Today is Earth Day -- a reminder to us all that we need to make an effort to treat the planet we live on with care and respect. Maybe a day of eco-awareness will lead to some permanent habits for many of us. Even a first step like recycling glass and plastic products would be immensely helpful if the habit could be started by millions of American consumers. What else can you do, though?

Wal-Mart Stores, Inc. (NYSE: WMT) issued a statement yesterday to reinforce the impact it's having on the environment due to consumers who are making more eco-aware purchases every day. Wal-Mart's "Live Better" index -- which tracks the consumer purchasing adoption rate of certain eco-products like energy-saving lightbulbs -- increased 66% this year alone compared to 2007. The index tracks five eco-product categories that are appearing in the shopping carts more and more among the retailer's 200 million yearly shoppers.

A few examples of categories in Wal-Mart's Live Better index include concentrated laundry detergent, compact fluorescent lightbulbs and organic milk. Sales of these items were tracked against normal, non eco-friendly items in the same category to help create the Live Better index, as customers make the conscious decision to purchase them (even at higher prices in most cases) compared to normal product in each category. Since April 2007, the retailer demonstrated that increased adoption of organic milk rose 37%, while compact fluorescent lightbulbs went up in consumer adoption to 47%.

Is Wal-Mart becoming a leader of promoting eco-friendly products? Being the world's largest retailer and all, anything it does to make these products more available to its shoppers can have an enormous impact. On Earth Day, it's good to see that impact being demonstrated.