Ozone Layer

HC Deb 04 March 1992 vol 205 cc413-24

Motion made, and Question proposed, That this House do now adjourn.—[Mr. Patnick.]

9.39 pm

Mr. Tam Dalyell (Linlithgow)

In the 30 years since I was elected in May 1962, I have had 37 Adjournment debates ranging from Lockerbie to the rain forest, from kidney transplants to unemployment in the then mining villages of Blackridge, Fauldhouse and Stoneyburn which, in 1963, stood at an unacceptable 5.5 per cent. Yet in all that time no topic has approached in importance the plant pathology and skin cancer threat of an ozone hole.

The stakes are mind-boggling. The issues, as the Secretary of State for the Environment was reported to have said in New York earlier in the week, are dramatic for humankind. If some of the more alarmist views are half correct, it could mean that we could go the way of dinosaurus and pterodactyl, and it would be curtains for human life.

However, I am not alarmist. One of the saltier scientists with whom I talked said that, in the short term, if a person spent March and April in the nude in Scotland he would be safer than if he sunbathed on one day at high noon in Malta. That is the view that I take in the short term. In the medium and longer term it may be a different story. In general, I am concerned about the year 2000, 2005 and 2010. By his nodding of the head I think that the Minister assents to that general view.

My application for an Adjournment debate was prompted first of all by the recent NASA public statements, which may, incidentally, have been prompted in turn by internal problems in the NASA set-up and, secondly, by the widely reported statements of Greenpeace.

For example, at the top of page one of The Scotsman on 14 February, over the byline of its justifiably respected environment correspondent, Auslan Cramb, my concerned constituents were told:

Pollution map points way to ozone hole over Scotland. That appeared on the front page of a quality newspaper. He went on to say: A new map of atmospheric pollution has for the first time given a dramatic early warning of possible ozone destruction above Scotland. It shows exceptionally high levels of the main ozone-depleting chemical—chlorine monoxide—over Scotland, Scandinavia and Russia, with the highest concentrations above Shetland and the west of Norway. Scientists have given warning that the pollution, caused by man-made chemicals, could herald the creation of an ozone hole similar to the one which appears over the Antarctic every spring. The next few weeks will be critical as increasing sunshine in the northern hemisphere encourages the reactions which can destroy the life saving layer. That is strong stuff, and it is no wonder I came rushing down hoping to put a private notice question, so concerned were my constituents. That article continued: Ozone protects the planet from cancer-causing ultraviolet radiation, and health specialists say a 10 per cent. decrease in ozone levels could lead to 300,000 extra skin cancers and up to 1.75 million extra eye cataracts each year. The possibility of an ozone hole above highly-populated areas was revealed last week by scientists in Europe and America. What are the people affected to make of that? The article adds: The latest graphic representation of the findings, showing the highest concentrations of C10 in yellow and orange, was produced for Heriot-Watt. Dr. Robert Harwood, of Edinburgh University's department of meteorology, stressed that concentrations of C10 would vary, and its presence was not a guarantee that ozone-thinning would take place. That is alarming enough.

Those of us concerned with the environment are delighted that Geoffrey Lean of The Observer has made a marvellous and miraculous recovery and is returned to health, and he showed enormous courage in doing so. He wrote under the headline Fears over the ozone layer spur action on treaty the following report: The studies predict that harvests in the US and the former Soviet Union will be decimated as the greenhouse effect takes hold. Food exports from the US, which help to feed 100 nations, could fall catastrophically. The African savannahs, home to 200 million people, would dry out to resemble the Sahel. That also is alarming stuff, yet with the experience of having written on a weekly basis for New Scientist for more than a quarter of a century, I must tell the Minister that Mr. Chris Rose and his colleagues at Greenpeace have produced serious work that deserves serious and detailed Government reply.

