The tone of the debate over global warming has changed a lot in the last decade. In the 90s, big companies like British Petroleum, Texaco and General Motors were funding efforts to debunk the theory. Today, it's common for these and other former critics to tout what they're doing to reduce carbon emissions. An example of this changing tone was on display last night at the Duke Mansion in Charlotte. Four years ago, the University of North Carolina at Chapel Hill started providing consulting services to businesses interested in getting serious about environmental sustainability. Kelly Boone helped start the company, called CSE Consulting. "The number of times my phone rings to ask me about, Can I help a company with this project, has increased tenfold - easily." Boone was part of a panel last night that included representatives of Duke Energy, Wachovia and Lowe's. They heard a presentation from The Climate Project, the organization stared by Al Gore. And they discussed challenges in combating that temperature change in world where the population is growing, and consuming more. "Some of these emerging countries, large countries, like China and India, want to be more like us. It's really opening our eyes that they want to be like us, but look what that's causing," says Pat Mumford, a vice president for Wachovia. Last year the company launched what it calls a green building plan by constructing offices that consume less energy and use environmentally-friendly materials. "When you build a building for your company, ask the architect, how can I use some of that water off the roof? How can re-use water or add an extra line for gray water? How can I reduce some of my energy consumption? It's not really rocket science, but each little bit adds up." It was a friendly audience at this event organized by the Charlotte Chamber of Commerce. If there were many global warming skeptics, they largely kept quiet. An exception was Ralph Groce, who also works for Wachovia. He's not convinced that humans are causing climate change. And he sees a lot of hypocrisy from businesses proclaiming they're green. He addressed Michael Chenard, the environmental affairs director for Lowe's. "There are so many discrepancies between the way we say we want to live, say we want to work, and what we actually do in value," he says. "You've got to make that business case, because every quarter you have to make your numbers. When you don't shareholders are battering your stock. It just goes on and on - the discrepancy between the way we conduct our business and this notion of sustainability and this notion of green." Chenard had quick comeback that drew some laughs. "First, I can say that we offer low-flow showerheads," he quipped. But a sense of virtue isn't necessarily driving all this environmental good-will. Panelist Greg Effthimiou of Duke Energy says it's also economics. "It makes business sense, and I think that's the key distinction between folks that are just trying to claim that they are green and sustainable, and companies that are actually looking at their bottom line and seeing how being environmentally-friendly, a steward in the community, and attracting and retaining a diverse workforce actually impacts their business," he says. And that's what Kelly Boone of UNC-Chapel Hill likes to hear. He says it doesn't matter what motivates business leaders to act. It's the results of those actions that matter most. I'm Greg Collard, in Charlotte.