land expansion,” said Dave Walton, executive board member for Clean Fuels and the American Soybean Association. “CARB must modernize its approach and base its values on today’s science to accurately recognize the real carbon benefits of soy-based biodiesel and renewable diesel.”

According to Clean Fuels, the findings underscore the need for California’s Low Carbon Fuel Standard to reflect current data and real-world agricultural performance as the state works to decarbonize its transportation sector.

The full study is available on Clean Fuels’ website here.