Wal-Mart is not only pushing its suppliers to be concerned about the environment but also plans to involve its employees, customers and communities in the sustainability effort, CEO Lee Scott told a London conference sponsored by Britain's Prince Charles on Thursday.

In an interview with USA Today, Scott said the effort has been embraced by employees and has helped Wal-Mart with retention and recruitment.

As for suppliers, Wal-Mart has come up with a scorecard to grade their environmental progress and will "pick the ones moving in the right direction." Still, customers will decide which suppliers' products are available with their purchase choices, he said.

Scott said the company will challenge its associates and suppliers to come up with ways to remove nonrenewable energy from products Wal-Mart sells. It also will push suppliers to "make products that rely less and less on carbon-based energy," he said.

Scott said he's gotten strong support for this and other aspects of Wal-Mart's sustainability plan from major suppliers, including Unilever, PepsiCo and Universal Music.

"In some cases, they've been ahead of us and in other cases waiting for us to ask," Scott said in the interview. "But no one has pushed back to me."

Even seemingly small steps can make a big difference when you're Wal-Mart. In November, Wal-Mart announced it would outfit refrigerator cases in more than 500 of its stores with a light-emitting diode, or LED, lighting system.

Scott estimates that move alone will save Wal-Mart $3.8 million a year and reduce its carbon dioxide emissions by 65 million pounds.

Another aspect of the sustainability push is "zero waste." Scott says Wal-Mart associates will work with farms and others to see how food that can't be sold can be recycled. It is urging suppliers to recycle electronic waste and even the glass from TVs.

The move has created some unlikely alliances.

Fred Krupp, president of Environmental Defense, plans to hire someone this month to run a new office near Wal-Mart's headquarters in Bentonville, Ark. It is one of several environmental groups working closely with Wal-Mart.

"This has tremendous potential to impact positively on the environment because of the scale," Krupp said. "In some ways, Wal-Mart is the very symbol of the good things that come out of the market system and the bad, including the environmental damage."

He noted that there's plenty of room for improvement. Wal-Mart's greenhouse gas emissions are growing and projected to continue to grow, despite the retailer's plans to reduce them at each store. That's because Wal-Mart is opening so many new stores.

Scott scoffed at the suggestion that going "green" was designed to boost Wal-Mart's often-battered image as a corporate citizen.

"There really isn't anything I've seen (with its image) that changes customers' buying habits," Scott said. "That's the part of image I care about."