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Oral History Transcript — Dr. Neil Harris

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Interview with Dr. Neil Harris
By Keynyn Brysse
University of Cambridge, UK
March 16, 2009

 
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Neil Harris; March 16, 2009

ABSTRACT: In this interview, Neil Harris discusses topics such as: ozone layer depletion; his background and his studies at the University of California, Irvine under F. S. Rowland; European Ozone Coordinating Unit; stratosphere; Mack McFarland; National Aeronautics and Space Administration (NASA); Antarctica; ultraviolet light absorption; Rumen Bojkov; John Pyle; Bob Watson; National Oceanic and Atmospheric Administration (NOAA); Intergovernmental Panel on Climate Control (IPCC); Peter Bloomfield; chlorofluorocarbons (CFCs); Paul Crutzen; Mario Molina; Dan Albritton; Jim Lovelock; Joe Farman; World Meteorological Organization (WMO); United Nations Environment Programme (UNEP); Montreal Protocol; DuPont Company.

Transcript

Brysse:

Okay. So can we start with a background of any work youíve done involving ozone depletion, which I understand is a lot?

Harris:

Yeah. I did my Ph.D. at UC Irvine with Sherry Rowland, and the work I did was to do ozone trends in the northern latitudes. I then came back to the U.K. in 1990 and have physically worked in the European Ozone Coordinating Unit since then in different capacities. So the work weíve been doing, a lot of that is focused on polar ozone, Arctic ozone in particular, but thereís also been — Iíve done a variety of different research, including maintaining interest in the ozone trend work as well in the polar Antarctica ozone loss.

Brysse:

I have an idea what your Ph.D. was about, but what was it in? Stratospheric chemistry?

Harris:

It was in the Chemistry Department. I have a Ph.D. in chemistry, yeah.

Brysse:

I interviewed Rowland when I was in San Diego a couple of weeks ago, and he told me a little bit about your work and about working together on the Ozone Trends Panel report. So that report was basically your Ph.D., right, expanded a bit in which other people contributed?

Harris:

It was actually the other way around just because of the timing. The report was writtenÖYes, I effectively wrote that, it was then edited by the rest of the chapter the section on the trends from the ground-based stations for that report. That became then the bulk of my thesis.

Brysse:

Oh, thatís good to know. Maybe I misunderstood. In my thought the timing was the other way around. I thought you did your thesis first and then —

Harris:

Well, nowadays it would have to be that way around, yes, just because of publication issues regarding the assessment. But no, I think the report was published after my thesis, but there was a delay in the production, if I remember. So I would have finished my thesisÖI canít remember. But I could check the dates because Iíve always got my thesis. But I remember sort of moving it over into my thesis from the report rather than the other way around, so thatís my memory. But heís got a good memory, soÖ

Brysse:

Rowland told me a bit what itís about, but Iíd like to ask you as well. How did you or he think of doing what you did for your thesis? Where did the idea come from?

Harris:

Iím not sure I can remember that. I mean the general background was — Letís think. I went out during May Ď84, so the end of my first year of graduate courses and stuff would have been around May/June Ď85. The first thing I tried hadnít gotten anywhere, but I canít remember — But the ozone hole paper, if not published, was in the — When was the ozone hole published, May Ď85? [Yes] May Ď85, so that would have come out towards the end of my first year. Iíve forgotten if I started this before or after, but both the modeling studies without any heterogeneous chemistry, and then when the ozone hole paper came out, that was starting to show seasonal cycles in the ozone trends, and no one had looked for seasonal cycles. If youíre looking at mid-latitudes, a) itís a more public interest to look in the northern hemisphere because there are more people, but also there are just better long-term records in the northern hemisphere. So as a result of those two things, the thesis came out. Itís probably largely Sherryís idea, but those were the two things in the background at the time that led to it.

Brysse:

So the idea was to look for seasonal variation.

Harris:

Well no, no. The idea was just to look for trends, and there was only one when I started looking because I anyway looked at the seasonality, and thatís where the pattern starts to come out, which hadnít been apparent in the previous studies which hadnít looked for seasonal trends. But that was all in the background as I started, and as I said, it was probably Sherryís idea and I just looked at one dataset, the Arosa dataset to start with. He probably met Hans Eledoich [?], the Arosa guy, at a meeting. It was probably one of those things. Then I started looking at and saw the seasonal cycle in that, the ozone hole was coming out. Some of the modeling studies were showing quite strong seasonal cycles at 40 kilometers, not at the bottom. So it went on from there, looking at more data other than Arosa.

