Twenty years on and this interview has lost nothing of its relevance, on the contrary. Watson explains how the view took hold that one international scientific assessment was needed so that ozone policy could progress. He openly describes his own efforts in this respect, and how he saw the proper conduct of a scientist in an advisory position. The problem of advocacy appears, how to deal with dissent (including the sceptics), and how dramatic events influenced international negotiations. In many ways the parallels between ozone layer protection and climate change are explored and I still find Watson's comments insights and comments fascinating.
Earlier this week, at the conference Circling the Square at the University of Nottingham, Mike Hulme gave a keynote speech on the role of scientific consensus for climate policy (a video of Mike's talk is available here). Hulme traced the origin of this consensus thinking to remarks made in 1990 by John Houghton, lead editor of the first three IPCC reports. My interview with Bob Watson shows how the emphasis on scientific consensus can be traced even further back, as it had been developed in the case of ozone science and politics.
Interview with Dr. Robert Watson, White House Office for Science and Technology Policy
Q: When did you come to the field and when did you think about regulation of CFCs?
A: My graduate work in England, by sheer luck, was on chlorine, bromine and fluorine, and how the radicals such as ClO and BrO reacted with themselves and with other species such as oxygen atoms and nitric oxide. So much of the work that I did for totally academic reasons in England turned out to be very useful and central to the theoretical modelling and in understanding the chemistry of the stratosphere. When I went to Berkeley in 1973, Harold Johnston was involved in the whole Supersonic transport issue. That was the first time when I started to get an appreciation of the importance of fundamental science or societal issues, such as the protection of the ozone layer. In 1974 the Molina-Rowland hypothesis came out and at that stage I carried on doing some work that was related to the issue. By 1980, probably the most important thing that I did was to realize that in about two years there was at least six or seven assessments of the state of knowledge. The EC wrote one in the late 70s, NASA, NAS, UNEP, WMO, and the British government. At that stage industry and other people were looking rather at the differences than at the commonalities of the different studies. So I tried to work with the international science community toward a single international assessment. So that there was not a German document, a British document, and an American document. We had some success in 1980 in writing a document; by 1985 we had a document that really was representative of the worldview.
Now when did I first think that we needed regulations? I always kept myself in a situation that some people were not happy with and that is, I very purposely did not comment on whether there should or should not be international regulation. Given that I was chairing the international ozone assessment. My view was for me to take a position personally as a conflict of interests in trying to chair what is going to be a neutral international assessment process. It probably wasn't until the Vienna convention was signed in 1985 when I was asked... I was put in an awkward position in a Senate hearing when Senator Chafee asked me what I thought about regulations. And I answered that there should be at least a global freeze on CFCs and in my opinion a cutback of 20% or so. This wasn't of course a purely scientific decision, it brought in a lot of politics. But to be honest, this was not the first time that I thought about regulation, but in my opinion it was inappropriate for me to have a public position on regulations, given that I was trying to chair a neutral assessment process. The same is happening with climate change, I chair working group 2 of IPCC, that looks at impacts, adaptation and mitigation strategies on climate change. I have some very strong views on climate change, I think it is a very serious issue. But don't believe that I should take a firm position on what exactly the regulation should be, because on that stage I would be perceived not to be neutral chair of the science assessment. So it's a fine line there. When I believe individual scientists should say what they feel about regulations, I feel that when people like myself and Dan Albritton chair an international process, we have to stay policy neutral, otherwise no one is going to trust the answers.
Q: Do you think some of the scientists might have gone too far in a certain period?
A: No, I personally felt that when people like Sherry Rowland were asking for prudent steps and that we needed to attack he CFC issue, I personally had no trouble with them as individual scientists. I did feel that I had not to take a strong position on one side of the coin or the other. I always felt that CFCs were indeed a threat to the ozone layer; there was no question at all about that. The question was exactly: what should those regulations have been? I actually believed that the policy formulation was a fairly logical one. In other words, I felt that we put the Vienna convention in place which had no regulatory aims obviously. The Montreal Protocol came along in 1987 which of course put the freeze in place and a 50% cutback by the year 2000. Then as we further understood the Antarctic ozone hole, we then understood there was a depletion throughout the globe, at least in the Northern hemisphere in winter first, then throughout the global except for the tropics. I thought the progression between scientific understanding and policy response wasn't bad.
