AirLockAlpha.com

Yes, The Doctor is also a great big fan of the environment. At least the actor who plays the current incarnation of the lead character in "Doctor Who" is.

David Tennant surprised crowds at Wembley near London over the weekend with a special appearance to introduce the band Pussycat Dolls at that location of the Live Earth concert festival.

"Back in 2005, when I was Christopher Eccleston, we saw one of the largest increases on record of CO2 [carbon dioxide] in the atmosphere," Tennant told the crowd of hundreds of thousands of people, referring to the actor who portrayed The Doctor in the first season of the revived "Doctor Who."

"Unless we keep the rise in global temperatures to under 2 degrees, by the time I'm Daniel Radcliffe or Wee Jimmy Cranky, I won't be able to save the planet," he said. "I may not be here to help you, or I might, but I'll be played [by then] by that bloke from 'Any Dream Will Do.'"

The Live Earth concerts borrow a lot from the 1980s Live Aid concerts to fight hunger, and the later revival of Live 8 in 2005. The concerts are taking place at Wembley Stadium near London; Giants Stadium in New Jersey; the National Mall in Washington, D.C.; Aussie Stadium in Sydney, Australia; the Coca-Cola Dome in South Africa; two locations in Japan as well as venues in Germany, Brazil, China and even Antarctica.

The festival was a brainchild of former American Vice President Al Gore, and is meant to provide awareness of global warming and other environmental conditions, as well as Save Our Selves founder Kevin Wall.

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