Slowly but surely, companies will voluntarily seek out a green stamp of approval from a organization that promotes the sustainability concept.

If you don’t believe it, just ask the 100,000 companies that supply Wal-Mart.

The chain has overnight become the most potent mover of environmentalism, far more potent than EPA because companies that want to do business with Wal-Mart have to provide all sorts of sustainability information. Wal-Mart’s using the information to create a Sustainable Product Index that will slap a green rating on all products on its shelves.

But this is just the beginning of the retailing revolution, according to futurist Bob Johnansen, with Palo Alto, California-based Institute for the Future and author of Leaders Make the Future.

The not-too-distant future will feature everyday shoppers checking the greeniness of products instantaneously with simple apps on their cell phones. Shoppers looking to buy green will simply point their cell phone at the bar code on a product and get sustainable ratings on that product before they make their selection, Johansen told attendees at the Green Business Conference here in San Francisco.

And, what could be troubling for traditional corporate marketers, Johansen says, is that they’re losing control of the message because the Consumer Reports-type green ratings will be provided not by the manufacturer, but by major change makers like Wal-Mart or third-party eco-conscious organizations. Think of the movies Terminator and Minority Report where instant analysis is presented to man and machine.

In effect, consumers will instantly obtain product comparisons and ratings — like how far this product had to travel to a store, which is a measure of a product’s contribution to greenhouse gas emissions — well before the traditional marketer can influence a sales choice at a checkout counter.

The technology to be able to deliver this type of sustainability rating already exists. It’s basically the same use of technology that lets you find a nearby restaurant on your iPhone. So it won’t be long before companies will have to respond to this new technology, a change that will be driven by the marketplace, not by government regulation.

To be prepared, companies may want to consider tracking their own environmental footprints, such as indirect GHG emissions, waste vs. recycling rates, water consumption, etc.  Then companies will want to tout any reduction in related pollution and explain how that change makes the company greener.

Tags: carbon footprint, environmental footprint, Leaders Make The Future, Sustainable Product Index, Terminator, Wal-Mart