In 2006, Wal-Mart’s then-CEO Lee Scott delivered a speech to employees asking them to think big and ponder, “What would it take for Wal-Mart to be that company, at our best, all the time?” He then went on to rattle off a series of sustainability objectives that included powering the entire company solely with renewable energy sources and to “sell products that sustain our resources and environment.”

Treehugger.com, for one, was dubious. In a seminal editorial entitled “It’s Getting Harder to Hate Wal-Mart“, Lloyd Alter wrote, “That it comes from Wal-Mart? We will wait and see.”

Fast-forward to Thursday, and Wal-Mart and Treehugger met again, this time as allies to explain to the masses Wal-Mart’s latest green pledge, slashing 20 million metric tons of greenhouse gas emissions from its supply chain within the next five years. In a sign of just how far-reaching this detente between one of the business world’s biggest polluters and the eco activist press has evolved, Treehugger even agreed to dedicate part of its site to host the official Q&A about the Wal-Mart announcement, which Wal-Mart itself plugged repeatedly during yesterday’s webcast. On the forum, the questions from greens were well-informed and blunt, but the tone was respectful and even hopeful. One commenter, for example, wanted to know where Wal-Mart could expect to “find big, quick wins” to meet its sustainability pledge. The old hippies must have been shaking their heads wondering, “Where’s the hate, man?”

For good measure, fellow collaborators on Wal-Mart’s ambitious carbon-cutting pledge include Environmental Defense Fund, ClearCarbon and the Carbon Disclosure Project. Wal-Mart’s transformation from mom-and-pop-store killer to model of corporate sustainability seems complete this morning. It’s even won over the most skeptical parts of the blogosphere. As the sustainable design blog, Inhabitat, wrote, “While we’ve explored our qualms about Walmart’s vast operations all over the world before on Inhabitat we applaud their decision to try to bring their sustainability to the next level, as well as set an example for other large retailers.”

Mission accomplished? Not exactly. There’s an equally dubious public to convince, though their skepticism about Wal-Mart’s sustainability commitment may prove more intractable.

Wal-Mart (with its British subsidiary, Asda) knew it had to involve the public on all communications social media channels at its disposal if it was going to get them on board. The message on Wal-Mart’s YouTube channel, for example, is that you, the conscientious consumer, can do your part by running the washer machine with cold water and only choosing the most energy efficient appliances. The response? Crickets. Just 110 people have bothered logging on to view the video and the lone viewer comment starts off, “I don’t believe in man-caused global warming or climate change or whatever they’re calling it this week. It’s a crock…a fraud.”

The message resonates a bit further on Wal-Mart’s Facebook page; there, 325 people click they “like” the news. It’s the comment section just below though that makes you wonder which planet Wal-Mart is trying to save. A cacophony of Climate Change naysayers, Winn Dixie patrons and oddball Wal-Mart watchers all but drown out any chance of an intelligent debate on the merits of adopting a carbon-neutral lifestyle. Case in point? One woman uses the crowded forum to campaign for a few pet causes. “Lower yours prices!!!! BRING BACK LAYAWAY!!!!!,” she bellows. Four minutes later she is back in the comments section, informing us, “my kids just made me toast from walmart.”

When Lee Scott asked the troops back in 2006 to consider what it would take to make Wal-Mart run “at our best, all the time,” he no doubt hoped his radical ideas to transform the way the company operates — from not just a sustainability standpoint, but from a much more open corporate communications philosophy, one that encourages public feedback through its social media channels — would win the favor of the organization, the activists who had it in its cross-hairs and the public. It’s been a remarkable achievement to win over the first two. Now, the hard part comes: to win over the crowds on Facebook.