Green fracking

SIR – Charles Moore points out (Comment, June 2) that the US has reduced its carbon emissions, whereas other countries have increased theirs.

It should be made clear to groups in Britain opposed to shale-gas fracking that not only is the burning of gas less polluting than oil or coal, and requires less energy in its extraction, but gas burning will also provide more energy per unit of carbon dioxide produced. This is mainly a consequence of the differences in chain length of the three sources of hydrocarbons.

By this measure, we calculate that, on average, gas produces over twice the energy of coal and more than 1.5 times that of oil.

Nuclear energy and improved renewables will undoubtedly play a large part in the future; but in the meantime, fracking gas would not only overcome Britain’s dependency on less reliable countries for its energy, but might go a long way towards helping the country to meet its commitments to reduce carbon dioxide emissions.

Dr David Frape Robert C Cook Professor Denis Murphy Editors, World Agriculture Mildenhall, Suffolk