Brysse:

So I just want to make sure I understand exactly what results you got.

Harris:

Iím much better on the results than the original motivation.

Brysse:

Okay, good. So other studies really hadnít seen a trend in ozone depletion, and that was because they were not looking at seasonal differences; they were averaging the whole year. And they werenít looking at different latitudes; they were averaging all of the latitudes. And I think Rowland also mentioned something about summer months had been weighted more heavily because they were less variable. So all three of those things would mask a trend that was greatest in the winter months, seasonal, and at only high latitudes.

Harris:

Yes. Thatís basically right. I mean that is right. In addition, any earlier study would have had less data, and so the trends become more apparent with time. The work I did showed that they probably should have picked up the signal if they had looked for seasonal trends earlier. It was starting to become evident in the record, but it wasnít as clear as it was by the time I did the calculations. I forgot when I [???], through 1986.

Brysse:

Right. Thatís the data you had went up to 1986?

Harris:

I think in my thesis I did it up to 1986, and some of that was also because a guy called Rumen Bojkov had been going through the data, and so improving the quality of the data a great deal, all throwing out bad data. So overall improvement of the quality of the data.

Brysse:

Thatís with the recalibrations and stuff that are described in the Ozone Trends Panel report?

Harris:

Yes. I think from a technical point of view, the big thing was the weighting point, the technical point was statistical technique will just put much less emphasis on the winter months if you do an annual average. So the minute you try and separate them in whichever way now, because different people do it differently now to how it was done then, youíre going to start to pull that signal out, and if you just took a broad average you wouldnít see it.

Brysse:

Do you happen to know who decided to do that weighting of the months, or why it was decided to do that?

Harris:

Well, Iíd done a much simpler approach, which was just taking the means for Arosa, which starts in 1926, up through 1970. So itís really simple: you just calculate the long-term average for each month, and then you do the same for after 1970. You subtract them and you see a difference, but itís quite hard to get a statistical significance if you do that. So you then see the seasonal pattern. So immediately you have to think, ďWell, how do I actually do it as some sort of linear trend?Ē which is the shape you have to use. And then it falls into place. I was talking to someone I guess from one of the social sciences, because they had the software, which we didnít in chemistry, to do the trend in that and to do statistical analysis. So it would have been a mixture of me and Sherry and this guy over there helping more on the technical side.

Brysse:

Right. I find it really interesting that so often, not just in ozone depletion or chemistry but in science in general, you have to make decisions about what assumptions youíre going to put into your calculations or your models or whatever, and so often it turns out that those things are masking something that you just couldnít have known it was there.

Harris:

Absolutely.

Brysse:

Like with the ozone hole, how the satellites at the NASA program was actually calibrated to ignore anything below 120 Dobson units.

Harris:

Yeah, the software factored it out. Yes, thatís right. But it was because I did the simple analysis first that we knew that that behavior was there, so when we did a more complex analysis, you allow for that in the analysis. So that was the reason because we had done the simple one just calculating the differences for each month first. Then I went down to La Jolla. In those days you couldnít get all the data on the web, so I had to scroll through all the books and get out the ones for Bismarck and Edmonton and wherever else.

Brysse:

Thatís where Iím from is Edmonton.

Harris:

Right, okay. Well, thereís a long-term station at Edmonton from 1957, I think it is. So you have to actually write out the monthly means for those. So I spent a long day in La Jolla doing that, and then you go back and do the same sums as youíve done for Arosa but for much shorter datasets, and you start seeing the same patterns with some differences between the continents. But once youíve done that simple analysis, then you think well, how do you actually put proper uncertainty limits on, which is what you need. Is it a fluke? Then you think, well, instruments measure worse in winter than in summer because the sun is lower in the sky, etc. So you have to have the faith in the measurements and not just use the published data, which was all I was doing in the first analysis. So thatís where the stuff Rumen was doing came in with, came in extremely timely. Sherry must have just met him at a meeting. Then he got involved doing that in the ozone trend report, which Sherry was chairing a chapter for the ozone trends. Therefore, once we were both working on the chapter, it became natural that he was doing that and Iíd do the analysis.

Brysse:

Iíd like to hear more about the actual writing and discussing of the Ozone Trends Panel report.

