Today's quiz: How well do consumers understand "green" brands?

(1) They are savvy.
(2) They don't have a clue.
(3) They don't care all that much.
(4) All of the above.

The answer, judging from the results of this year's ImagePower Global Green Brands Study, is (4) all of the above.

Hey, who ever said communicating about "green" is simple?

The survey, which comes from advertising and marketing giant WPP, is based on interviews with about 9,000 people in eight countries.

In the U.S., where researchers conducted 1,200 interviews, consumers identified these Top 10 green brands:

1. Seventh Generation
2. Whole Foods
3. Tom's of Maine
4. Burt's Bees
5. Trader Joe's
6. The Walt Disney Company
7. S.C. Johnson
8. Dove
9. Apple
10. Starbucks, Microsoft (tied)

One important caveat: Consumers chose these brands from a universe of 45 brands in limited product categories, including personal care, grocery, household products and electronics -- which is why you don't see the Toyota Prius or Stonyfield Farm on the list:

If you want to argue that (1) consumers are savvy, read the first four names and stop. They four are what the researchers call "born green" companies, that is, companies that from the get-go set themselves apart from competitors by touting their environmental credentials.

Seventh Generation makes non-toxic cleaners and household products, Whole Foods sells lots of organic fare, Tom's of Maine uses only ingredients found in nature in its toothpaste and Burt's Bees offers earth-friendly personal care products.

"Consumers really get their authenticity," says Annie Longsworth, global sustainability practice leader for Cohn & Wolfe. Having reported on all four companies, I agree that they deserve to be on any list of green brands.

That's not so with the next name on the list, Trader Joe's, a privately-held company that doesn't reveal much about its supply chain, doesn't report on its footprint and has been a target of activists. [See my 2009 blogpost, Greenpeace ridicules Traitor Joe's.] The belief that Trader Joe's is green supports the believe that (2) consumers don't have a clue.

Trader Joe's ranking makes even less sense when compared with Walmart, which ranked No. 20.

Annie Longsworth theorized that Trader Joe's did well because shoppers perceive it as a "friendly, hippie" brand, and assume that it is also good for the planet. Walmart, by contrast, comes across as a big-box store (which it is, of course) and that's not associated with being green.

Walmart has a green corporate sustainability story to tell, Annie said, but "they haven't figured out how to make it a consumer story, yet." Much of Walmart's work has focused on its supply chain, which is invisible to shoppers.

[As it happens, when the list came out last week, I had dinner in Boulder with Hunter Lovins and Catherine Greener, two smart and insightful sustainability consultants. Both told me, unprompted, that Walmart's sustainability initiative was the best thing to happen to the environment in the U.S. in the past 10 years.]

Evidence that (3) consumers don't care all that much comes from their responses when they were asked whether it is very important to them to buy from a company that is "is environmentally conscious." About 38% said yes, but that's fewer than those who said it is very important that the company "offers good value," "is responsible," "is reliable," "offers high quality products or services," "is trustworthy," "cares about its customers," and "has a strong brand."

Having said that, consumers worldwide told the pollsters that they intend to purchase more environmental products in the auto, energy and technology sectors, as well is green products in the more traditional "in me, on me" categories of food and personal care.

This Thursday in New York, I'll moderate a panel of experts who will present the global and U.S. findings, and try to make sense of them all. We'll be joined by, among others, John Replogle, who was formerly CEO of Burt's Bee's and is now CEO of Seventh Generation, so he's led two of the top four companies on the list.

We'll have speakers from Cohn & Wolfe, Landor Associates and Penn Schoen Berland Associates (PSB), all of which are part of WPP, and from the sustainability consulting firm Esty Environmental Partners. There's no admission charge to the event; you can learn more here.