Hawking predicts

Stephen Hawking has said that mankind must move to outer space within a century or it will become extinct, Professor Stephen Hawking cited war, resource depletion and overpopulation as three of the reasons the existence of the human race will come under pressure.

As things stand at the moment it is hard to disagree with him, but he isn't allowing for the earth's ability to self regulate. Throughout history, the earth has purged itself of unwanted inhabitants, recycling all the waste products and producing alternative life forms in the eternal ebb and flow of existence. Even man made war is somehow factored into the future direction the earth takes. In other words, no matter what course of action mankind  takes, nature has already taken it into consideration.

Hawking worries about war. Why not? Despite the prospects of war amongst the strongest nations is diminished, there are several 'rogue' countries who could trigger a global conflict. Religious based conflict, too, is becoming likely with the accelerated proselytization of Islam, disturbing older entrenched religions.

Depletion of resources can be a worry, especially hydro-carbons, but I believe that new resources can be found including the increased use of primal solar power. Nuclear power is also an abundant potential source of energy. With energy all the resources we need can be synthesized.

Overpopulation will put a huge burden on the ability of mankind to grow enough food. New methods of growing food and more efficient use of the land will be found but as natural disasters seem to be increasing, more and more previously fertile land is being taken out of production.

In recent years we've had the SE Asian tsunami, the Haiti earthquake and now the Pakistan floods. It seems that the earth is already taking steps to reduce the population. This could be just the start. The recent bird-flu scare was a warning of what could happen if a pernicious virus takes hold. Huge communities could be wiped out on a scale unheard of with meteoroligical or geological disasters.