A new study says ethanol does little to reduce greenhouse gas emissions and may actually be making climate change worse.

The study was funded by the oil and gas industry's lead trade group, the American Petroleum Institute, which has been fighting the federal program mandating refiners to blend ethanol into the nation's gasoline supply.

The study was led by long-time ethanol opponent John DeCicco, who has stood against the Environmental Protection Agency's Renewable Fuel Standard for years. The program directs refiners to blend ethanol and other biofuels into the nation's fuel supply.

"This is the first study to carefully examine the carbon on farmland when biofuels are grown, instead of just making assumptions about it," DeCicco said. "When you look at what's actually happening on the land, you find that not enough carbon is being removed from the atmosphere to balance what's coming out of the tailpipe."

DeCicco and his group of researchers from the University of Michigan found that the corn used to produce ethanol offsets only 37 percent of the emissions from burning ethanol. That is important because making ethanol from corn is what makes it a renewable fuel.

Using ethanol as a renewable fuel is supposed to be a factor in helping to reduce carbon emissions that many scientists blame as the cause of global warming.

The ethanol industry slammed the study as obviously oil-industry-driven and biased in its findings.

"This latest report is just another desperate attempt to discredit the nation's most successful clean energy program," said Emily Skor, CEO of the pro-ethanol group Growth Energy.

"The Renewable Fuels Standard is bringing cleaner, more affordable options to the gas pump, and those biofuels have helped to cut greenhouse gas emissions by 110 million metric tons every year — the equivalent of taking nearly 20 million vehicles off the road.

"Ethanol also has helped save consumers as much as $0.50 to $1.50 per gallon. More bogus climate science from the oil industry can't change that," she added.