Present annual world energy consumption is about equal to the annihilation energy of 4 tons of matter.

Energy consumption matters both to our environment and our economy.

The factor most ignored in discussing interstellar flight is the kinetic energy that must be invested in the ship to make its tons of matter move at a substantial fraction of the speed of light.

When it comes to climate and energy, Gates is a radical consumerist. In his view, energy consumption is good - it just needs to be clean energy.

All I know about thermal pollution is that if we continue our present rate of growth in electrical energy consumption it will simply take, by the year 2000, all our freshwater streams to cool the generators and reactors.

The planet's environmental woes tend to be overlooked as we scramble for the latest high-tech gizmos - and conveniently ignore their energy consumption.