The U.S. Environmental Protection Agency must reconsider its 2018 renewable volume obligations under the Renewable Fuel Standard because the agency failed to consider how the policy would affect endangered species, the U.S. Court of Appeals for the District of Columbia Circuit ruled.

In a suit brought in 2018, the Sierra Club and the Gulf Restoration Network argued that habitats of whooping cranes and gulf sturgeon could be affected if corn production is increased to meet federal standards for ethanol in vehicle fuels.

Claims made by refineries and energy companies that the RVOs were too low or too high were rejected by the court.

The EPA argued that it did make a determination when it responded to comments on the proposed standards by saying it could not attribute any damage to habitats or species to changes in the rule.