The necessity of solar energy

The idea of limits to growth has, understandably, achieved notoriety since the days of Malthus and, more recently, the Club of Rome. However, there must be some limits to the ability of the Earth to sustain a growing population. Fortunately, population models suggest that the world's population will probably level out at about two to three times the present numbers over the next hundred years. The question is whether the Earth's resources are sufficient to sustain that population at a high standard of living for all. In this the key issue is energy. It is clear that present trends in energy consumption, especially oil, cannot be sustained much longer. Regardless of this, however, prudence demands a drastic reduction in fossil fuel consumption, in view of the possibility of global warming. It can be shown that, combined with greatly improved energy efficiency, a transition to a solar (renewable) energy based economy capable of sustaining the anticipated growth in the world economy, is possible, but the constraints are extremely tight.