Former President Bill Clinton took the stage at the U.S. Green Building Council’s sixth annual Greenbuild conference in Chicago yesterday morning and, before a crowd of 6,000 people who gathered to hear his keynote address, described the green building movement the nation’s largest economic opportunity since the country mobilized for World War II. “It’s not going to be easy, but we have to move away from the carbon economy,” Clinton said, adding that he considers green building to be “perhaps the most important cause we can be involved in today.”

In a lightly political speech—we are facing an election year, after all, and his wife is running for president—Clinton talked about the failed model of the Kyoto Protocol, the need for greater international cooperation, and the efforts of his Clinton Climate Initiative to effect change throughout the world. “It’s critical that we negotiate a successor to Kyoto by 2009 or 2010,” Clinton said, “and we need a broader consensus on China and India.” He added that the logic many people use to criticize the cost of green building—that China and India are doing nothing and, therefore, gaining a competitive advantage—was flawed and akin to saying that the world should just have fun until we burn the planet down. “That ensures failure,” he observed.