Future population growth will be determined by which of four options we take as a species:
Option 1: No change. Continue on our current path of profligate resource use and waste. The world's population will reach a maximum in this century, then potentially drop to pre-industrial levels as it is overwhelmed by the effects of pollution and dwindling resources. We may survive the coming ice age, but we will be vulnerable to extinction from natural disasters such as asteroid and comet collisions.
Option 2: Live within our means. Live on what Nature can replenish, clean up pollution, and achieve zero population growth. With this sustainability option, the world's population will level off at or below the Earth's carrying capacity. Developing the ability to deflect comets and asteroids may prolong our collective lifetime until the death of plants.
Option 3: Settle the Solar System. While living sustainably on Earth, use some resources to place settlements on Mars. From Mars, settle the asteroids. This will allow our species to possibly survive until the Sun dies.
Option 4: Settle the Universe. Live sustainably on Earth, settle the Solar System, and develop technologies to send people to other star systems. Settle other star systems. Like an expanding sphere, humanity will populate our Galaxy and then other galaxies, outlasting our Sun.
Possible population trajectories for options 1-4. Solid lines are worst-case and dotted lines are best-case.
© 2005 Bradley Jarvis, AllRights Reserved