The survey found that 21 percent of consumers say a product's reputation is the biggest factor they weigh when making purchasing decisions, followed by word of mouth and brand loyalty. Only 9 percent say green marketing is their top factor.

That may be because a third of the respondents say they don't know how to tell if a green claim is true, and only one in 10 says they trust such claims without question.

The research reports that although 87 percent of those surveyed say they recycle, the Environmental Protection Agency finds that just 33 percent of waste is diverted from landfills.

Research from The Hartmann Group, a consumer marketing firm based in Bellevue, Wash., generally concurs. Its January report, "Sustainability: The Rise of Consumer Responsibility," notes 88 percent of consumers engage in "sustainable behavior," 75 percent consider environmental and social aspects when deciding what to buy, and a third are willing to pay more for those products.

The research also shows about 56 percent of consumers are familiar with the term "sustainability," up only slightly from 54 percent in 2007. Fully 71 percent say they don't know which companies follow sustainability values, and 75 percent don't know what products are sustainable. The report notes that consumers relate more to terms like "saving energy" and "hope for a better world."