Greenpeace knows that I am the public friend of the nuclear power companies, of British Nuclear Fuels and, heaven help me, of Nirex—and do not always share Greenpeace's opinions. Rather than repeat everything that they said, and although I am fortunate to have a little extra time, I shall truncate their remarks. However, I asked Mr. Chris Rose to submit his material to Dr. Alan Apling of the Department of the Environment and to the Minister's other advisers. I also gave notice to the Minister of other authorities that I consulted in preparation for this Adjournment debate and before formulating my questions.

Those to whom I spoke included Professor Tom Blundell, FRS. director of Agricultural and Food Research Council: Professor John Dale, professor of botany at Edinburgh university, dean of the faculty of biological sciences-I should say I am a member of the university's biological sciences advisory committee; Dr. Joe Farman of Cambridge, who first identified the ozone hole above the Antarctic; Professor John Knill and his colleagues at the Natural Environment Research Council; Sir John Mason, a distinguished cloud physicist who was the former head of the Meteorological Office; Dr. Paul Rogers of Bradford university, and expert of NASA and a plant pathologist by training; and Dr. David Royle of Long Ashton research centre. I received valuable briefs from the House of Commons Library science section, and from the Labour party.

I just have time to make brief reference to the Greenpeace brief that was sent to the Department. It states: We are pressing for a complete and immediate ban on ozone depleting substances and will continue to do so in the run up to the March 23 formal EC Environment Ministers meeting. Germany has reiterated its intention to go further than the EC informal agreement (of a 100 per cent. phase out by the end of 1995) and intends to phase out all CFCs in 1993. There is no legal obstacle to Britain doing the same (it is allowed under Article 130 of the Single European Act). Greenpeace believes that the results from NASA, and from the European Arctic stratospheric ozone experiment, show that severe ozone depletion, possibly resulting in the creation of an ozone hole could occur over parts of the northern hemisphere—including Britain—in the next few weeks or months. Preliminary NASA results released on 3 February show that the development of a late winter or spring ozone hole is increasingly likely. The reason is that CFCs and other chlorine-containing chemicals have reached the stratosphere and have been broken down to chlorine monoxide, with halons being broken down to create bromine monoxides. NASA has found 1.5 parts per billion of chlorine monoxide over eastern Canada and northern New England—a higher level than has ever before been recorded over the north or south polar regions.

Data have also indicated a lessening of the atmosphere's predicted ability to recover from periods of ozone depletion. The likelihood of significant volcanic ozone loss over the northern hemisphere, now and in the future, is greatly increased by the presence of large quantities of natural volcanic particles in the lower stratosphere, which effectively lock up oxides of nitrogen that would otherwise combine with reactive chlorine before it is involved in the reactions that lead to ozone destruction.

An increase in the number of sulphuric acid particles, which act in that way, is the result of a tenfold increase in stratospheric aerosol created by the Mount Pinatubo volcanic eruption. That eruption has affected the likely timing and severity of ozone depletion, but it would not cause that without the chlorine and bromine pollution.

The chemicals that contribute to the pollution include CFCs, carbon tetrachloride, HCFCs, methyl chloroform and halons. In the United Kingdom, ICI is the largest manufacturer of those chemicals. It has announced the closure of its CFC 11 and CFC 12 plants from early 1993, but it then intends to import CFCs from the Dutch chemical company Akzo.

The Department has received the rest—and, indeed, the summary—of the hard work done by Greenpeace. Let me add that, according to the opening leader in New Scientist on 15 February—written by an extremely responsible and knowledgeable man— New Scientist does not always see eye to eye with Greenpeace, but it happens that when Greenpeace calls for a ban on the production of all substances that deplete ozone, it is talking sound scientific common sense. The Prime Minister should not instinctively reject its proposals. Having received notice, will the Government tell me their reaction to the work of Greenpeace?