Harris:

Well, first of all, it was a good group of people on the chapter who individually knew different parts of it. So there was Rumen, who as youíve probably heard is a strong character, which so often upsets other people. Then there was another guy on the ground-based instruments, another key character was a guy called Walt Comer [?] from NOAA who had been responsible for the absolute calibration of their instruments probably since the early Ď60s, but again, he wasnít the best person at explaining what he did ever. So it was only in those meetings where you also had some of the NASA people like Rich Stolarski or Rich McPeters, and from industry there was Mack McFarland. I would think particularly Rich Stolarski and Mack McFarland were just very good at asking the right question. I mean Rich Stolarski would have had some bias because heís from NASA, but they basically knew the question to move the argument on rather than to entrench your position further. Iíve forgotten how many chapter meetings there were, but there were probably two or three of them at the time, and it was fairly obvious after the first one, although Walt probably didnít give the best description of what heíd done with the instrument, but it was actually very hard to see what he had done wrong from what he said to start with. So then he came back with a much more detailed description of how —

Brysse:

Iím sorry. That was Bojkov?

Harris:

No, no. Walter Comer with first the U.S. and the international standard instrument, which certainly from 1970 formed the basis of the calibration for the network. If youíve got a good instrument (and Joe [Farman] will probably argue this later on), you donít need to link into a calibration system, although Iíd argue it gives confidence. But when you have a lot of bad or poor records run by net agencies, then itís a huge problem. So the fact that you could then trust this one instrument meant to a large degree you could trust the corrections that the comparisons that had been done implied. So if Walt Comer, who as I said couldnít normally explain himself that well, if he hadnít done such a good job from early on, it would have been much harder to pick out the errors and trends or to have confidence in the errors and trends, particularly in the northern hemisphere. In the south it was fine, or at least in Antarctica it was fine. But in the northern hemisphere, that type of work — going back to 1963 he started it, way before it was an issue of great public concern, any public concern. So he and Rumen Bojkov to me were always the slightly unsung heroes but because of personality in the whole process.

Brysse:

I forgot to ask you, was your analysis just the ground-based Dobson Units —

Harris:

Yes.

Brysse:

Öor everything?

Harris:

Well, Iím not actually that good at computing, so I couldnít have handled the satellite data. Hardly enough; Iím not that good at it.

Brysse:

I feel the same way about statistics. I was good at it when I took a class in it, but that was at least 12 years ago and Iíve forgotten everything.

Harris:

The maths I can only understand; itís just computer. I donít like programming, which is not a good character for a scientist to have nowadays.

Brysse:

No, exactly.

Harris:

So there are probably two or three, and the first one, Walt Comer put sufficient forward to worry NASA. So Rich McPeters from NASA in particular went back and did some careful tests, and on the same —

Brysse:

Meaning there is a trend or there might be a trend?

Harris:

No. The TOMS wasnít necessarily right. They had come to the first meeting thinking, ďNo, well weíve done a lot. There are a lot of checks in it,Ē which there are. Itís probably right. But then they went back and went, ďWell, if heís looked at thatÖĒ because the technique isnít that different. Youíre looking at the UV absorption and stuff like that.

Brysse:

Right. Did they already know about the degradation of the diffuser plate thing?

Harris:

No. This is when it was coming in. So they came in thinking, ďWell, thereís nothing there. But our technique we were takingÖĒ There were enough worried from the first time that they went back and looked carefully. Then I think probably for the second, certainly for the second major meeting, they came back with the diffuser plate, and Walt Comer came back with the full — And he spent about an hour going through his. If it wasnít important, it would have been incredibly boring. It was one of those talks going through it, and everyone was trying to pick it apart and you couldnít. Then Rich McPeters was saying, ďWell look. It actually looks like this.Ē They may have been slightly in different meetings, but the process was he did enough to worry NASA. NASA checked into it and found a diffuser plate not being stable.

Brysse:

Right. Thatís something else that I think sometimes historians like myself, and certainly the media and the public, donít always really get is how carefully reputable scientists check everything. You donít announce something, you donít say you believe itís true until youíve really thought about, ďAre my instruments looking at what I want them to look at? Are they working properly? Am I analyzing them the right way? Am I talking about them the right way? Am I asking the right questions?Ē Of course scientists sometimes get things wrong, but you are thinking about all of those things.

Harris:

Yes, and I think in an individual paper, different scientists would do the care to different degrees. Thatís painting scientists in a saintly way which Iím not sure is quite there. What the assessment process always gives is the rigor to make sure that whatís published in a paper which has two reviewers who canít ask questions of the author — the papers are judged by many more people, a) the author team, and b) the reviewers of the chapter, which is multiple.

