Pop stars in Tokyo and Sydney kicked off a global chain of climate change concerts on Saturday (July 7) aimed at persuading the world to go green. Al Gore, the former U.S. vice president, appearing as an animated hologram, said the concerts, which kicked off in Australia earlier on Saturday and will end at Rio de Janeiro's Copacabana beach, were the start of a three- to five-year campaign to promote awareness of climate change. Gore said he wanted Live Earth viewers to pressure leaders to sign a new treaty by 2009 that would cut global warming pollution by 90 percent in rich nations and more than half worldwide by 2050. Around 40,000 people filled the Aussie Stadium in Sydney to hear acts including Crowded House and Jack Johnson and 10,000 more turned up just outside Tokyo at the Makuhari Messe hall, where Linkin Park and Kumi Koda were among the performers. The Japan concert neared its climax as U.S. band Linkin Park took to the stage, but the show was interrupted for about 20 minutes as some fans rushed to the front. There has been widespread cynicism among fans, campaigners and even fellow rockers about using the world of pop, renowned for its conspicuous consumption, to promote green living. In Antarctica, the previously unknown band Nunatak, comprising two engineers, a marine biologist, a meteorologist and a polar guide at a remote British research station, have recorded a short set. The "gig" in front of 17 fellow researchers allows Gore to keep his promise to hold at least one concert on all seven continents on the date 7/7/7. In Hamburg, Colombian singer Shakira in a snug-fitting blue tank top and even tighter jeans quickly warmed up a shivering crowd drenched by heavy rainfall with a steamy performance. The 30-year-old pop star gyrated across the stage for nearly 30 minutes, performing hits such as "Hips Don't Lie" and "Don't Bother". With about half of the concerts under way, London prepared itself to rock at Wembley Stadium. Madonna is to headline the gig while others will take place in New York, Johannesburg, Shanghai, Tokyo, Sydney and Hamburg. The London line-up includes the Red Hot Chili Peppers, Kasabian, Black Eyed Peas, Duran Duran and Keane. Sir Paul McCartney and Justin Timberlake are said to be in talks to appear as surprise guests. The concerts will be carbon neutral, with all energy to Wembley Stadium and the other venues supplied by renewable sources. But the 'carbon footprint' of each act is likely to come under scrutiny.