Alicia keys

( L - R ) Lenny Kravitz, Bon Jovi, Kanye west

EAST RUTHERFORD, N.J.:

Some of the world's biggest pop stars from the Red Hot Chili Peppers to Madonna and The Police played Live Earth concerts worldwide on Saturday to urge fans and governments to fight global warming.

Tens of thousands partied at concerts in Sydney, Tokyo, Shanghai, Hamburg, Johannesburg, London, Washington, New Jersey and Rio de Janeiro to hear Bon Jovi, James Blunt, Linkin Park and Shakira and many other performers.

Spearheaded byenvironmentalist and former U.S. vice-president Al Gore, the concerts spanned over 22 hours, ending at Rio's Copacabana beach and a New Jersey football stadium.

"You are Live Earth," Gore told the crowd at New Jersey's Giants Stadium, on a stage made with recycled tyres.

With hand raised as if taking an oath, Gore took the seven-point pledge he wants others to endorse, binding them to cut carbon emissions and to lobby governments and employers to do more to save the planet.

Gore wants world leaders to sign a treaty by 2009 to cut global warming pollution by 90 per cent in rich nations and more than half worldwide by 2050.

Pop idol Madonna ended the show at London's Wembley Stadium with a set including Hey You, written for Live Earth, while screens behind her flashed images of environmental disasters.

Madonna thanked Gore, "for giving the world the wake-up call it so badly needs and for starting an avalanche of awareness that we are running out of time."

As the Police played "Message in a Bottle," rapper Kanye West joined the band on stage and rapped the lyrics "We need some new leaders to follow ... Al Gore's got my vote."

Widespread cynicism

Following the model of 1985's Live Aid and Live 8 in 2005, Live Earth hopes to reach up to 2 billion people through radio, television and the Internet.

There has been widespread cynicism among music fans, campaigners and fellow rockers about the role of pop music, renowned for Learjets and limousines, to promote green living.

Backstage in New Jersey, singer KT Tunstall said the first year sales of her debut CD generated 650 million tonnes of carbon emissions, but she has tried to partially offset that huge carbon footprint through the planting of 6,000 trees.

At Wembley, Corinne Bailey Rae sang Mercy Mercy Me (The Ecology), Marvin Gaye's 1971 environment classic, also played by Alicia Keys in New Jersey. In London, mock rockers Spinal Tap reunited to perform Warmer Than Earth, in which the Devil complains about high temperatures in Britain.

About 30,000 people in Hamburg enjoyed performances by Yusuf, formerly known as Cat Stevens, and Shakira, despite rain.

The Shanghai concert was seen as key to Live Earth's success, after the International Energy Agency said China could become the top emitter of the main greenhouse gas, carbon dioxide, as early as this year, a claim disputed by officials.

The free Rio show, almost canceled over security concerns, drew as many as 600,000 peaceful attendees. Near the stage, revellers in bikinis and swimsuits frolicked in the surf.

In Antarctica the previously unknown band Nunatak played for 17 fellow researchers, allowing Gore to keep his promise to hold concerts on seven continents on the date 7/7/7.

Ludacris

( L - R ) Pharrell, Marcelo d2

( L - R ) John mayer, Macy Gray

Dave Matthews

( L - R ) Kelly Clarkson, Sting