Ecologist Paul Ehrlich shocked the world in 1968 with the publication of 'The Population Bomb,' which he co-wrote with his wife, biologist Anne Ehrlich.

Forty six years later, Paul Ehrlich says the main thing he got wrong was the impact that the doubling of the world population to 7.2 billion would have on the global climate system.

Dr. Ehrlich says the solution to climate change is universal access to birth control, abortion on demand, and the end to what he calls 'the disease' of growth economics.

Paul Enrlich is currently in Australia to catch a glimpse of one of Australia's rarest birds, the Orange Bellied Parrot.