Greentech Media

Two studies published in the Science journal in February found that corn-based ethanol could wind up spewing more greenhouse-gas emissions than gasoline (see Associated Press and Grist stories).

Tian said such controversy could eventually turn the public against some biofuels, resulting in the erosion of supportive legislation, such as the 51-cent-per-gallon subsidy paid to ethanol producers.

But more stories like those in the New York Times and Washington Post could be on their way.

After all, an industry capitalizing on being green is particularly vulnerable to criticism for environmentally unfriendly behavior -- and intentional polluting is equivalent to a cardinal sin.

Whether companies are creating solar cells, producing biofuels or running wind farms, they still are running businesses, said Joel Makower, executive editor of GreenBiz.com.

"You are never going to have a 100-percent perfect record in terms of ethics and integrity," he said.
 

-- Jennifer Kho contributed to this story.