20 years ago the RFS was passed into law. Instead of importing more oil the country was to pay farmers to grow more soybeans for biodiesel and more corn for ethanol to be blended with gasoline.
However, the 10% ethanol didn’t decrease the amount of gasoline consumed, as the messy process of growing corn and processing it uses up about 80% of the difference [1].
As a side effect, the extra demand for corn and soybeans increases the prices of food products.
The environmental impacts have also been considerable, with some 20 million acres of land converted to ethanol corn. Nor do biofuels reduce greenhouse-gas emissions. A 2022 Department of Energy report [2] concludes that “the carbon intensity of corn ethanol produced under the RFS is no less than gasoline and likely at least 24 percent higher.”
[1]
[2]
Environmental outcomes of the US Renewable Fuel Standard
https://www.pnas.org/doi/10.1073/pnas.2101084119
DB2