This was a concert to spread awareness, nothing more. Live Earth was under a lot of fire as it was seen as a hypocritical waste of energy and resources to pull off the event. In hindsight, I think the goal of awareness had its heart in the right place, maybe it inspired people into action - but the problem doesn't lie with awareness, it lies with the execution of the event. It talked out both sides of its mouth. I think the event was somewhat misguided in that it caused more people to laugh at the hypocrisy, whether that hypocrisy was real or perceived.
And for those thinking Al Gore is an opportunist, that's an easy shot. Of course he's an opportunist. But he's been going on about climate change and awareness for over 20 years - long before dreams of a presidency and sainthood or whatever one wants to call it.
Anyway - my theory is rock n'roll is bad for the environment. :P ;)