Now I know some scientists, such as Sherry, who felt it was very, very slow. And in fact, one had to wait for cause and effect to be established, before policies moved ahead adequately. And I understand that position, and in fact, now I think we have to be very careful on the climate situation, because I think we are in a very similar situation, i.e. we have some theories, suggesting CO2 and other greenhouse gases are going to change climate. But if we wait for cause and effect to be established, because of the long life-time of the gases such as CO2, you won't ever be able to reverse the damage for several decades, centuries and even millennia. So there is this fine line between what level of proof do you need before you have international regulatory action. It's a very tricky one, it could be that we waited too long on the CFC issue. With hindsight, I think it would have been [better] if we'd been a few years ahead in each case of the regulatory actions, now we know what we know, the international process could have moved a bit faster. We would have a safer situation if we would have been a bit more aggressive on the regulations. But there was at least some good relationship between policy formulation and science. It's a trade-off...
Q: You have the Environmental Protection Agency (EPA) in the beginning of the 80s which could not move ahead with their Phase 2 [Phase 1 of CFC regulations was the banning of CFCs in non-essential uses, such as aerosols, enshrined in the Clean Air Act of 1977, R.G.] People give different reasons for that, I wanted to hear yours. One is political, i.e. Reagan was cutting down efforts on this issue, the other is scientific, saying that the models had all steady-state calculations, because production figures were stable. This turned out to be wrong and as soon as models predicted losses again, politics could move ahead.
A: I think four things happened in the early 1980s. One: Reagan got elected and therefore there was number of people that became ‘less sensitive’ to environmental issues such as ozone depletion. There was a complete split inside of EPA. One part of EPA still thought it was a very serious issue and rule-making should have advanced. Another part of EPA did not feel it was important, so even inside EPA, at that point in time, there were two major directors that had a very different views of how serious this issue was. And in fact the issue got transferred from one office to another after a while. Some people got complacent, because emissions were flat. In reality this was a purely artifactual recession, not a mature market, and indeed after we came out of recession, the emissions went up tremendously. Then the models showed the lowest ozone depletion ever. The forth thing, probable the most unfortunate of all, was that industry became complacent. Industry saw two things: the models with low ozone depletion, and no political will to move ahead. Therefore they stopped doing research on substitutes. And that, I think set us back possibly a decade.
Q: Wasn't it the case that substitutes were known long before, it was only a question of economies of scale?
A: I honestly don't know and it would be worth asking some people that are more experts than I am. It could have been economies of scale but we also hadn't done some of the very important toxicological testing. That takes several years to look at chronic exposure issues. That was one of the fatalities of complacency of the 1980s.
Q: Could you describe how the scientific consensus was achieved?
A: Once we stopped having these 5 or 6 international assessments and we went to one, we could at least get everyone together and so the typical assessment would be written by one or two hundred scientists and peer-reviewed by an additional 100 or so scientists. They key was getting people together to discuss their differences. In my opinion, once we got them together, some of the differences almost seemed to disappear. There was indeed a wide range of model results, but there was no question that all models suggested - at least at high altitude, 40km - that if you put chlorine and bromine into the atmosphere, ozone decreases. None of the models produced ozone, they all reduced ozone. There were obviously differences in latitude, distribution of ozone depletion, seasonal variations and things like this, so yes there were some fairly significant differences, but at the same time there were areas of commonality. The field measurements, for example, once we had observed that CFCs were long-lived, that was a very important thing, there was no quick tropospheric loss mechanism, that meant it was a long-term problem. Once we had observed through Jim Anderson, that ClO was in the stratosphere, that again said, boy, now we've actually got the proof that there is the radical that the model predicts destroys ozone. Slowly but surely through the international process the picture got put together. Certain things were robust, as I listed above. And then of course, once we got to the observation of the ozone hole, then it was very controversial, we had three explanations... Once we got the evidence from the ground based station from McMurdo, that stated the point fairly clearly, that it was man-made chlorine and bromine but didn't proof it definitively. Once we had the aircraft campaign from Punt Arenas, there was in 99.9% of the science community view no doubt whatsoever. Once we got such a large perturbation and such wonderful results from aircraft, satellite observations of the extent of the ozone hole, that started to galvanize the community fairly quickly. The voices against the anthropogenic mechanism became very, very low.
