“The governments we get permits from are asking for green buildings; the investors are beginning to ask for green; and, most importantly, the customers–in the last 18 months–are asking for it.”

Rakowich said his company has a global reach and it's clear that the US is playing catch up, for now. Many of his European customers benefited from their countries signing on to the Kyoto Treaty, limiting their carbon footprint well before their US counterparts had embraced carbon neutrality as a way of doing business.

Now that the US is onboard, however, it's full speed ahead, according to the third panelist, Starwood Capital Group's Barry Sternlicht. “The scientific debate is over,” he said. “The US is catching on late,” but its developers are aggressively pursuing green projects.

For real estate, energy is a huge variable,” Sternlicht said, but added that the green building movement is growing due to a combination of factors, including societal ones. “Yuppie parents are more involved [than their own parents]. They're socially conscious and very concerned about their children's health and well being.”

Thomas said green, or LEED certification, can be achieved fairly easily these days. “They key is to start thinking in those terms from the beginning of the project, when you put together your team of architects and property managers. You can obtain the silver level with little or no additional costs.”

Thomas added that when planning a project he keeps two things in mind when thinking green: “We focus on energy savings. That's a key to make the economics work. We also focus on things that impact productivity–that's what gets the attention of tenants, and there's strong potential for savings.”

While most of the industrialized nations around the globe have embraced the greening of real estate, some of the emerging countries are still struggling with the concept–namely India and China. It can become a dilemma, on whether to fund those projects that are not environmentally sensitive, according to Sternlicht.

“Sometimes you can't see the project in front of you,” he said, “because the smog is so thick.”