Ethanol had a lot to live up to. It was going to use our plentiful corn to set us on a path toward energy independence, while reducing the greenhouse-gas emissions from our cars and providing a boon to farmers. Congress showed its enthusiasm for corn ethanol with the 2007 energy bill, which mandated that the United States increase production of renewable fuels to 36 billion gallons, 15 billion of which could be corn ethanol, by 2022.

But now the anti-ethanol chorus is getting louder, and a growing body of research suggests ethanol may not be able to deliver on all of its promises.

Statistics vary widely, but several studies have shown that making corn ethanol is a net energy loser: The amount of energy required to create it exceeds the amount of energy it provides.

Other studies question its ability to reduce emissions. While a recent one done at the University of California, Berkeley, estimated that corn ethanol lowers emissions of greenhouse gases by only 13 percent (after taking into account the energy used to grow and process the corn), others have suggested ethanol is actually no better than conventional fuel in terms of emissions, when you look at the complete life cycles.

Then there is the land use question, the current hot topic that has many ethanol supporters reconsidering. Ethanol production obviously increases the demand for corn, which raises the price and drives farmers to find ways to plant more of it. Farmers are cutting acreage of other crops and expanding existing cropland into forests or grasslands. Once those are destroyed, they release their stored carbon dioxide. Now this is happening on a global scale. In the Amazon, for example, deforestation is occurring so massively that Brazil now ranks fourth in the world in carbon emissions.

A recent study in Science reported that when this effect is figured into the equation, corn ethanol produces almost double the emissions of gasoline.

Also among the unintended consequences of the ethanol boom is that its demand for corn is helping drive up food prices in this country and abroad, and contributing to worldwide food shortages.

Where do consumers come in? Do they want ethanol? That’s hard to know, since little research has looked at that question. Consumers have reported, and research has shown, that ethanol reduces fuel efficiency, making it more expensive for consumers to run their vehicles on it. And that’s with the benefit of ethanol’s subsidies, too  —  without subsidies, ethanol’s actual cost would be much higher.

In many other arenas, consumers have shown an interest in making environmentally friendly decisions and a willingness to do so even at some additional out-of-pocket cost. In a survey (commissioned by a company involved in the ethanol industry), 95 percent of drivers expressed a willingness to make the switch from conventional gasoline. When asked what would encourage them to actually do it in practice, some of the factors they listed were:

  • Lower price than gasoline (72%)
  • Desire to reduce the country’s dependence on foreign oil (59%)
  • Better engine performance (58%)
  • Desire to protect the environment (48%)
  • Proof that biofuels are environmentally friendly (43%).

That ethanol hasn’t widely demonstrated to consumers an ability to do any of these things is suggested on Internet message boards that overflow with complaints about poor mileage, engine corrosion, and, in areas where ethanol is becoming ubiquitous, suggestions about where unleaded gas is still available.

All of this doesn’t mean we should abandon biofuels altogether. But corn ethanol isn’t looking like much of an answer after all.