§ Dr. David ClarkTo ask the Minister of Agriculture, Fisheries and Food if, further to his answer of 27 June,Official Report, column 441, he will give the greenhouse gas equivalents for carbon dioxide, methane and nitrous oxide; and if he will make a statement.
§ Mrs. Virginia BottomleyI have been asked to reply.
Molecule for molecule, the greenhouse warming effect of methane is approximately 27 times that of carbon dioxide and 165 times that of nitrous oxide. Taking account of concentrations in the atmosphere, their current contribution to the greenhouse effect is estimated to be 55 per cent. (carbon dioxide), 14 per cent. (methane) and 8 per cent. (nitrous oxide). The remaining fraction is primarily due to chlorofluorocarbons.