Men work on the set up of the Live Earth concert stage in Rio de Janeiro
© AFP Antonio Scorza

NEW YORK (AFP) - Although staging such a planetary event has not been without headaches, such pop giants as Madonna and Police, backed by US politician-turned-campaigner Al Gore, hope to succeed where years of scientific warnings have failed.

"We're going to ask the two billion people estimated to be in the audience Saturday to take a seven-point pledge that is designed to change behavior and also to put pressure on political leaders in every country across the ideological spectrum," Gore told NBC television.

He will be urging the global audience to lobby industry and governments to take action to save the planet from climate change.

If nothing is done to stop the build-up of so-called greenhouses gases which allow light in but prevent heat from escaping, the consequences could prove disastrous, campaigners argue.

The Live Earth festivities start at 0200 GMT Saturday in Sydney, which passes on to Tokyo, then Shanghai, Hamburg, London, Johannesburg, New York and wrapping up in Rio de Janeiro, with a symbolic rendezvous in Kyoto, Japan and a base in Antarctica.

Some 7,000 events in 129 countries including the giant concerts are being promoted by Gore as part of his passionate bid to focus attention on the dangers of climate change.

Al Gore
© AFP/Getty Images/File Scott Gries

Gore announced on Friday that Washington had been added as a new location, four months after some members of US President George W. Bush's Republican party resisted attempts to hold a concert in the nation's capital.

"I'm happy to announce here on CNN that a surprise new concert venue is going to be the Mall in our nation's capital," Gore said.

The daytime concert will be held at the National Museum of the American Indian's outdoor plaza from 10:00 am (1400 GMT) and featuring country music stars Trisha Yearwood and Garth Brooks.

It was a bright note in the planning which has been beset by problems. A concert due to be held in Istanbul was called off due to security reasons.

And the Rio concert was nearly nixed by a judge who feared for the safety of the 700,000 expected to attend the free concert in Copacabana featuring Macy Gray, Lenny Kravitz, Pharrell Williams and Xuxa.

There has also been sharp criticism of the event, with skeptics charging that the luxury lifestyles lived by many jet-setting rock stars helps add to global warming.

Madonna
© AFP/Getty Images/File Evan Agostini

Bob Geldof, organizer of the 1985 Live Aid concert that set the standard for world activism through music, has also expressed doubts that Live Earth would be more effective than pressing government and industry to action.

But Gore called the concerts "an SOS, a wake-up call to the entire world. And it will launch a three-year global campaign to get the facts out to everybody in the world" through his Alliance for Climate Protection.

On Thursday Rajendra Pachauri, the chairman of the Intergovernmental Panel on Climate Change, said the world's poor would be the first to suffer from predicted increases in global temperatures, rainfall and extremes like drought and flooding.

Gore's Oscar-winning documentary "An Inconvenient Truth" argues that human activity is raising the Earth's temperature, threatening changes in weather patterns, the seas and endangering life on the planet.

His crusade against global warming has prompted calls for him to enter the 2008 US presidential race after having narrowly lost the 2000 vote. But he told NBC: "I don't expect to be a candidate again, ever."

At Wembley Stadium in London, musical acts will include the Red Hot Chili Peppers, Duran Duran, Foo Fighters, Black Eyed Peas and John Legend.

The Police, Smashing Pumpkins, Kanye West, Alicia Keys, Jon Bon Jovi, Roger Waters and Gore will take the stage at Giants Stadium outside New York.

Angelique Kidjo, Joss Stone and UB40 will play in South Africa.

Shakira, Snoop Dogg and Yusuf Islam (formerly Cat Stevens) will play at Hamburg and Linkin Park will play Tokyo.

Performances will be carried on national television networks around the world and on the Internet at http://liveearth.msn.com.

©AFP