Brysse:

Right. So does the rigor just come from the greater number of people or is there something else going on?

Harris:

I think the point is youíre trying to assess the position of the science in a broader perspective. So a) that means youíre asking slightly different questions of the paper than you would as a reviewer whoís saying, ďWell, what is the meaning?Ē or ďDoes it fit in with everything else?Ē in a way that as a reviewer, youíre more saying, ďIs the logic right?Ē As a reviewer, I would let papers in which I thought might come to the wrong conclusion, but I thought it was a well-justified rationale, and if it was interesting but basically. Whereas a writer of an assessment chapter, youíd say, ďHowever, so-and-so found this which is interesting but does not fit in with common knowledge.Ē As a reviewer, you shouldnít stop something being published. I donít think you should stop something being published if it doesnít fit in, whereas in an assessment chapter, you have to make that judgment as well. So just starting that discussion, and a number of people which you ask back comes in, because you then got more perspectives on that, and I think thatís where that use comes in. Plus, Iíd read a paper and not see a mistake in it, and someone else would say, ďYou know, that doesnít really fit like that,Ē and you immediately then get the more extra knowledge coming. So Iíd say over half is the number of people where the good chunk is youíre just looking at the paper in a different way. But I wouldnít make the scientists too saintly.

Brysse:

Well, thatís the goal, I guess.

Harris:

Yeah, the aim is to do that certainly. I would try and do that, but I wouldnít necessarily succeed, or everyone else succeeds.

Brysse:

Okay. How about the writing of the report? I got the impression from Rowland that you did most of the writing or at least the collating — people were sort of sending things to you.

Harris:

Probably. I did most of the writing of the ground-based trend analysis because that was the work I did for it. Well, I would have done all the writing, and then the normal Ph.D. supervising, he was changing it. Then youíd send it back to him and he would change it back to what it was the first time. That was always his trick. Yes, I would guess the other people were sending their text and I was putting it together. So Rumen Bojkov would have sent me the text, which probably needed quite heavy editing.

Brysse:

For language?

Harris:

Yes. He loved detail, too. So yes, I was trying to make it smoother. And Rich Stolarski or Rich McPeters for the satellite stuff. So I canít remember the whole scope of the chapter, but it was probably done that way because Sherry was the lead author. So it would be done in Irvine, yeah.

Brysse:

Was it awkward at all, you not having your Ph.D. yet at the time and established scientists sending their work to you and you were sort of in a sense correcting it?

Harris:

No, but that may be a character strength or flaw, depending on how you look at it, on my part. I mean if you can hold your own at the meetings, then the respect is there. If you donít hold — If I was saying stupid things at the meeting, I donít think it would have worked like that. But I donít think I did say so many stupid things. Again at a chapter meeting, you were allowed to ask basic questions in a way that in seminars looks odd, sort of really probe whether the basics of someoneís technique is right was entirely what that chapter was about. So I could ask dumb questions in terms of expertise which were good science questions. So I donít remember it being awkward. Rich Stolarski and Rich McPeters were dead easy to work with. So was Mack McFarland. Rumen was Rumen, you know. But I donít think that was any different as someone who wasnít doing a Ph.D.

Brysse:

How was it decided who all was working on this chapter?

Harris:

Well, the system was very different back then. Iím pretty sure Sherry would have been chosen. I donít know, but that would be a question for Bob [Watson] or Sherry. Iím pretty sure back then that they chose the chapter chairs, and then they chose their team to get the job done. So itís very different now to where youíre thinking about national or gender or expertise and age is now an issue now, which it wasnít then.

Brysse:

You want younger people so theyíll be able to work on it longer or the opposite?

Harris:

Oh, and to get a fresh view. Yeah, not to be — I mean you could talk to John [Pyle] tomorrow morning, but Iím sure thatís — And then when Iíve organized and been involved in the discussions recently either informally or formally for this assessment or others, you want a spread of people. I think back then, it was a greater urgency that that paper being published, the expeditions are going on it in the South Pole. You wanted the job done. There are big plusses of doing it that way. Itís more fun as a scientific enterprise, I think, than it is nowadays where itís much more bureaucratic. But you should probably — Because I was the Ph.D., I wasnít involved in that selection, I suppose is what Iím saying. The impression was that Sherry knew that Rumen was doing this work and could get it done for the chapter, etc. I think thereís a guy called Peter Bloomfield on the chapter, too, who is actually a statistician.

