Biofuels like ethanol, made from the byproducts of harvested corn, are worse than gasoline for global warming, claims a new analysis by the federal government released in the peer-reviewed journal Nature Climate Change.

Officials from the biofuel industry and Obama administration have already criticized the research, which contradicts the president's long-standing assertions that corn-based fuels burn much cleaner than regular oil and are an important tool in the effort to combat climate change.

In fact, the $500,000 study concludes, biofuels made with corn release 7 percent more greenhouse gases during the first years of use than does conventional gasoline, says a story by the Associated Press.

As well, the research notes, biofuels won't qualify as renewable fuel under an energy law standard set in a 2007.

The study appears to be a setback for programs promoting the development of cellulosic biofuels, which have received more than $1 billion in federal support -- but likewise have struggled to meet volume targets mandated by law, the AP report said.

Approximately half the initial cellulosics market is expected to be based on corn derivatives.

The study is being attacked as being too simplistic in its analysis of carbon loss from soil, which can vary over a single field, and also vastly overestimating how much residue farmers actually would remove once the market gets underway.

"The core analysis depicts an extreme scenario that no responsible farmer or business would ever employ because it would ruin both the land and the long-term supply of feedstock. It makes no agronomic or business sense," said Jan Koninckx, global business director for biorefineries at DuPont.

The company is on track later this year to finish a $200 million-plus facility in the city of Nevada, Iowa, that will have the capacity to produce 30 million gallons of cellulosic ethanol using corn residue from nearby farms.

DuPont paid for an evaluation that suggested the quality of the ethanol it will produce at the site will be 100 percent better than gasoline, as far as greenhouse gas emissions are concerned.

The federal government study is one of the first that strives to quantify how much carbon is lost to the atmosphere when the stalks, leaves and cobs that make up the harvesting residue are removed and used to make biofuel, instead of being left to naturally replenish the soil with carbon.

The research found that, regardless how much corn residue is removed from the field, the process still contributes to global warming.

"I knew this research would be contentious," said Adam Liska, the lead author and an assistant professor of biological systems engineering at the University of Nebraska-Lincoln. "I'm amazed it has not come out more solidly until now."

The Environmental Protection Agency's own analysis determined fuel made from corn residue, otherwise known as stover, would meet the energy law standard that requires cellulosic biofuels to release 60 percent less carbon pollution than gasoline.

Liz Purchia, an EPA spokeswoman, said in a recent statement that the study "does not provide useful information relevant to the life cycle greenhouse gas emissions from corn stover ethanol."

An AP investigation last year found the EPA's analysis of corn-based ethanol did not accurately predict environmental consequences of the process.