Pope Benedict says society has to meet the challenges posed by climate change and it has a responsibility to find "an ethical way to change our way of life." He made the comments during his trip to World Youth Day in Australia.

Stephen Douglas, from the Australian National University, says Benedict's views on climate change should not be taken too seriously.

"There's a growing body of what you could call symbolic policy; so these are things that are somewhat unfortunately referred to as 'motherhood statements.' So they're essentially warm and fuzzy statements about how we should be seeing things, how we should be caring for creation in Christian terms; but what we're not seeing is meaningful operational policy," said Douglas. "You're not seeing a restructure of the Catholic Church, or any other religious organizations, that would bring them up to speed with how they need to operate to address things like climate change."