Iowa and Missouri sued New York on Thursday over its mandatory Greenhouse Gas Reporting Program, which imposes reporting requirements, compliance costs, and penalties on out-of-state fuel suppliers, including producers of ethanol, biodiesel and other biomass-derived fuels.
The suit was filed in the US District Court for the Eastern District of Missouri, alleging that the program requires fuel suppliers to register with New York and report the amount of liquid fuel that they may sell there, regardless of where the initial sale or production occurs.
Iowa and Missouri officials believe this violates the US Constitution.
In 2019, New York enacted a law requiring substantial reductions in the state's greenhouse gas emissions by 2030 and even greater reductions by 2040.
The court document stated that the law did not specify how those reductions would be achieved. Rather, it directed New York's environmental agency to issue regulations supplying those details. Those emissions reduction regulations have not yet been issued.
In December 2025, New York issued regulations establishing a Mandatory Greenhouse Gas Reporting Program, or the GHG Rule.
The rule does not set emissions limits. It imposes reporting and compliance obligations to generate information that New York intends to use to create regulations that will reduce New York's greenhouse gas emissions considerably by 2030.
The GHG Rule also states that New York may enter and inspect a reporting entity's property without notice, impose civil and criminal penalties, and enjoin any violations.
But the GHG Rule does not apply only to entities located in or doing business in New York. Instead, it reaches activity beyond New York's borders.
As currently written, the GHG Rule extends to fuel suppliers in Iowa and Missouri, as well as to AmFree's members in the biofuels industry, according to the court filing.
Iowa produces the most ethanol and biodiesel of any state in the US. Missouri is the thirteenth-largest ethanol-producing state.