We must appreciate how unusual the Earth is in having an atmosphere with low carbon dioxide (0.03 per cent) and high oxygen concentration (20 per cent). The nearest planets, Mars and Venus, have carbon dioxide around 95 per cent and oxygen less than 0.2 per cent. So the Earth's atmosphere is composed of a most unstable set of gases, far removed from normal chemical equilibrium. This unstable mix has two characteristics needed to maintain life: temperature control, so liquid water is available and biochemical reactions proceed at the correct rates; and oxygen as a source of chemical energy for animals, including humans.
The original high concentrations of carbon dioxide have been vastly reduced by life processes, which have produced the present oxygen-rich and controlled- temperature atmosphere. Our life is now only possible because carbon has been extracted from the atmosphere, to be stored out of the way underground.
Therefore the ecologically correct place for carbon is underground. We are going against the principles of life when we remove carbon from underground and place it in the atmosphere, as when carbon dioxide is produced from the combustion of fossil fuels.
This ecological understanding also gives us the way to substitute for fossil fuels, and likewise for radioactive fuels also best left underground. Sustainable life depends on solar energy producing oxygen from plants. Learning from this, the political challenge today is to replace fossil fuels with renewable energy. Every kilowatt hour of renewable energy used from the sun, wind, water, crops etc, allows about 1kg of fossil fuel to remain underground. There is abundant solar energy for the total abatement of fossil fuel, and the technologies are known and demonstrated. All that is needed is the political will. Hence Kyoto.
Professor of Sustainable Energy Technology
De Montfort University