Burning CO2 to save the planet

Ken Caldeira and James Kasting of Pennsylvania State University have concluded in Nature magazine that carbon dioxide depletion is likely to end life on Earth - despite recent rising carbon dioxide levels due to the past hundred years of industrialisation - a mere 'blip on the geological landscape'. The trend since life evolved billions of years ago is for carbon dioxide to decrease.

Once carbon dioxide levels fall below a certain threshold, plant photosynthesis on which all life depends, will become increasingly difficult. The planet will become rapidly hotter and water will evaporate into space. Once the water is gone, all life would become impossible. In about a billion years' time, says Tyler Folk, professor of applied science at New York University, 'we can envisage incinerating the white cliffs of Dover in giant solar furnaces and burning off the carbon dioxide in the rocks'.