 Corporate moguls, policy experts and US senators spoke with one voice about global warming on Wednesday, telling a world forum the United States must take a lead role in cutting greenhouse gases if it wants to encourage China and India to do the same. At a Capitol Hill meeting that included representatives from the Group of Eight industrialized nations plus China, India, South Africa, Brazil and the European Union, Sen. John McCain put the case for action on climate change bluntly. "The debate is over, my friends," the Arizona Republican said. "Now the question is what do we do? Do we act, do we care enough about the young people of the next generation to act seriously and meaningfully, or are we going to just continue this debate and this discussion?" McCain said the push to reduce the greenhouse gas emissions that spur global climate change was a national security issue, and that voluntary efforts to limit those emissions from vehicles, power plants and other human sources "will not change the status quo." McCain and Senator Joseph Lieberman, a Connecticut independent, have pushed legislation that would set limits on the emission of greenhouse gases including carbon dioxide, and allow those that exceed them to trade with others that are under the limit, a plan known as cap-and-trade. Lieberman, who also addressed the group in the ornate Senate Caucus Room, noted growing momentum for US action "after many years of denial and inaction" on global warming. "I want to make a prediction, which is that the Congress of the United States will enact a nationwide law mandating substantial reductions in greenhouse gases before the end of this Congress or early in the next," Lieberman said. This session of Congress ends in late 2008. The Bush administration has rejected calls for mandatory limits on greenhouse gas emissions, maintaining that such caps would harm the US economy. Jim Rogers, the chief of Duke Energy, applauded the mandatory cap-and-trade approach, and stressed that if the United States did not act soon to cut greenhouse emissions, fast-developing China and India probably would not participate in any global emissions-cutting program. In one of his first speeches that addresses climate change, World Bank President Paul Wolfowitz called on countries to agree on a post-Kyoto global regulatory framework for reducing carbon emissions that does not punish the poor. The Kyoto Protocol on curbing greenhouse gas emissions expires in 2012. He said the challenge was to cut greenhouse gases while meeting energy demands that can help people escape poverty. "We cannot penalize countries escaping from poverty for what is the result of a fossil-dependent growth pattern in rich countries," he told delegates at a dinner on Wednesday hosted by the World Bank. Richard Branson, chief of Virgin Airlines and other ventures, said leadership and sacrifice were required to tackle global warming, but credited the United States for growing markets for renewable energy and green technologies. Branson announced last week in London a $25 million prize for the first person to find a way to scrub greenhouse gases from the atmosphere.