asked the Secretary of State for Defence what research has taken place into the effect of thermonuclear detonations on the stratosphere; and what were the findings.

Since the partial test ban treaty came into force in 1963 there has been no research on the effect of thermonuclear detonations on the stratosphere by direct experiments.High altitude nuclear tests before 1963 and theoretical studies since indicate that nuclear explosions inject radioactive debris into the stratosphere, produce disturbances