The other big debate which occurred in that same time frame: was there evidence of ozone depletion from either the ground based system or the satellite system? And that was extremely contentious for a large number of years. But when we did the international Ozone Trends Panel in 1988/89, that again started to galvanize the community. People like Sherry Rowland were extremely constructive in making sure that we looked at ozone depletion as function of latitude and season rather than global annual average. So over a number of years it went from a very controversial perspective into almost what I call a single viewpoint. It's still that one or two people had different views but largely, again 95% agreed that we had evidence for ozone depletion. The process that made it work was the international process. This was the mechanism to force everyone together to look at the same data at the same time.
Q: This is quite unusual for a scientific controversy to happen.
A: Yes, but it is the only way to go forward. We do it now in climate change and in loss of biological diversity. So the idea to get people together to argue about what we know and what we don't know, where there is a large majority of opinion and where there is a vocal minority, is becoming more and more the tradition now on all of these environmental issues. This doesn't mean that the scientific community has to come up with a single position, but you need one document where the scientists can argue and we can put on a piece of paper what we know and what we don't know. We as a scientific community owe to the policy community that one document, and if there is more than one view, we should show more than one view. If there is a large majority view, we should tell policy makers. I see this as an obvious evolution of science. A lot of people may say this is a major change. Well, maybe it was a major change, but it is a very logical change. The time was right, so to speak. It was a global issue, so there was no use having an American assessment of the science and a German. It may have been unusual but it was the obvious next step.
Q: But it had to be done. It would not have evolved from a national level...
A: It could never evolve, in my opinion, form a national perspective. Also when we went down with the aircraft, we made sure that there were not only American scientists, but European scientists, from the UK, Germany, Norway... When you have a global problem, you have to have international science both in doing and assessing it. Without that the policy makers would be arguing forever. The Americans would take the American position on science and so on, and we would never ever come to an agreement.
Q: So it was crucial that NASA had high prestige and the financial means?
A: It was essential. Through NASA I could assure that there was adequate funds to do the assessment, although most people came with their own money. The German scientists travelled on German government money, the French on French money and so on. We had to pay for some infrastructure. But the important thing was making it non-NASA. A friend of mine, Adrian Tuck, said he couldn't come because he worked for the British government at the time and this was a NASA program, and so I said: what if it was done by WMO? That was fine, it was international. So I got in touch with WMO and the 1981 report was international, a WMO with NASA report. By 1985 I had WMO, UNEP, the German ministry of science and the British department of environment [these reports can be downloaded here, R.G.]. It was no longer just a NASA document. The other very important point was: No one in NASA or any other funding agencies could censor it or review it, it was only reviewed by the scientists that took part in the assessment. It didn't go through a NASA review, it didn't go through a UNEP review, neither through WMO, they were sponsors but had no role in who wrote the document and no role in who peer-reviewed it. They could suggest names, obviously. But as institutions, they didn't have a role. It was almost as free from politics as you can ever get an assessment. And I think that was the key to success.
Q: How important was the discovery of the ozone hole for the Montreal Protocol?
A: For the U.S. government it was irrelevant on paper, that is, we had already decided that we were going to push for the Montreal Protocol with the freeze in 1995 and the 50% cutback by the year 2000. I do believe however, that for the Europeans it was very important. That's a very personal deduction. However, it certainly didn't hurt the U.S. position, those of us in America, that thought there needed to be something like the Montreal Protocol and if the science was good, that gave us further evidence.
