When it comes to going green, it's better to think big.

That's the argument being made lately by groups such as Greenpeace and the Environmental Defense fund. The reasoning: Large global companies can with a single decision have as much impact on the environment as tens of thousands of individuals.

Last week, this column looked at the difficulties consumers face when trying to spend their dollars in ways that will keep them and the planet healthier, reward the companies that are trying to be eco-conscious and push stubbornly old-school companies in a greener direction.

Our job as consumers, environmental groups say, is to encourage this responsible behavior with our buying decisions. So here are a few common-sense tips to guide you on an eco-friendly trip through the aisles of your local retailers:

Be Skeptical

Americans seem to have no problem with this piece of advice. According to a new survey from advertising research firm Ipsos Reid, 70% of Americans believe that when a company labels a product "green," it's just a marketing gimmick.

This skepticism is valid. In every category, but especially those where there are no government programs or standardized labels to guide you (like cleaning products or cosmetics), it can be easy for companies to use feel-good words like "natural" and even "organic" to create a healthy, greenish aura around products that aren't either one to more than a token degree.

For example, General Motors ( GM)makes hybrid trucks under its GMC and Chevrolet labels that garner some of the worst ratings for fuel efficiency and air pollution. I asked Wal-Mart ( WMT)how it manages to sell organic T-shirts for $4, a too-good-to-be-true price that makes you wonder what corners it is cutting. A Wal-Mart spokesperson said the T-shirts are made overseas with U.S. cotton, and that they are clearance items that originally sold for $5.77, a price still low enough to raise a skeptical brow.

The easy way to feel secure is to look for third-party labels that have known standards behind them. The USDA's organic label guarantees a minimum standard for a range of fresh and packaged foods and even natural fiber clothing .

Similarly, the not-for-profit Forest Stewardship Council adds its label to lumber and other products made from sustainably harvested wood that sell in stores such as Home Depot ( HD). And Transfair USA's Fair Trade Certified label assures, among other things, that products found everywhere from Whole Foods ( WFMI) to Starbucks ( SBUX) to your local grocery store are grown in a sustainable way.

You can also look for objective third-party monitoring. FuelEconomy.gov is a Web site run by the EPA and Department of Energy that grades automobiles for greenhouse gas emissions, air pollution and fuel efficiency.

Read 'Labels'

Ellis Jones, a sociology professor at the University of California at Davis, looks forward to a day when all consumer items carry standardized environmental impact labels similar to the nutrition labels that packaged foods carry.

Timberland ( TBL) already has a prototype to follow. The company's shoeboxes carry a "footprint" label that, among other things, tells how much energy it took to produce those shoes and what portion of it was renewable.

Until that happens, consumers can get beyond flashy marketing claims and do the equivalent of reading the label by going online.

Web sites like Treehugger and Grist are always quick to provide facts and discussion around green claims their writers believe to be hollow.

Jones analyzed piles of data from not-for-profit organizations, government offices like the Environmental Protection Agency and companies themselves to compile his Better World Shopping Guide. It gives a range of stores and products a grade from A to F for the level of social and environmental responsibility behind them. Many of these rankings are available on his Web site .

The activist group Co-op America runs the Responsible Shopper Web site, which gives no-nonsense summaries of where it sees major companies from Kraft Foods ( KFT) to Archer Daniels Midland ( ADM) pursuing admirable green initiatives and where it sees them coming up short.

And Climate Counts, a project funded by organic dairy company Stonyfield Farm (which is owned by French food giant Groupe Danone), recently listed the large companies it believes are taking climate change most seriously and graded their efforts to improve things.

Don't Play an All-or-Nothing Game

Unless you confine your shopping to consumer-goods companies like Clif Bar, Seventh Generation and Annie's, which started out with the intent of being environmentally responsible, you'll be hard-pressed to find a consumer company that doesn't have as much to criticize as to laud when it comes to environmental behavior.

But if you buy more green products at your local supermarket, the store is likely to stock more. Choose a corporation's environmentally responsible products over its conventional ones and it will roll out more of the former, as will its competitors. You can see this shift happening already.

Drugstore.com ( DSCM) carries a wide range of natural products, including brands like Seventh Generation , because those are what its customers prefer to buy, according to a spokesperson.

Practically every auto maker, including Toyota ( TM), still sells some sort of unwieldy gas-guzzling minivan, SUV or light truck. But when competitors saw the futuristic Prius flying out the door (the company sold 12,500 of them in September, up 24% from a year ago) they began developing hybrids of their own.

The Sierra Club even believes that some oil companies are better than others, and advocates that consumers encourage more responsibility in this industry by directing their gas dollars toward BP ( BP) and Sunoco ( SUN) and away from Exxon Mobil ( XOM) and ConocoPhillips ( COP).

So next time you head out shopping, think carefully about what you drive, where you gas it up, where you shop and what you load in the back of your car.

Somewhere down the line it can make a big difference.
Eileen P. Gunn writes about the business of life and is the author of "Your Career Is An Extreme Sport." You can learn more about her at her Web site.

If you liked this article you might like

Disney's Stunt Is No Help to the Planet

Disney's Stunt Is No Help to the Planet

Disney's Stunt Is No Help to the Planet

Disney's Stunt Is No Help to the Planet

Cities: Better for Green Living Than Suburbs

Cities: Better for Green Living Than Suburbs

Clearer Labels Make Smarter Consumers

Clearer Labels Make Smarter Consumers

Labeling Holds Product Makers Accountable

Labeling Holds Product Makers Accountable