Secretary Naig Comments on Final Guidance Incorporating Updated GREET Model for Sustainable Aviation Fuel Credit

DES MOINES, Iowa (May 1, 2024) – Following yesterday’s release of guidance by the U.S. Department of Treasury and Internal Revenue Service on the 40B Sustainable Aviation Fuel (SAF) Credit, which incorporates an updated version of the GREET (Greenhouse gases, Regulated Emissions, Energy use in Technologies) model to measure the lifecycle emissions from SAF, Iowa Secretary of Agriculture Mike Naig provided the following comment:

“As the top producing state of lower cost and cleaner burning biofuels, sustainable aviation fuel is an emerging market with huge potential for Iowa agriculture. 

Unfortunately, the Biden administration is once again telling Iowa farmers that Washington D.C. knows best. The administration's proposal mandates rigid requirements that ignore the innovation of agriculture and fails to recognize farmers ability to incorporate the practices that work best for their individual operations. This administration has continually pursued a one-size-fits-all approach that puts domestic energy production, like homegrown ethanol, at a disadvantage to international competitors. Yesterday’s guidance is more of the same. 

While inclusion of the GREET model is a welcome step, the details need to be right, and the administration has more work to do. I know Iowa’s Congressional delegation will be working to ensure that Iowa’s farmers and biofuel producers will be able to realize the full potential that SAF offers.”


About the Iowa Department of Agriculture and Land Stewardship

Led by Secretary Mike Naig, the Department of Agriculture and Land Stewardship serves the rural and urban residents that call Iowa home. Through its 14 diverse bureaus, the Department ensures animal health, food safety and consumer protection. It also promotes conservation efforts to preserve our land and enhance water quality for the next generation. Learn more at

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