For the bulk of human history, people used renewable energy.
They burned plant material, usually wood to create fires for light, warmth, and cooking.
Following the birth of agriculture 10,000 years ago, animals and human muscle power was used to plow fields, carry burdens, and pull up water from wells.
Only much later, with the Industrial Revolution, people began to exploit non-renewable fossil fuels, such coal, and later, oil and gas.
These concentrated energy sources made the creation of modern civilization possible, and today we have become energy addicts consuming more and more as the world develops.
However, this cannot continue.
People may debate how much oil coal is left under the ground or sea, but one thing is certain: the supply of fossil fuels is finite.
We may not know when this energy sources will run out, but one day it will, and the impact is likely to be terrible.
We need a transition for in the way we obtain and use energy.
But how are we to do it? Some suggest we should turn to nuclear energy as a virtually inexhaustible energy source.
They claim that nuclear energy is clean and produces no greenhouse gases.
This might be true, but the risk of an accident along the lines of Chernobyl and Fukushima or the spread of nuclear materials to a terrorist organization or state make our Reliance on nuclear power unacceptable.