The Scotsman says: Springtime is the danger period in both northern and southern hemispheres, when sunshine arrives after a long dark winter, causing the perfect conditions for ozone destruction by chemical reaction. The ozone overhead in Europe during this month and next month is already 8 per cent. less than it was a decade ago. Tackling the problem is not so much a political opportunity, but a life-saving opportunity, and the Government should act now. It will give scientists and environmentalists no satisfaction to say I told you so. In a week's time the satellite which suggested the ozone layer above Britain was primed for destruction, will face the northern hemisphere again. What it then reveals should be irrelevant. The need for drastic action has been proven. My distilled view is that we are not dealing with an ecological time-bomb that is likely to go off in 1992 or 1993, but by 2005, the situation could be horrendous. However, because it will get worse before it gets better, we have a five to 10-year lag time. The questions that I ask are therefore urgent and really for the here and now. The hon. Member for Rochford (Dr. Clark), who is Chairman of the Select Committee on Energy and a knowledgeable chemist, knows that there are such things as lag times. I see that he assents to that general view.

The chief danger may not be human beings but the effect on crops. I understand that there is a possibility of ultra-violet damage to crops, especially seedlings. DNA absorbs strongly in ultra-violet, which causes chromosome breakages and mutations in higher plants, and that is proportional to dose. The suggestion is that natural levels of ultra violet, for example in polar regions and the tropics, may affect species distribution favouring those with a low nuclear DNA content.

If that hypothesis is correct, increases in ultra-violet may have long-term effects on ecosystems leading to the exclusion of species with high nuclear DNAs. Some evidence suggests that ultra violet can damage chloroplast DNA, the extra-nuclear genetic machinery present in green cells. This may lead to abnormalities in photosynthetic machinery and loss of yield, quite apart from any other effects through the nuclear genetic mechanism.

The susceptibility of seedlings to ultra violet varies with species. Most experimental work is done with young seedlings, because they grow quickly, in a limited range of crop plants. More work must be done, particularly in relation to flavonoid synthesis. On exposure to high levels of ultra violet, many plants produce large amounts of flavonoid pigments, which absorb ultra violet and thus minimise damage elsewhere in the cell. Quite a lot is known about the biochemistry of the effects, and ultra violet appears to increase transcription rates of genes involved in flavonoid synthesis.

There are common features of the biosynthetic pathways leading to flavonoid production and to production of anti-fungal compounds and phytoalexins, which are produced on exposure to fungal attack. I do not know—nor do those with whom I have talked—and I have been unable to find out whether exposure to ultra violet, thus stimulating the flavonoid pathway, also confers anti-fungal resistance by stimulating that part of the route common to phytoalexin synthesis. Plants weakened by ultra violet damage may be more liable to fungal bacterial attack nevertheless.

There is a desperate need for research in this field. I understand that researchers led by Dr. David Royle and Dr. Keith Brent at Long Ashton and by Peter Ayres at Lancaster are applying for a number of grants and help in dealing with this situation.

The Library of the House has produced some excellent material on the consequences for plants of ozone depletion. Dr. Ann Davies of the Library has written on that subject and the information will be available to the Department. I found it extremely convincing.

On 25 February, I asked the Ministry of Agriculture, Fisheries and Food what assessment the departmental plant pathologists had made of the results for agriculture of changes in the ozone layer. The Under-Secretary replied: Against the background of the Department of the Environment's continuing programme of work on the effects of ozone depletion on plants, this Department is considering advertising for a research proposal on this matter. Why do not the Government agree at once—

It being Ten o'clock, the motion for the Adjournment of the House lapsed, without Question put.

Motion made, and Question proposed. That this House do now adjourn.—[Mr. Kirkhope.]

Mr. Dalyell

Why do not the Government agree at once to back the proposal of the Agricultural and Food Research Council from Long Ashton and Lancaster about the effect of climatic changes on plant diseases, especially in relation to ultra-violet radiation and moisture within the biological adaptation to global and environmental change programme?

I shall ask questions of which I have given notice. What information does the Minister have on the ozone-depletion studies being conducted by United Kingdom scientists at Kiruna in Sweden? What is the current and predicted depletion of the ozone layer this season? What is the percentage increase in ultra violet reaching the surface, and what data are the United Kingdom getting from the National Aeronautics and Space Administration on ozone depletion and ultra violet increase?

