Madonna was among the many artists who wowed the crowd at London’s Live Earth gig, one of several held around the world on Saturday.

Nine concerts, featuring around 150 artists, took place in cities from Shanghai to Hamburg, in an attempt to highlight the issues of climate change and global warming.

The initiative is the brainchild of former US vice-president Al Gore, who has spent the past few years tackling environmental issues.

Gore appeared on a giant screen to introduce the Sydney show, which began at 1.10am BST on Saturday morning with a traditional Aboriginal welcome. Among the artists who appeared on stage were Crowded House and Jack Johnson.

The next concert to begin was the one in Tokyo, which featured local performers as well as rockers Linkin Park. Shanghai’s show and the concert in Johannesberg, South Africa followed shortly afterwards.

The London show, at Wembley began at 1.30pm and featured an all-star line-up, including performances from James Blunt, Razorlight, Keane, Corinne Bailey Rae, Foo Fighters and Red Hot Chili Peppers.

A number of hosts also appeared on stage to introduce the acts and highlight the aims of the concert. DJ Chris Moyles, US comedian Chris Rock, funnyman Ricky Gervais and veteran actor Terence Stamp were among those who took part.

Madonna rounded the concert off with a performance which featured a new song, Hey You, in which she was accompanied by a children’s choir.

Shows across the Atlantic in New York and Rio de Janeiro, featuring the likes of Kelly Clarkson, Kanye West, The Police, Bon Jovi and Macy Gray, were due to continue after the London show had finished, carrying on into the early hours of Sunday morning UK time.

The shows were expected to reach an audience of around two billion, via TV, radio and the Internet.