http://news.yahoo.com/s/afp/20100719/sc_afp/usenergyclimatewarming

Major economies looked Monday at how to cooperate in shifting to cleaner sources of energy, with a top policy board warning the world's current path was unsustainable.

Senior officials from economies making up 80 percent of global Gross Domestic Product opened two days of talks in Washington in a US initiative to find common ground amid torturous negotiations on a new climate change treaty.

The meeting comes as the United States tries to end the worst oil disaster in its history, a three-month-long spill from a BP well in the Gulf of Mexico.

"Without major changes to the way we produce and in energy use, we will confront untenable risks to our collective energy security and to the environment in the future," Nobuo Tanaka, executive director of the International Energy Agency (IEA), told the delegates.

"Indeed, the Deepwater Horizon accident in the Gulf of Mexico is a tragic reminder of this," he said.

The IEA, which advises advanced economies, said in a recent study that without a shift from fossil fuels, energy-related carbon dioxide emissions -- which are blamed for global warming -- would nearly double by 2050.

The IEA said that, even leaving aside environmental benefits, a decision to make more than half of light vehicles eco-friendly by 2050 would save global consumers 112 trillion dollars -- although the costs of adjustment would be 46 trillion dollars.

"We still have formidable challenges before us, but each day we wait, the challenge becomes harder. Every year of delay adds 500 billion US dollars to the cost of action," Tanaka said.

US Energy Secretary Steven Chu, the host of the meeting, later announced one initiative -- lighter-colored paint on the roof of the Energy Department headquarters along with other agency buildings outside of Washington.

He said the project, to begin this summer, would better cool buildings and reflect more of the sun's heat, leading to thousands of dollars in annual savings on air-conditioning.

"Cool roofs are one of the quickest and lowest cost ways we can reduce our global carbon emissions and begin the hard work of slowing climate change," Chu said, adding that he would recommend that other US departments follow suit.

Delegates said the two-day meeting was likely to announce joint initiatives, although it was unclear how specific they would be.

One area of discussions will be on how to develop a cleaner form of coal, which makes up more than a quarter of the global energy supply and is politically sensitive in the United States and China, the top two polluters.

The clean energy meeting, which Chu expected to be the first of several, is an offshoot of the US-led Major Economies Forum, which brings key nations together to seek progress on fighting climate change.

Negotiations on a successor to the Kyoto Protocol, whose requirements for nations to cut emissions run out at the end of 2012, have been hamstrung by disputes over how much to demand of both developed and emerging economies.

The countries taking part in the clean energy talks are Australia, Brazil, Britain, Canada, China, Denmark, Finland, France, Germany, India, Italy, Japan, Mexico, Norway, Russia, South Korea, Spain, South Africa, Sweden, the United Arab Emirates and the United States.

The European Union is also participating, along with a number of international organizations.