I've been harping about this for two decades, and here are just a few reasons why

RS 2011: People have known and screamed about this for ever so long, yet it keeps going

Once again, with gusto:

It Turns Out That Ethanol Is Worse For the Climate Than Gasoline

A study, published in the Proceedings of the National Academy of Sciences, found that ethanol mixed in with gasoline is not a very green alternative to using just gasoline. In fact, biofuels are at least 24% more carbon-intensive than gasoline due to “emissions resulting from land-use changes to grow corn, along with processing and combustion,” according to Reuters.

Many researchers have been making this point for years. They accuse the U.S. government of catering to the whims of big agriculture by mandating ethanol to be mixed in with gasoline in ever-larger percentages. Congress has been trying to eliminate the ethanol mandates because of the hell they play with engines.

A Department of Agriculture study had previously shown ethanol to be relatively benign and a greener alternative than gasoline.

“Corn ethanol is not a climate-friendly fuel,” said Dr. Tyler Lark, assistant scientist at the University of Wisconsin-Madison Center for Sustainability and the Global Environment and lead author of the study.

Some of you may remember that when the corn growers first persuaded Congress to mandate ethanol it was touted as an “oxygenator” that would cut air pollution. Even the NYT pointed out the fallacy of this argument because car manufacturers had long since switched from carburetors to fuel injection, and didn’t need and couldn’t use more oxygen in the burning process, So the corn holers and their congressional supporters just shifted gears and claimed that it would reduce our dependence on foreign oil, and then added a phony claim reducing phony global warming.

This is all about the huge corn growers and their campaign contributions. I’ve long argued that, were we to shift the Iowa primary to the end of the election season, we could stamp out this program forever, but for now, that hasn’t happened, and the politicians keep returning to Iowa to take the pledge. The only presidential candidate I’m aware of who stood up to these people and said he would work to end ethanol as we know it (and it wasn't Trump – he toed the line) was John McCain, and we know how that turned out.