Over-consumption in rich countries

and rapid population growth in the poorest both need to be tackled to put

society on a sustainable path, a report says.

An expert group convened by the Royal Society spent nearly two years reading evidence and writing their

report.

Firm recommendations include giving all women access to family planning,

moving beyond GDP as the yardstick of economic health and reducing food

waste.

The report will feed into preparations for the Rio+20 summit in June.

"This is an absolutely critical period for people and the planet, with

profound changes for human health and wellbeing and the natural environment,"

said Sir John Sulston, the report's chairman.

"Where we go is down to human volition - it's not pre-ordained, it's not the

act of anything outside humanity, it's in our hands."