§ 2.54 p.m.
§ LORD CONESFORDMy Lords, I beg leave to ask the Question which stands in my name on the Order Paper.
§ [The Question was as follows:
§ To ask Her Majesty's Government whether they have studied the published view of Dr. Harold Johnstone of California University, that the products that would be discharged by aircraft flying in the lower stratosphre could through their chemical effects dangerously change the upper atmosphere that now filters ultraviolet radiation from the sun and thus protects life on earth; and whether, on the best scientific advice available to them, they accept or reject this view.]
§ LORD DENHAMMy Lords, Dr. Johnstone's report, which considered the effect of nitrogen oxides from supersonic transports' exhaust, has been examined in the light of similar analyses made in this country, and taking account of the known composition of Concorde's engine exhaust. Our studies indicate that the effect of operating even a large fleet of Concorde aircraft will be less than the range of normal changes from natural variations, and will not lead to the harmful effects suggested by Dr. Johnstone.
§ LORD CONESFORDMy Lords, may I thank my noble friend for that Answer, and ask him two questions? Am I correct in understanding that, while the Government's scientific advisers think that Dr. Johnstone's figures are probably incorrect, they do not deny that exhaust emissions of aeroplanes flying in the stratosphere could produce chemical changes of the kind described in his paper? Secondly, do those scientists agree that, in that case, the exhaust emissions of very few aeroplanes could start a chain reaction that would be irreversible and could destroy the life of man, beast and plant on this planet?
§ LORD DENHAMMy Lords, in answer to my noble friend's first supplementary question, Her Majesty's Government agree that the exhausts cause the chemical changes; but they are very much less than the calculations of Dr. Johnstone suggest. There are a number of reasons for this. First, Dr. Johnstone based his figures on a high rate of nitrous oxide emission—a higher rate than one would expect from Concorde. Secondly, supersonic transports of the Concorde type fly very much lower than the type of aircraft on which Dr. Johnstone based his calculations. Thirdly, Dr. Johnstone's 155 study does not conform in a number of respects with similar studies made by scientists in the United States and elsewhere. In answer to the second supplementary question asked by my noble friend, there would not be a chain reaction because the natural reconstitution of ozone that takes place in the ozone layer would be higher than the destruction of ozone that would be caused by the amount of nitrous oxides that is liable to go into circulation.
§ LORD CONESFORDMy Lords, may I thank my noble friend very much for that answer? Is he aware that I did not mention Concorde in my Question from beginning to end; and if Concorde does not propose to fly so high, it may be that other aeroplanes do? Is it a fact that the Government's scientific advisers have warned them that if such an emission took place higher than the height at which the Concorde proposes to fly it could start a chain reaction, with the results that I have mentioned?
§ LORD DENHAMMy Lords, the only two aircraft that seem to be anywhere near ready are Concorde and the Russian aircraft, and neither of these flies as high. Their ceiling is about 10,000 feet lower than the sort of aircraft on which Dr. Johnstone based his studies.
§ LORD HARVEY OF PRESTBURYMy Lords, will my noble friend try to convey his interpretation of this question to the United States, bearing in mind that when the Concorde is successful many steps will be taken in the United States to try to keep it out of the country?
§ LORD DENHAMMy Lords, Professor London, of the United States, prepared a report for the United States Administration, and the figures produced in that report were much the same as our own.
§ LORD BESWICKMy Lords, while agreeing with the noble Lord. Lord Conesford, that we have to treat all these matters very seriously, may I ask the Minister whether he will take into account, at the same time as he is considering these matters, the considered view of a panel of experts from the Royal Society, who said:
It is dangerous for trains to exceed 30 miles an hour because the air will enter the 156 compartments and passengers will be suffocated"?That was in 1825.
§ LORD DENHAMMy Lords, I am most grateful to the noble Lord.
§ LORD DOUGLAS OF BARLOCHMy Lords, assuming that it is correct that the variations in the atmosphere will not exceed those which occur naturally, is it not still the case that the variations due to emissions from aircraft will all be in one direction and will therefore be cumulative, whereas ordinary variations in the atmosphere are in both directions and are not cumulative?
§ LORD DENHAMMy Lords, I understand that the nitrous oxides coming from the aircraft will not make any noticeable difference to the variations that are there naturally.