LONDON -- The U.S. energy secretary said Tuesday that he's had enough of talk about fighting global warming. He wants action and has pledged that America will act first to help move along the talk.

And if others, especially new No. 1 carbon dioxide emitter China, are waiting for U.S. action, they'll get it, said Steven Chu, a Nobel-Prize winning physicist who has long warned of the dangers of global warming.

"The U.S. will move, inevitably it will move first, as a more developed country we should be moving first, and I hope China will follow," he said.

Chu told reporters at a London conference organized by Prince Charles and Cambridge University that energy efficiency is critical to reducing the world's carbon footprint. He said simple measures like painting roofs white and encouraging home buyers to look at utility bills when choosing a house could play a key role in reducing greenhouse gas emissions.

"Energy efficiency is ultimately free money," he said.

Appointed by President Barack Obama to aggressively tackle climate change and shift the U.S. from reliance on foreign oil to green energy, Chu is one of 20 Nobel Laureates attending the seminar. Delegates will discuss scientific solutions to global warming ahead of a U.N. climate conference in Copenhagen.

The U.S. government is currently debating legislation that would impose the first U.S. limits on the pollution blamed for global warming. Obama has told Congress he wants a bill this year before the Copenhagen meeting in December.

U.S. Rep. Henry Waxman, chairman of the panel drafting the bill, has scaled back the required greenhouse gas reductions between now and 2020 from 20 percent to 17 percent.

Chu sidestepped questions of what kind of reductions in greenhouse gas emissions the U.S. would ask for at Copenhagen, and said action was more important than percentages and pledges.

"The success of Copenhagen will be determined by what countries really do. To define it as failure if developing countries do not sign up to certain criteria is not constructive at all," he said.
Chu said there were several simple steps would reduce the carbon footprint. Such measures include painting flat roofs white to reflect sunlight back away from the earth, keeping buildings cooler and reducing the need for energy-hungry air conditioners.

"Energy efficiency is not just low-hanging fruit; it is fruit that is lying on the ground," he wrote in The Times of London on Tuesday.

The Copenhagen conference in December is meant to replace the Kyoto Protocol, which focused on targets to reduce greenhouse gases.

The United States never accepted the 1997 Kyoto Protocol, citing costs to the economy and the lack of participation by developing countries such as China.

Chu says the new U.S. administration recognizes the need to overhaul its energy policy.

"The industrial revolution was a revolution in the use of energy. It offloaded from human and animal power into using fossil fuels," he said. "We have to go to a different new revolution that can severely decrease the amount of carbon emissions in the generation of energy."