I commend to the Department an article by Dr. John Pyle which 1 know that it has read. I ask about the European Arctic stratosphere ozone experiment which has a better understanding of stratospheric ozone and how it is destroyed around the Arctic. Dr. Pyle ends his study by saying: While the experiments end in March next year, that is not the end of the project. Analysis of the data will continue for months and in some cases for years afterwards. The experiments will provide new data that should reveal valuable and exciting information about the processes controlling the evolution of the low stratosphere. It will he a period of sustained concerted effort to monitor all the processes contributing to ozone loss in the northern hemisphere. The scientists involved hope for many advances from this innovative combination of data, experiment and theory. By its very nature the project already marks a significant success, the coming together of the European atmospheric scientists in an endeavour in which national and European Community funds have been pooled to build an enterprise well beyond the work of a single country. There was a good deal of argument in the House yesterday about diversification of defence. There is a crying need for resources at the very limits of technology to do the work of the kind Dr. Pyle mentions, which, at the end of the day, may protect us all.

I draw to the Government's attention the Greenpeace note on ozone depletion over Sweden. Do they think that there are any inaccuracies in it?

What is the effect of ultra-violet on phytoplankton, and to what depth does it have an effect? That is a very important question in the view of Sir John Mason.

I refer to the letter of 3 March from Secretary of State for Scotland in which he said: We do however share your concern which is why we have asked the advisory group, the Committee on medical aspects of radiation, to consider the implications for health. I have given notice to the Department that I should like a comment on the work of that organisation.

Mr. Bob Cryer (Bradford, South)

I congratulate my hon. Friend the Member for Linlithgow (Mr. Dalyell) on initiating the debate. The subject has been a matter of concern for many Members of the House, and has been the subject of two well supported early-day motions. Will my hon. Friend also say that it should be a matter for concern to the Government that in 1990 this country exported about 40,000 tonnes of CFCs, and that an earnest of Government concern would be an attempt to persuade exporters to curtail those exports rapidly and completely?

Mr. Dalyell

My hon. Friend is one of those Members who knows how best to use the considerable, expert and scholarly resources of the Library. He may like to read the briefs that have been prepared for me by Christopher Barclay and Nicola Donlon. In my view that is excellent work, which would go some way towards providing a serious answer to my hon. Friend's question.

What are the Government doing about sheer basic information to prevent the likelihood of cancers—simple advice such as saying, "If you must sunbathe, do so after three o'clock when the sun is lowering, rather than when the sun is high in the sky"?

In an excellent study in The Bandar times this week. Sean Ryan, its environment correspondent, wrote: 'Politicians say the right thing, but they never seem to get around to committing themselves to doing it … in 1985 … we reported the ozone hole. It was obvious there was a problem then but seven years later people are still arguing about whether it's necessarry to do anything'. Only time will tell who is right. The figures for the occurrence of skin cancer appear in a written answer to a question asked by my hon. Friend the Member for Newcastle upon Tyne, Central (Mr. Cousins) at column 582 of Hansard of 27 February. I refer the Minister to what his colleague, the Under-Secretary of State for Health, told the House there.

Do the Government agree that there is no long-term future for CFC substitutes? What is their policy for recycling, and will they have proposals for the Copenhagen conference in November—whichever Government represent us there? What is the Government's commitment to getting rid of halo-carbons?

In that context it is vital to support the work of the Agricultural and Food Research Council. A year ago I went to Rothamsted, and was the guest of Professor Lewis and his colleagues. Professor Lewis has written a powerful letter to Professor Blundell, which is available to the Department, as is the work being done at Long Ashton, just outside Bristol. Some fairly quick decisions are wanted.

