The line-up for the Australian leg of the Live Earth concerts has been announced.

Among those playing at the event in Sydney on July 7 will be home-grown bands Silverchair and Wolfmother.

Also performing at the event will be Jack Johnson and the newly reformed Crowded House.

Johnson had to make a decision to perform in either America or Australia and reportedly did so on the basis of surfing conditions.

He said: "New Jersey and Australia are about the same distance for me, but Australia's waves are a lot bigger, so that made the decision easier for me."