§ Mr. Malcolm BruceTo ask the Secretary of State for the Environment what assessment he has made of the implications for the ozone layer and the greenhouse effect of discharges of gases from landfill sites; and what steps he is taking to mitigate these effects.
§ Mrs. Virginia Bottomley[holding answer 19 July 1989]: From reviews and research work commissioned by the Department, it can be concluded that methane has a secondary stratospheric role, tending to reduce ozone in the upper stratosphere, but to increase it in the lower stratosphere. Methane is a strong greenhouse gas which currently contributes about 14 per cent. globally to the 474W greenhouse effect. Additionally methane contributes to ozone formation in the lower atmosphere which in turn also contributes to the greenhouse effect.
Landfill sites are estimated to contribute about 20 per cent. of total United Kingdom emissions of methane from both natural and manmade sources. Combustion of methane produced carbon dioxide which is much less potent than methane as a greenhouse gas on a molecule-for-molecule basis.
There are 26 schemes already using methane from landfill in operation with another 13 in the offing. In addition the Department is carrying out research on inhibition of methane production and oxidation of methane at landfill sites.
§ Mr. VazTo ask the Secretary of State for the Environment when he will announce the commencement date of the review he is proposing into methane in landfill.
§ Mrs. Virginia Bottomley[holding answer 21 July 1989]: Her Majesty's inspectorate of pollution commenced a review into the extent of methane generation in current and closed landfills on 18 December 1987. The report is expected soon.