For example, some of the work being done is to determine the ranges of tolerance to key climatic variables of pathogen parameters important in determining epidemic development, especially the effects of ultra-violet light and moisture—in order to contribute to our understanding the effects of climatic change on the occurrence of fungal plant diseases. Incidentally, the fungal aspects are enormously important, as the hon. Member for Rochford, the Chairman of the Select Committee on Energy knows.

Finally, why have the Government not yet paid their cheque for the Montreal convention, and why have they not pressurised our European partners to ratify the protocol?

My good fortune in having a little more time that I expected has enabled me to give just a taste of the kind of evidence now emerging. I am glad that the Minister now has 22 minutes in which to reply, because more people will be interested in what the Government are doing, and in what the Department is thinking, than in what I have to say on the matter.

10.9 pm

The Parliamentary Under-Secretary of State for the Environment (Mr. Tony Baldry)

The whole House will be grateful to the hon. Member for Linlithgow (Mr. Dalyell) for raising this important topic. It is a complex topic which requires a degree of intellectual honesty, and which requires us all to rely on the best science and to have regard to principles such as the precautionary principle. The hon. Gentleman has raised the issue with his usual courtesy and with his usual thoroughness.

The threat of stratospheric ozone depletion and the potential impacts that that might have on human life and on the environment have been of concern to the Government since the negotiations leading to the Vienna convention for the protection of the ozone layer in 1985. Throughout the period, United Kingdom scientists have made major contributions to unravelling the complexities of ozone depletion. The Government have played a full and often leading role in developing the Montreal protocol on substances that deplete the ozone layer, restricting and eventually phasing out the production of ozone-depleting chemicals.

We have made a payment of United States $1 million towards the Montreal protocol. That represents the United Kingdom contribution towards work programmes already agreed. We remain fully committed to meeting our obligations to the interim multilateral fund as agreed in June 1990, but it will be difficult for us to make future payments unless the fund starts forecasting future disbursements and receipts to give donors confidence that it is not building up excessive cash balances. We believe that contributions to the fund should match as closely as possible expected annual disbursements against work programmes and should not be required as arbitrary divisions of the total. Good, realistic financial planning and credible assurances that successive cash balances will not be built up are required and are routinely provided by other funding agencies such as the World bank.

We are determined to meet all our obligations to the Montreal protocol. We have taken a leading part in the work of the Montreal protocol.

Mr. Dalyell

Will the Minister clarify the question of subscriptions to the protocol?

Mr. Baldry

With respect, that is the point with which I have been dealing for the past three minutes. I am happy to repeat my comments, but I suspect that, if the hon. Gentleman reads Hansard tomorrow, he will see that I have dealt with the matter at some length.

United Kingdom industry has also contributed by voluntarily limiting the use of ozone-depleting chemicals, taking a leading role in the development of substitutes and planning to phase out the production of the principal components ahead of the Montreal protocol requirements.

In recent weeks, considerable confusion and anxiety have arisen among the general public about the possibility of health risks from increased ultra-violet radiation as a result of ozone depletion. The hon. Gentleman is absolutely right to draw the House's attention to that concern. I will try to answer the concerns, some of which are largely based on misunderstanding, with the hon. Gentleman's other important points.

First, it may help if I summarise the facts as we know them about stratospheric ozone depletion. I will take particular care to differentiate between general ozone layer depletion and the special conditions that apply over the polar regions.

Only in the past year or two has painstaking analysis of satellite and ground-based measurements given clear evidence of general ozone layer depletion. In the mid-latitudes of both northern and southern hemispheres, including the latitudes of the British Isles and Northern Europe, total column ozone appears to have decreased at a rate of about 4 per cent. to 6 per cent. per decade over the past 12 years. The depletion is higher in late winter and spring than in summer. Total ozone layer reductions since measurements began in the 1950s could be up to 8 per cent. in those latitudes. There still seems to be very little depletion over equatorial regions.

