“Green” was the word on everyone’s lips this year, as Al Gore collected his Nobel Peace Prize for raising awareness of climate change, hybrid vehicle sales surged up 49 percent from last year and the must-have accessory was a reusable cotton grocery bag that declared “I’m Not a Plastic Bag.”

In April the Supreme Court weighed in on the climate change issue, finding in Mass. v. EPA that not only does the EPA have the right under the Clean Air Act to regulate greenhouse gas emissions from new vehicles, but that it must do so.

“The decision is more important for what it stands for rather than on its own,” says Adam Kahn, an environmental partner with Foley Hoag. “It is part of and indicative of a much larger and rapidly developing consensus: that carbon regulation, throughout the economy, is both inevitable and is coming in the near term.”

Currently states are leading the way, with the Regional Greenhouse Gas Initiative continuing to recruit Northeastern states to commit to reducing carbon dioxide emissions. In September a federal judge in Vermont ruled that state limits on greenhouse gas emissions from new vehicles–originating from California standards–were not pre-empted by federal law, clearing the way for enforcement in at least 10 other states that adopted the standards.

“One key issue is whether there will be a national program of carbon regulation or whether we’ll continue to see what we’ve seen to date, which is individual states, regions and corporations taking the lead,” Kahn says. “There is increasing pressure on the federal government to take a lead to ensure consistent regulations and consistent policy. Time will tell whether that will be borne out.”

It appears the federal government is beginning to respond to that pressure. Sens. Joe Lieberman and John Warner in October introduced America’s Climate Security Act of 2007, which seeks to reduce emissions from the power, industrial and transportation fuel sectors by 15 percent in 2020 and 70 percent by 2050.