The Live Earth concerts have drawn to a close, with the curtain going down in New Jersey in the US, after a finale performance from The Police.
Keith Urban and Alicia Keys at Giants Stadium, New Jersey
Rock stars around the world performed to hundreds of thousands of music fans to highlight climate change.
Concerts were also held in Washington, Rio de Janeiro, Johannesburg, London, Hamburg, Tokyo, Shanghai and Sydney.
The event was organised by former US Vice-President Al Gore, as part of his campaign to try to "heal the planet".
Mr Gore addressed the crowd at the end of the New Jersey event, urging the audience to act to save the planet: "Thank you for coming to Live Earth. Put all this energy in your heart and help us solve the climate crisis."
He also appeared at a smaller event at the National Museum of the American Indian in Washington, giving a speech which was relayed to the concerts around the world, calling on the developed world to reduce carbon emissions by 90%.
But critics have said it was hypocritical for performers who fly around the world on tours to push the message of cutting down on carbon emissions.
George Marshall of the Climate Outreach Information Network told the BBC: "Having the richest people in the world saying, 'Hey! We all need to cut back a bit!' is, let's face it, absurd."
Madonna brought London's Live Earth concert to a close. After performing Hey You accompanied by children in school uniform, the singer swore at the audience and told them: "If you want to save the planet let me see you jump."
Speaking from Wembley, Snow Patrol lead singer Gary Lightbody told BBC Radio 1: "We're here to learn how to make our tours cleaner. We already offset our travel on our touring, but our shows themselves are quite far behind.
"We're not the Red Hot Chili Peppers, who've been offsetting for years - and more power to them."
Reformed group Genesis, featuring Phil Collins, were among the first acts to perform at London's Wembley Stadium.
The Beastie Boys, James Blunt, The Foo Fighters and Spinal Tap also played.
Duran Duran opened their set with the perfect song for the occasion, Planet Earth.
"Everyone who did not arrive on a private jet put your hands in the air," said lead singer Simon Le Bon, who also raised his hand.
German concert-goers were treated to performances by Snoop Dogg, Enrique Iglesias and Yusuf Islam, while UB40 and Joss Stone were performing in Johannesburg.
The Sydney event began with a traditional aboriginal welcome before Australian politician and former Midnight Oil frontman Peter Garrett made an appearance, saying it was up to citizens of developed nations to push for action to reduce pollution.
"Your voice matters, make it heard," he said.
Reformed New Zealand group Crowded House were joined by many of the other Sydney performers at the end of their set, for a rendition of the 1991 hit Weather with You.
The Tokyo event was opened by the band Genki Rockets at the Makuhari Messe hall, east of the Japanese capital.
Japanese singer Ayaka urged people to do what they could. "We can start helping by doing something small," she said.
"I started to carry my own eco-bag so I don't have to use plastic grocery bags, and use my own chopsticks instead of disposable ones."
In New Jersey, actor Leonardo DiCaprio was among the celebrities introducing the acts.
"Our actions from this day forward will help determine just what sort of future we pass on to our children and to their children," he told the crowd at the Giants Stadium.
Responding to criticism that the event creates even more carbon emissions, organisers have insisted they were keeping the concerts as green as possible, with proceeds being spent on power-efficient light bulbs and other measures to offset the shows' emissions.
"We've booked this show with acts that were touring in the area at the time so we could keep the carbon imprint down," explained producer Kevin Wall.
Thousands of plastic cups were left on the Wembley Stadium floor at the end of the London concert, despite organisers urging the audience to put them into recycling bins provided.