The so-called ozone hole which now appears over south polar regions between September and December each year was much more easy to detect than general ozone depletion. It was the first measured stratospheric ozone depletion to be linked directly with chlorine and bromine containing chemicals released into the atmosphere from human activities. It has appeared every year since it was first reported by Dr. Joe Farman and his colleagues of the British Antarctic Survey in 1985. The depletion in 1991 was as deep and extensive as any seen in previous years, with total ozone over Antarctica being some 60 per cent. less than the pre-1970 levels.

The key to these dramatic Antarctic springtime ozone reductions is a combination of chlorines and bromine-containing chemicals and special meteorological conditions. Ice crystals that form in polar stratospheric clouds under the intensely cold conditions of the southern polar winter provide surfaces for chemical reactions which multiply the ozone-depleting effect of chlorines and bromine-containing chemicals. These reactions are triggered as the sun returns in the austral spring.

An ozone hole has not been observed over northern polar regions. There are some obvious arguments why this should be so. In the southern hemisphere, winds are relatively free to circulate, building up a vortex of intensely cold, isolated air during the Antarctic winter which is ideal for the formation of polar stratospheric clouds and development of the chemistry which precedes ozone depletion. In the northern hemisphere, the abundant land masses interfere with wind circulation and the winter arctic air mass is neither as cold nor as isolated as the Antarctic vortex.

Nevertheless, as levels of chlorine and bromine chemicals in the stratosphere are bound to increase for some years to come, irrespective of international actions taken on controlling production, there is concern that enhanced Arctic ozone depletion may eventually develop driven by the concentration of ozone-depleting chemicals.

Mr. Dalyell

The Minister uses the word "eventually". Is any timespan tagged to that? Incidentally, I welcome the presence of the Minister for the Environment and Countryside, who takes the matter extremely seriously and went to Estoril some 10 days ago.

Mr. Baldry

We cannot predict with any certainty. In several areas, one relies throughout on the precautionary principle, of which I shall say more in a moment. Indeed, the presence of my hon. Friend the Minister for the Environment and Countryside and the comments made by my right hon. Friend the Secretary of State for the Environment, to which the hon. Gentleman referred earlier, demonstrate that the whole Government take the matter seriously. Indeed, that is why I welcome the opportunity of this Adjournment debate to ensure that some of these matters can be recorded in Hansard for everyone to see.

It might be helpful if I were to give some indication of the present Arctic research campaign. This winter and spring, an intensive study of the Arctic atmosphere is being carried out by the European Arctic stratospheric ozone experiment. The experiment involves more than 250 scientists from 17 EC and EFTA countries. The key management role is being played from Kiruna in northern Sweden by the European Ozone Research Coordination Unit, directed by Dr. John Pyle and funded by the Department of the Environment and the European Community. It is fortunate that measurements are also currently being made from the new United States upper atmosphere research satellite launched last September and the United States airborne Arctic campaign. The three experiments complement each other and there is good collaboration between the teams of scientists involved.

The Arctic experiment is an exciting one. We hope that it will add substantially to our understanding of the scientific details of ozone-depleting chemistry and lead directly to improved predictions of future ozone depletion, about which I will say more later.

Unfortunately, early results from the study have been widely misinterpreted. There was genuine misunderstanding on the part of various commentators. That has led to recommendations for people to take unnecessary precautionary measures and to considerable anxiety among the general public. The hon. Gentleman made reference to certain articles in national newspapers which had exacerbated those anxieties.

The problem began in early February, when United States and European scientists announced the first results of the Arctic campaigns. Those results showed that, largely as expected, the chemistry of the Arctic stratosphere exhibited all the classic ingredients now well known from Antarctic studies that lead to enhanced ozone depletion, provided that polar stratospheric clouds are formed in sufficient quantities to provide the essential reacting surfaces.

An additional complicating fact this year is the presence of particulate matter injected into the stratosphere by the eruption of the mount Pinatubo volcano which might provide an additional source of reacting surfaces for ozone-depleting reactions.

