The former Beatle is in talks with organizers about performing at the spectacular concert at London's new Wembley Stadium on Saturday (07.07.07).
According to reports, former US Vice President Al Gore - who has organized a series of concerts across the world to highlight the dangers of global warming - decided to personally approach McCartney after discovering the strict vegetarian and animal rights campaigner was a fan of his documentary "An Inconvenient Truth."
A source told Britain's Daily Mirror newspaper: "It's true that Paul has been asked to take part. He said the cause is very close to his heart and he has been impressed with what Gore has been doing to highlight it, but he's still deciding."
If McCartney, 65, declines the offer Madonna is expected to close the event.
The 48-year-old singer will perform a four-song set - including "Ray of Light" and "Hey You," a track she has written especially for the concert - but it has not yet been decided where in the schedule she will appear.
Other acts confirmed to perform include the Beastie Boys, Red Hot Chili Peppers, Keane, Snow Patrol and David Gray. Genesis, fronted by Phil Collins, will kick off proceedings.
The 24-hour Live Earth concert series will begin in Sydney on Saturday and continue across seven continents with shows in Tokyo, Shanghai, Johannesburg, London, Hamburg, Istanbul and Rio de Janeiro, before concluding in New York.
