When working with the world’s largest retailer, you come to expect the unexpected. But what’s truly exciting is to help drive the unexpected.

Last year, Environmental Defense Fund (EDF) worked with Walmart on a goal to reduce 20 million metric tons of greenhouse gas (GHG) emissions from its supply chain and product lifecycles over the next five years. This innovative program reaches beyond Walmart’s operations and into its vast supplier base and extensive product offerings.

Because of the program’s scope, Walmart has been creative in finding ways to meet its climate goal by working on a multitude of unique projects. The projects highlighted below not only tackle reductions in four very different products but also find reductions in various stages of the products’ lifecycles.

Showerheads
One of the efforts appearing on shelves in Walmart stores right now is a showerhead that reduces water use (and, of course, the hot water and energy used to heat that water). By redesigning a basic product and following up with proper marketing and product placement, Walmart can change water use in millions of homes across the world. This project has the potential to cut millions of tons of GHG emissions annually and significantly reduce the consumption of one of our most precious resources, water.

Eggs
Walmart’s ability to drive change is also evident in its grocery department. The nation’s largest grocer is testing an egg etching program where tracking, product, and expiration information will be etched on to individual eggs. This additional information will allow Walmart to replace the broken eggs in a carton instead of throwing out entire cartons due to a few broken eggs. While this project is based on a relatively simple concept, the potential environmental gains are staggering. This process could eliminate the unnecessary disposal of over one million eggs a day, save one billion gallons of water annually, and reduce GHG emissions by 100,000 metric tons a year.

This project proves that sustainability is a win-win for business as well – egg etching can potentially reduce production costs for Walmart by $50 million a year. It also demonstrates that there are carbon reduction opportunities throughout the production process (from the chickens, their feed, transport, and the energy in each of those components).

Light bulbs
Another effort focuses on getting the highly successful American compact florescent light bulb (CFL) project implemented in Mexico. In the United States, private label CFLs were created and aggressively marketed by Walmart to drive sales. CFLs have proven to be environmentally superior and more cost effective than many alternative lighting products. Now Walmart is strategically marketing CFLs in Mexico and looking for similar success abroad.

Clothing Labels
In January 2011, Walmart changed the care label on millions of clothing products to specify that they be washed in cold water. With the quality of laundry detergents available today, washing in cold water has proven to be effective as, and more energy efficient than, using hot water. This is another way that Walmart is utilizing its products and its influence to change consumer behavior and help its customers embrace energy savings. If only 5 percent of Walmart customers follow the new instructions and wash their laundry in cold water, this project could realize GHG reductions of 2 million metric tons a year. Customers could also save up to $124 a year on their energy bills.

When you’re working with a global retailer that serves 200 million customers a week, getting even a small percentage of consumers to change their behavior or purchase environmentally preferable products will lead to significant greenhouse gas savings. Some changes are relatively simple, while others are more complex. In the end, when you team innovation up with Walmart’s scale, any effort can have a potentially profound ability to impact behavior and reduce emissions.