Brysse:

His name sounds vaguely familiar.

Harris:

Try checking if heís actually on the chapter. [Look at document] Thatís the list of authors. Peter Bloomfield was on it. Atmans Bacarate [?], I donít think he did very much. And Jim Angel, he had done a lot of the older analyses which hadnít picked it up. I always had Peter Bloomfield, but Peter Bloomfield was a real statistician. I think he actually worked in Wall Street. But he then was a professor in Raleigh, North Carolina.

Brysse:

I have a question about assessments in general, and that assessment in particular. Do you think that assessments generally donít contain new scientific information or claims but sort of just collate things that are out there already in papers? And that even if thatís generally true, do you think this Ozone Trends Panel assessment in particular did have new science?

Harris:

It did. My thesis was not a published paper, so yes. It would never get in now. One of the interesting things about the series of ozone assessments, if you include that in the normal WMO/UNEP series, is theyíve become more IPCC-like over the years in the sense that the review process is stricter. The rules about whether a paper is published or not are stricter than they used to be. There are plusses, but there are clear minuses from that, one of which is itís actually less fun for scientists now, I think, because it is a more rigorous process. So there are scientists I know who I donít think have been involved in IPCC for the last ten years because the fun is in writing the first draft and the first review, not in the subsequent reviews. So I think a) youíre risking the way youíre picking probably from a pool of different scientists as they get more bureaucratic, which may because government scientists, government people working or NASA or NOAA are more likely to be encouraged to do that, to be involved. Youíre picking a different pool of scientists, and I think there is a risk there which hasnít been properly acknowledged. The other one is the newness of the science. Yes, I do think itís gotten too heavy, is my own view — IPCC and this to some extent. I mean theyíre just about to start another one, so weíll see how that goes. You can ask John about that tomorrow. But my hope would be that it can be lightened, but I havenít seen the trend reversed yet, so Iím skeptical whether that actually happens.

Brysse:

Right. You mentioned thereís a risk involved when you get the people from NASA and NOAA. What was that risk? I didnít catch that.

Harris:

Itís not particularly any of the people I know, but I think itís harder for university scientists to commit to something like the current IPCC process because it is a hell of a time commitment for which youíre not paid. You donít get any particular bonus inside your institution, and if youíve got teaching duties as well as a research group, itís just an incredible load. So youíre basically limiting the pool of people you pick from. Beyond that, thereís a potential risk, which I donít think is going to happen, but you are picking from government institutions where you would be allocated time and resources to do that job.

Brysse:

Right. So if theyíre all from that institution, they could not necessarily represent everyoneís views.

Harris:

Yeah, and I donít see it as government trying to influence whatís in the report. They do that through the reviews for sure. I donít think itís them trying to influence it in that way. Itís just youíve got a different pool, and a different type of people do work for people like the MET office in the U.K. than for the universities.

Brysse:

Yes, and that is a problem. On the one hand you want the experts in the field to be the ones working on the assessment, but if theyíre spending all their time doing the assessments, they will no longer be the experts in the field.

Harris:

Absolutely, and I do think IPCC especially has gotten that far, because I was involved in the IPCC report.

Brysse:

Which one?

Harris:

The second one and the aviation report. I forgot what they called it. I was working in the technical support unit from here, but I was doing the chemistry chapters while I was here. Then it was reasonably light but still heavier than these. But itís just gotten much heavier since then because thereís a big step from the second report to the aviation report because youíre trying to pull industry in and get their faith and all that sort of stuff for the aviation and for the other one itís government as well. But if you can transfer it with this one where they had the Les Diablerets meeting, I think I always did some recalculations for them because people ask questions correctly in the meeting, which were answered by the new analyses that were done. And as I say, the work was never actually published other than my thesis, which Iíve never had that many requests for copies. Well, none.

Brysse:

Because itís all there.

Harris:

Exactly, yeah. And the review process would be tougher for this for a paper.

Brysse:

I was just going to ask about the review process. Who reviewed your chapter for this report, and what kinds of things did they ask you to change?

Harris:

I canít remember. I assume that they would have had eight or nine reviewers who went to the Les Diablerets meeting, which I didnít go then, and it was discussed then because it was fairly central to it because it was showing the trend. But I donít know who they were or anything like that.

