-By Barry Janoff, Brandweek

NEW YORK Wal-Mart says it is serious about going "green" and encouraging its customers to also do so. To support its position, Wal-Mart this week will launch what it called "the most comprehensive environmental sustainability campaign" in company history.

The effort, via Interpublic Group's The Martin Agency, Richmond, Va., includes TV, radio, Internet and a 16-page insert in May issues of general-interest magazines. Spend for the effort was not disclosed.

Seven 30-second spots focus on various areas of sustainability to support in-store efforts around Earth Month 2008. One ad spotlights co-branded Coca-Cola T-shirts made with RPET, a material manufactured from recycled plastic bottles. (Click here for a review of the spot by 'Adweek' creative editor Eleftheria Parpis.)

Another supports the current rollout of Wal-Mart's six-SKU private label line of "organic, Rainforest Alliance and fair trade certified coffees."

The coffees will be sold under the Sam's Choice brand and will include Sam's Choice Fair Trade certified coffee, Sam's Choice Rainforest Alliance certified coffee and Sam's Choice USDA organic decaffeinated coffee.

Green in-store signage offers, "Earth Month '08. Save money. Live better." The Bentonville, Ark.-based retailer said that more than 50 products spanning various aspects of sustainability would be featured on store shelves in April and that more than 500 eco-friendly items would be available at Walmart.com.

Wal-Mart has made a big push toward environmental responsibility, employing Sustainable Value Networks -- which include Wal-Mart execs and leaders from supplier companies, environmental groups, academia and government -- to focus on issues such as energy and packaging. Wal-Mart in February hired Cleantech Group to monitor an online suggestion box and evaluate ideas for green product and services ideas from potential vendors.

The green campaign comes on the heels of a decision by the National Advertising Division of the Council of Better Business Bureaus that the retailer must revamp a current campaign which claims that shopping at Wal-Mart saves customers an average of $2,500 per family per year while people who shop at other stores do not.

NAD said in a statement that Wal-Mart could not make that implication in its ads, also via Martin. However, NAD accepted Wal-Mart's marketing claim that "its efficiency and size drive down consumer prices across the entire U.S. economy, generating that $2,500 savings regardless of where consumers shop."