New figures released by Federal Treasury, suggest Australia’s population will rise by 13.5 million people, or 65 per cent, over the next 40 years.

This is due to a huge increase in both fertility and migration rates.

Environment groups have called on the government to stabilize or reduce the predicted growth, but big business generally supports the prospect of larger numbers of consumers.

Ben Eltham from the Centre for Policy Development believes the existing projection of nine billion people worldwide is unsustainable.

He's speaking here with 2SER's Ann Deslandes.