NEW YORK (CNNMoney.com) -- Wal-Mart Stores hosted former Vice President Al Gore at a conference Wednesday evening that the company said is the next step in its efforts to improve the environment.

The company said the conference at its Bentonville, Ark., headquarters, dubbed the quarterly sustainability network meeting, included Gore's presentation on the dangers of global warming, as well as one from officials of the Rocky Mountain Institute and the Evangelical Environmental Network.

The meeting also included discussions with Wal-Mart (Charts) suppliers on how sustainability can impact the supply chain and benefit the customer, according to the statement from the world's largest retailer. Suppliers who were at the meeting included Procter & Gamble (Charts), Sara Lee Apparel and Paramount Classics.

"We are all passionate about making real progress regarding the environment," said a statement from Wal-Mart CEO Lee Scott. "By working together, we can help each other save money, reduce greenhouse gas emissions and pass the savings on to our customers. Sustainability is good for the environment, and it's also good for business."

In addition to his remarks to the conference, Gore screened his movie, "An Inconvenient Truth," about the threat of global warming.

Earlier this year Wal-Mart announced that it would seek to eliminate 30 percent of the energy used by stores, with the corporate goal of eventually being fueled 100 percent by renewable energy .The retailer also plans to eliminate 25 percent of the solid waste from U.S. stores in the next three years, with the corporate goal of producing zero waste.

Wal-Mart also is targeting increased efficiency of its truck fleet by 25 percent over the next three years, with efficiency doubled within 10 years except in the North, where Wal-Mart utilizes white reflective roof membranes, resulting in a 10 percent lower cooling load.

The company has been the subject of criticism from labor and other public interest groups. One of those groups, WakeUpWalMart.com issued a statement saying it is skeptical about Wal-Mart's environmental goal.

"While we are glad Wal-Mart is talking about environmental sustainability, Wal-Mart's long record of inaction and empty rhetoric leaves us deeply skeptical about Wal-Mart's true intentions," said the group's statement.

The group called on Gore to help police Wal-Mart's environmental practices.

"We hope Vice President Gore will join with us in our national campaign effort to make Wal-Mart not just an environmentally-friendly, but an employee-friendly company as well," the statement said.

Related: Companies dip their toes into global warming debate.