Those reports were unfortunately misinterpreted as announcing actual or imminent ozone-holes of Antarctic proportions over the northern hemisphere. The misinterpretations have in turn led to calls for ultra-violet radiation forecasts and health warnings, arousing considerable but unnecessary general anxiety.

Let me say very clearly now, that there is no Arctic ozone hole and no indication of severe ozone depletion over Britain. That has been forcibly pointed out by Dr. Joe Farman, the discoverer of the Antarctic ozone hole, in the national press last week, when he emphasised that ozone levels over Britain were still within the range of natural variability at this time of year.

Mr. Dalyell

I have also talked to Joe Farman. Does the Minister accept that he is concerned about the years 2000, 2005 and 2010, and, whereas that is probably true in the immediate future, we had better not be complacent, had we?

Mr. Baldry

Nothing that I have said has been complacent. If the hon. Member gives me a chance, I shall get to the future. He asked a large number of questions, all of which I am endeavouring to answer, but they are complex and it is obviously important to get the science right.

The scientists studying the Arctic stratosphere are in constant, direct contact with Governments. They report that the perturbed chemistry that they have observed has not progressed to extensive enhanced ozone depletion of the kind seen in Antarctica. The ozone depletion that was observed in January and early February appears to have been broadly consistent with the rate of general ozone depletion of some 4 to 6 per cent. per decade in northern mid-latitudes.

Continuous measurements of ultra-violet radiation made in the United Kingdom by the National Radiological Protection Board on a routine basis, and research measurements made as part of the Department of the Environment's research programme show no evidence of being significantly higher than the normal range for this time of year. I have our results for Lerwick for 3 March, which at 324 Dobson units are well within the seasonal norm. Any sudden apparent increase outside the norm would immediately be notified.

The claims of possible danger to human health amongst people going about their normal business in the United Kingdom at this time of year are totally unjustifed, and I believe we need to get the risks of ozone depletion back into perspective.

There is no doubt that, all other things being equal, less stratospheric ozone means that more ultra-violet B radiation from the sun will reach ground level. Exposure to UVB is associated with a variety of human health problems. However, human beings are naturally subject, and voluntarily subject themselves, to a range of exposure which is much greater than any yet implied or expected due to ozone layer depletion. Even assuming clear sky conditions, UVB radiation levels in Britain are some twentyfold greater during the summer than in the winter simply because the sun is more directly overhead in the summer. Also in the summer, UVB levels in popular holiday areas at lower latitudes, like Spain—the hon. Gentleman mentioned Malta— are more than double what they are in southern England. We increase our exposure during the summer, and particularly while on holiday.

The Government are of course concerned at the significant increase of skin cancer, both in the United Kingdom population and in other countries, that has occurred in the past 10 years. The suspect factor is thought to be sunbathing, and the increased opportunities for sunbathing that modern travel and technology afford. The important point to bear in mind is that everyone should take care in the sun. Existing advice issued by the Health Education Authority about minimising exposure to sunlight should be observed.

In that context, a small increment due to ozone depletion on the already low levels of UVB that we receive at this time of year is insignificant.

However, coming to the question which the hon. Gentleman just raised, if that is the position, what is the concern? Is it at all justified? I believe that it is for four reasons. First, the concentrations of ozone-depleting chemicals in the stratosphere are bound to continue to rise for the next 10 years or so. This will remain true even if we are successful in advancing production phase-out dates for ozone-depletion chemicals when the parties to the Montreal protocol meet in November this year. We shall certainly take a full part in those discussions.

Secondly, we cannot yet predict with confidence how the increased ozone-depleting chemical levels will affect stratospheric ozone. Present predictive models only partially explain polar ozone depletion, and under-predict by a factor of about two the general ozone depletion now thought to have occurred in mid-latitudes.

Thirdly, while the present concerns over increased exposure in the United Kingdom as a result of ozone depletion at this time of the year are unfounded, in global terms there are data to indicate that skin cancers, cataracts and other eye problems and immune suppression would become more prevalent if ozone depletion continued, particularly if it extended towards the currently unaffected tropical regions.