Brysse:

I was actually a little surprised when I read that Ozone Trends Panel report myself. Iím trying to remember exactly what I thought while reading it. I think it was that while I was reading the introduction, it didnít sound to me like much had been found in the way of results. But then when I read Chapter 4, it clearly said we have found this trend and we think itís caused by CFCs. So I was a little surprised by what looked to me like a disjunction between those.

Harris:

Yeah, I canít remember. What I do remember as I was doing my thesis work was thinking, ďOh good, thereís a winter trend. Iíve got a result. Can it be any bigger? Can I make it any bigger?Ē Then you suddenly think, ďOh, that means thereís more UV,Ē you know. So in a way you didnít mind which result you got, but it was there. I knew it was there. So Iím not sure how strongly we made a connection to chlorine in the chapter because it was sort of technically we were just doing the trend work, and the understanding on the ozone — Iím not sure we still understand what the trends are completely in the northern mid-latitudes, but it certainly wasnít that advanced then. I mean I remember giving a talk on it and it was a fairly hand-waving argument at that time. So Iíd have thought we just did the trend itself. But yes, thatís what it was.

Brysse:

That leads me to a question about the assessments. A lot of people like Bob Watson for example feel very strongly about this, that assessments should be policy relevant but not policy prescriptive. Would you agree with that? Were you all careful when writing this report to explain the science clearly but not make policy recommendations?

Harris:

In this report, I doubt it was an issue. It was just get the science right. Itís more —Yeah, I agree strongly with that — you canít be policy prescriptive with it. I mean you can show what the options are because youíre not the expert in saying what happens if we change this economic measure of this technicals with subsidies in this area. Weíre not the onesí who know that, and there are people — If there werenít better people around, maybe we should be policy prescriptive. But what you have to do is give the clearest message of ďIf you donít do this, this will be the consequence,Ē and that is very much what we should be doing. You shouldnít back off that in the slightest, but that doesnít mean you say in this case remove CFCs with a five-year phase-out versus a ten-year phase-out. We donít know the insides of either the industry or the government side on that. So thatís wrong. That doesnít mean scientists canít personally express their views. I donít, but others do, and I donít think thatís wrong. But as long as you separate the science from the view, as it were, at least internally, then I donít see any problem with that.

Brysse:

It also seems to me that those scientists who have expressed their views clearly and publicly on which policy they support tend to be less often invited to participate in further assessments, because perhaps theyíre seen as clearly partisan towards a particular policy.

Harris:

I donít know. I mean Sherry was asked to do that chapter for this assessment. He had been pretty vocal.

Brysse:

Right. But thatís really the only assessment that he participated in, which surprised me at first. But that was the reason that he gave for why he thought he hadnít been involved in many more assessments.

Harris:

Yeah, I mean heís in a better position to answer that. Or Joe in due course, or Paul Crutzen, for which all three of those thatís true, whereas Mario Molina I think was more involved. Iíd have to check that.

Brysse:

As far as I know, he was. I havenít talked to him yet. He was more involved in assessments. But on the other hand, he was also, Iíve heard, perceived as less political than Rowland.

Harris:

So the question would be were Bob Watson and Dan Albritton and the selectors in order to be able to sell the document better when it came out to the delegates to avoid those people.

Brysse:

Right.

Harris:

Yeah, I donít know. In selectingÖI mean when I was involved in some of the discussions for the IPCC, they wouldnít be the lead author principally, but the other discussions, I donít remember that being particularly an issue. I mean Jim Hansen I think has been involved in IPCC reports, as have others. I remember some explicit cases like Richard Linson where itís felt better as a skeptic to get him involved than not involved in those cases. So whether that was different with the ozone assessments I donít know. Thereís no a priori reason why that need be the case. I do think that. Because if youíve got the strong views — From the assessmentís point of view, if you can actually show thereís a consensus on these broad things, even if people then either have views beyond the scope of the assessment or scientifically still have some queries on it, then itís a stronger assessment to my mind. So I donít see a priori why that need happen. In the states with Sherry it had been fairly vitriolic at times, so I donít know whether that was an issue or not. I wonder if Bob would have thought or run scared of that issue, but he may well have made a decision and he should have told you if youíd asked him.

Brysse:

We did talk about it. I donít remember exactly what he said. I think he said basically that he felt very strongly that Rowland should be involved with the Ozone Trends Panel report and that in some senses it was a bit of a special case, like its new analysis of data that itís a little bit different from some other assessments.

