Biologists, ecologists and economists are attending the Biological Extinction conference this week to explore what social and economic changes are needed to save the world's wildlife.
In a statement ahead of the event, they warned: "The living fabric of the world, which we are enjoyed in Genesis Chapter Two to protect, is slipping through our fingers without ourshowing much sign of caring."
With the world's population growing from an estimated 300 million at the time of Christ to 7.4 billion today, the Global Footprint Network says mankind is now using approximately 156 per cent of the Earth's sustainable capacity.
Paul Ehrlich, a biologist from Stanford University in California who has advocated for greater use of birth control to help limit population growth, is attending the conference.
He told the Observer: "If you look at the figures, it is clear that to support today's world population sustainably - and I emphasise the word sustainably - you would require another half a planet to provide us with those resources.
"However, if everyone consumed resources at the US level - which is what the world aspires to - you will need another four or five Earths.
"We are wrecking our planet's life support systems. We have the capacity to stop that. The trouble is that the danger does not seem obvious to most people, and that is something we must put right."
The attendance of Mr Ehrlich, who wrote the book The Population Bomb, at the conference has itself attracted attention, with nearly 11,000 people signing a petition calling upon the Vatican to withdraw its invitation to him.
The petition says: "It would be impossible to calculate the possible millions of deaths globally this man and his ideas may indirectly be responsible for."