Melbourne, Oct 28 (IANS): Policies targetting population reduction will not immediately solve issues of global sustainability simply because the world population is now so huge that there is no quick fix to the "virtually locked-in" population growth, a reserach has said.

Even apocalyptic events such as a third World War or a devastating pandemic, leave alone family planning, won't do much to stop the ticking population time bomb, the researchers found.

The world, therefore, must focus on policies and technologies that reverse rising consumption of natural resources and enhance recycling, for more immediate sustainability gains, the study said.

"Even a world-wide one-child policy like China's, implemented over the coming century, or catastrophic mortality events like global conflict or a disease pandemic, are still likely to result in 5-10 billion people by 2100," said Corey Bradshaw, professor at University of Adelaide in Australia.

The researchers constructed nine different scenarios for continuing population ranging from "business as usual" through various fertility reductions, to highly unlikely broad-scale catastrophes resulting in billions of deaths.

"We were surprised that a five-year WW III scenario mimicking the same proportion of people killed in the First and Second World Wars combined, barely registered a blip on the human population trajectory this century," said Barry Brook from University of Tasmania.

"As our models show clearly, while there needs to be more policy discussion on this issue, the current inexorable momentum of the global human population precludes any demographic 'quick fixes' to our sustainability problems," Brook said.

"The corollary of these findings is that society's efforts towards sustainability would be directed more productively towards reducing our impact as much as possible through technological and social innovation," Bradshaw said.

The study appeared in the journal Proceedings of the National Academy of Sciences.