asked the Secretary of State for the Environment what research his Department has conducted to assess the differing environmental implications of internationally agreed policies to (a) freeze production of chlorofluorocarbons production by 25 per cent.

My Department is an active participant in the work of the co-ordinating committee for the ozone layer which is run by the United Nations environment programme. CCOL has been assessing various scenarious for potential ozone depletion by CFCs and other trace gases, and these are also under consideration by the Government's stratospheric ozone research group. A two-dimensional model for testing scenarios, which is being developed in Cambridge, will enable my Department to conduct its own independent assessments.