Q: Is it true that you had influence on politicians in the EC, showing the charts of the ozone hole?
A: Yes, I think as a chairman of the assessment and coming from NASA with all this data, one could show the data in a very, very vivid way. When you combined what we saw from space with the early ground based observation, it did indeed have an effect. I think the satellite imagery showed you this huge hole developed every spring time in the Southern hemisphere and it was the size of the Antarctic continent. So it had an impact, but I tried to make sure that people recognized that we hadn't proven beyond the shade of a doubt that it was due to human activities. I was very nervous for the following reason. I believed that the Montreal Protocol was necessary even if the Antarctic ozone hole was not due to human activities. My position in America was: you should put your position forward, assuming there was no antarctic ozone hole. I felt there was enough of a global threat that we should have the Montreal Protocol. That was my personal opinion and when asked, I said that was a wise approach. Rather than advocating it. What I was nervous about was the following. If governments had said: the reason for the Montreal Protocol is that the Antarctic ozone hole is due to chlorine and bromine, and it wasn't true, then it would backfire completely. And I knew we had such a wonderful experiment plus the second ground based experiment, Susan Solomon's in Antarctica, that I was fairly convinced that we would come up with far better information. I was surprised how well we verified cause and effect. I hoped we would do that, but the data was wonderful, it was even beyond our wildest dreams in some respects. So I was very cautious and the U.S. position was not based on that. The question was, if it turned out that the Antarctic ozone hole was not due to human activities, what would we still want to do? And my view is the global threat was still large enough to have the Montreal Protocol.
Q: Do you think that the ozone backlash can be connected to this process of galvanizing part of the different disciplines leaving outside those who haven't done important research?
A: I don't understand the backlash because I think the scientific evidence is very, very strong. And some of the arguments they have used just don't hold any water at all, and that's what really puzzles me. Good scientists are saying things that are clearly wrong like CFCs are too heavy... That's ridiculous. Part of it may have to do with the climate issue, which they think is not serious. I think it's very serious...
Q: More serious than the CFC-ozone issue?
A: Yes, I personally believe the climate issue is much more serious, if the models are correct. The long-term effects are more serious and the energy and agricultural policies are more difficult to change than just CFCs. I think some people try to undermine the ozone issue and say we're wrong in order to show that if we're wrong on ozone we're wrong on climate. So I am puzzled; some of the meteorological community is involved in the ozone issue, some but not all of them. Maybe some people just like to be the opposite of the mainstream. But I would have thought they would have picked more logical parts of the puzzle to try and pull apart. But they are using a line of attack that is easy to disprove.
Q: Obviously it is also a right-wing/left-wing battle in a way...
A: Which is very silly. I mean all of us never wanted environmental issues to be like this. What we need is the truth. I'd love to have no environmental issue.
Q: You obviously don't think nature is robust?
A: I am amazed how robust it is. But I believe that with a huge population increase, coupled with major change in industrial practices, more technologies, I think we've put a strain on nature that it has never seen before.
Q: Did you change your opinion in that respect?
A: I look at the CO2 record and the temperature record of the globe over the last 1000 years or so, pre-industrial revolution and it's absolutely flat, CO2 only moves around by that 5ppm, now we have 280ppm. Temperature records for a 1000 years, global average: very, very stable. I am amazed how stable nature is over hundreds and hundreds of years. But now you can see what industrial revolution has done, the atmospheric composition is changing. Nature is robust, the question is: can it resist the onslaught of this huge population with a huge industrial revolution? It is not just population; it is a combination of people and new technologies. I see some robustness there that surprises me. But I also think it is only finitely robust.
Q: Did you think in 1974 that nature was fragile?
A: I think it is clear that you can threaten the ozone layer fairly easily, the climate situation is... there is no ozone record to look back at. I looked at the temperature record like a lot of us have. And as I say: climate has been amazingly constant, but small changes in climate can have fairly significant consequences for society.