Harris:

He was very even-handed in this. The political viewsÖ

Brysse:

Yeah. Well, he certainly didnít think that Rowland would ever be biased if he was involved with an assessment. But I think he did mention that he was aware that there might be some people involved with policy making who would perhaps look at a document, see a certain personís name on it, and think clearly it will be expressing this personís view that I already know about from their public discussions and what policy they think should be followed.

Harris:

Yeah, in his case I wouldnít have thought — And there are somewhat iconoclastic scientists who — probably Jim Lovelock is probably one — who would probably not work in an assessment process, so those itís hard to know what to do with. I mean Paul Crutzen is a little bit like that. Heís always following his own ideas at any stage, and that mentality is hard to fit into an assessment process. But thatís for a different reason. Thatís his, ďAre they just going to drive the chapter with their current ideas rather than try and answer the questions?Ē So thatís different to the motivation of your question.

Brysse:

Right, exactly. Is that process, trying to get different people to work together and come to a consensus, is that a lot different than, say, writing a scientific paper with two or three coauthors? Or is it the same process, just bigger, because there are more people? Or is there someÖ?

Harris:

Oh, itís bigger because in a chapter, you donít — If youíre writing a paper, thereís a fair chance that youíve got the expertise to cover all sections. Itís not necessarily true now if youíve got a mixture of measurements and models or something like that. But in a chapter, certainly no. Thereís one bit that youíre the expert on, and you should know about the other bits, but you probably could not write those, especially with the way the literature has expanded. Iíd probably reference 12 trend analyses papers in these previous ones, certainly there are many more, but there are probably four groups doing it. Now thereís a huge list to start with, so the literature has expanded. So you tend to know one bit. So the interest, the plus of being involved in assessment is just the sheer interest of getting up to date and pre-publication, and this is pre-publication during the preparation of the assessments, is really getting up to date over a wide range of science, so not just your chapter but the other chapters, too. I mean thatís the fun. So no, itís a different process because of all that.

Brysse:

Right, and thereís perhaps less arguing because everyoneís aware that I am an expert in this area but not necessarily in that area.

Harris:

Oh, no, no. I donít mean thereís less argument. No, no. No, no, no. Scientific pride means youíre trying to prove people wrong as well as right. No, no. Thatís not right. Iíve seen far worse arguments in the assessment process than in writing a paper.

Brysse:

Really? [Yes.] Very interesting.

Harris:

No, if some of the skeptics came to the scientific meetings preparing, people will argue for half an hour on something really minor, and thatís just all straight pride. And wanting to get it right. You donít object to that. You want to get the details right. But no, no, there are huge arguments in an assessment.

Brysse:

So what do you feel the impacts of these assessments have been? Anything youíve been involved with in general, Ozone Trends Panel in particular, do you think that they were important in influencing policy?

Harris:

Yes, because they are the root to the political process.

Brysse:

So what exactly do they do to have an effect on policy? What role do they play?

Harris:

Well, normally the last chapter relates back to your political question of where you show the scenarios if you have a 90% reduction or a 95% or a 50%, this will be the effect on the chlorine levels in the atmosphere, and by implication the UV levels at the ground. Thatís always slightly dodgy just because the clouds, youíve got all the other factors coming in. But the question isnít posing about clouds, but saying, ďCan we minimize the effect on the UV from the CFCs and any other ozone-depleting gas?Ē So when you show that, basically the earlier chapters are showing the strength of evidence, or in the case of the ozone trend chapter, they show you what the trends have been and the best understanding of why theyíve been, given that itís not only chorine. Then the other ones show, ďWell, this is where weíre really short. Itís the chlorine and this is why weíre not so sure itís chlorine, or it may be the climate change creeping in the back door.Ē Whereas the last one theyíd say, ďNo, if you get a 95% reduction, it will have this effect.Ē Iím sure, from when Iíve seen policy talks given, they may find the early bits of interest depending on their own characters or depending on their backgrounds, but itís the last chapter that they really look at. If the first part is convincing, then the last part is what they look at, and then theyíll tweak that given their backgrounds and whatís politically feasible, etc.

Brysse:

So what the policy makers are doing with the assessments is using them as the source of their policy options, maybe? [Yes] Good. That sounds good. Have you been involved at all with heterogeneous chemistry?

Harris:

A little bit because there was a bit going on — not directly, but when I was there because I noticed that in your email or your talk thing was — I think it was water plus chlorine nitrate. Sherry had a Japanese post-doc trying to measure. He couldnít get it right, so they both thought they had screwed up. They were trying to do the gas phase measurement and itís very slow. So finally when the thinking was developing about what was causing the ozone holes, thatís actually a positive result, not a negative result, because itís a surface.