Finally, the research base on effects on plants and natural ecosystems is far from well developed. There is some scientific consensus that increased UVB might overall tend to depress crop production yields, but precise estimates are difficult given the myriad other factors which affect the performance of agricultural crops. Similar arguments apply to natural ecosystems, including the oceans and phytoplankton, the basis of the ocean food chain.

There is considerable research in hand around the world, and within the United Kingdom science base, particularly the research programmes of the Natural Environment Research Council and the research programmes of the Ministry of Agriculture, Fisheries and Food and the Department of the Environment. The general areas for concern are well identified and have been summarised in the recent impact assessment carried out under the Montreal protocol. The active interest and co-operation in this area is well illustrated by the session on ozone depletion and UVB effects being held in April this year at the Lancaster meeting of the Society for Experimental Biology, which the DOE is supporting.

The study of UVB impacts on plants and ecosystems is particularly difficult, because laboratory results are not easily extrapolated to the real world.

Mr. Dalyell

That is true.

Mr. Baldry

I am glad that the hon. Gentleman acknowledges the correctness of that.

The research into this matter involves some difficult areas of science. Other factors such as competition between species and pathogens and nutrient supply may well dominate. Results are being obtained steadily. I will, for example, be particularly interested to hear from our specialists an evaluation of the studies of impacts on Antarctic plankton reported by scientists from the university of California last month. However, we must expect progress towards confident quantitative predictions of effects to be slow in this difficult area of research.

I hope that it is clear from what I have said that the Government are greatly concerned about the possible effects of ozone depletion. Misleading and unwarranted scares about health impacts in the United Kingdom in winter are not helpful in developing a better appreciation of the real problems on which much further work needs to be done. There is no element about which we are complacent.

Action on controlling ozone-depleting substances does not depend on more research on either the science or effects of ozone depletion. Last December, we proposed that the European Community should support an earlier phase out of ozone-depleting substances when the Montreal protocol is reviewed this year. The Community will decide its position this month and the Government will be urging other member states to support the toughest possible measures.

The hon. Gentleman said that other member states seem to be taking tougher measures than we are. I suppose that the member state that is most frequently mentioned is Germany, which, in common with us, is a producer of CFCs and has a law for phase-out in individual sectors. Its law is extremely complex and it has many exemption clauses. Germany's position on phasing out CFCs by the end of 1993 is far from clear. Officials from my Department attended a major conference on CFCs in Berlin as recently as 24 to 26 February, at which German industry representatives and the German Government, including the Minister for the Environment, Dr. Klaus Topfer, were present in force. However, no mention was made at any stage of a 1993 phase-out.

The United Kingdom is committed to phasing out CFCs, carbon tetrachloride and others by the end of 1995 at the latest and halons by the end of 1994. Both United Kingdom producers have stated that they will cease production of those chemicals no later than the end of 1995. My hon. Friend the Minister of State proposed to the European Community Environmental Council in December that the protocol's phase-out dates be brought forward to the end of 1994 for halons and the end of 1995 for CFCs, carbon tetrachloride and tricholoroethane methyl chloroform.

It has often been asked why we do not ban CFCs straightaway. An immediate ban would not be practicable for a number of applications. For example, medical aerosols such as asthma inhalers still use CFCs: they cannot use recycled materials. We are determined to phase them out as soon as it is humanly possible. We are working closely with our EC colleagues and it is important, now that we have a single European market, to achieve that aim.

The depletions in stratospheric ozone that has so far been detected, our imperfect understanding of the science, and the evidence so far available on the possible impacts of ozone depletion are sufficient reasons for minimising as far as possible any further build-up of ozone-depleting chemicals in the atmosphere. That is the objective that the Government will pursue as we approach the next review of the Montreal protocol.

Question put and agreed to.

Adjourned accordingly at half-past Ten o'clock.