• by Sarah Mahoney  @mahoney_sarah, April 19, 2011

RadioShack is running an electronics trade-in tied to winning a new eco-friendly car. AAA is offering greener driving trips. Nickelodeon is hosting the Big Help Earth Day, and even Oxi Fresh Carpet Cleaners is pronouncing itself extra environmentally friendly.

But as thousands of companies try and link their marketing messages to Earth Day, scheduled this year for April 22, a new study from OgilvyEarth finds that the vast majority aren't having any impact on consumer behavior.

While 82% of Americans have "good green intentions," only 16% are dedicated to fulfilling them. And the 66%--or "the Middle Green"—are pretty much ignored by marketers. Overall, 82% have no clue how to estimate their carbon footprint, and 70% would rather cure cancer than fix the environment.

"Many of the environmental messages are not just failing to close the Green Gap, but are actually cementing it by making green behavior too difficult and costly from a practical, financial, and social standpoint," the agency says in its release of the new study, called Mainstream Green: Moving sustainability from niche to normal. "Many of the world's leading corporations are staking their futures on the bet that sustainability will become a major driver of mainstream consumer purchase behavior. Unless they can figure out how to close the gap, there will never be a business case for green."