Brysse:

So why would you say that heterogeneous chemistry hadnít been considered before the ozone hole? Rowland and Molina mentioned it in their 1974 paper. They sort of said in the last paragraph, ďOf course we havenít looked at heterogeneous chemistry and it might turn out to be important,Ē but nobody looked at it really until the Antarctic ozone.

Harris:

Well, in their original paper it wasnít that relevant, or from current knowledge it wasnít that relevant because it wasnít going to remove the CFCs from the atmosphere. From the point of their paper, it was the CFCs arenít removed. They wouldnít have thought about whether chlorine was activated by heterogeneous chemistry in that first paper.

Brysse:

Why wouldnít you think about that?

Harris:

Itís too big a step.

Brysse:

Okay. Because?

Harris:

They had made two pretty big steps already by the fact theyíre lasting 100 years, and they will photolyze. Why it wasnít then picked up soon after that, well, you should ask Tony because he is a lab chemist when he comes in. Itís probably because itís still hard to make measurements in heterogeneous chemistry because you donít know what surface youíre preparing in the lab, and so Tony at that stage would have been involved in the sulfuric acid, acid rain stuff where in the droplets it was important. In Occamís razor, you try and solve it in the simplest way. I think that was operating to some extent — that, coupled with the complexity just put off doing much about it. My guess is also the fact that polar stratospheric clouds existed was not — There was division of communities, so the atmospheric chemists, unless they were interested meteorologically, would not have known particularly that there were polar stratospheric clouds. People like Joe who had been to Antarctica would know, but I donít know of any measurements until 1979 by satellite before the first satellite paper came through. Prior to that, they were called noctilucent clouds, or whatever their qualitative name was up till then. So theyíve been seen. They would have been seen at the Trump [???] zone, places like that. But there were no real measurements of them to my knowledge, and so sort of how firm is it that these things are there? How often are they there? Could they play a role? Theyíre there in the dark. Howís that going to help? So it was probably a whole scope of things like that, whereas there is enough to do in the gas phase without getting caught up in the heterogeneous. But Iím sure these two had strong possibly different views.

Brysse:

I will ask the others, but your perception then is this changed because then the Antarctic ozone hole was discovered; it was unusual, and therefore might need unusual chemistry?

Harris:

Absolutely. You couldnít explain that by gas phase. It was very obvious.

Brysse:

You worked on some other assessments as well, those WMO/UNEP ones. Is it those?

Harris:

Yes. I donít think this was formally in that series. I donít think it was formally asked for by the parties. It was just clearly a good idea. So yeah, no Iíve been involved in a lot of those.

Brysse:

Was working on them basically similar to working on this?

Harris:

Yeah. But as I say, gradually over time, the review process and the publication policy has become stricter.

Brysse:

Right, which makes it less fun.

Harris:

I think so, yeah, as a scientist.

Brysse:

Mm-hmm [yes]. And has it been the case that the fact of ozone depletion and the fact of the involvement of CFCs have been established over time, which is accepted and taken for granted now, is the assessment process getting sort of pro forma? Are we getting to a point where weíre not going to need assessments of ozone depletion anymore? Certainly we need to continue the policy to manage things like CFCs or phase out things like CFCs, but do we have to keep analyzing it?

Harris:

The legal answer depends on how itís written, so I canít answer that. From a scientific view, in terms of the ozone depleting gases, what is needed is a) continued monitoring that they come down. Whether that needs a quadrennial assessment is open to question, but that probably needs to be done in a way which is formally reported to the parties. Otherwise attention, as is happening with funding agencies, drops off. The second issue is there is a need partly for scientific credibility related to the IPCC process of actually checking whether what we were saying was right and where it was wrong, did it matter, and why wasnít it picked up. This will hopefully become out of date quite soon if the Kyoto process or the FCCC process gets serious, then this may be less of an issue. At the moment, there is still a scientific credibility thing of we do assessments and weíre broadly right. I think itís important to maintain that. But the third thing is, and then whether it legally falls under the Montreal Protocol is open to question, but I think itís best done there, partly because the scientific expertise is assembled best there, is well, whatís the effect of climate change going to be on the stratosphere, on ozone, and on UV? It would be quite possible to do that within the IPCC process. I think that would be a mistake personally, because as I said, I think thatís gotten too clunky. So those are the three reasons why I think international assessments — Iíll go back to that level of phrasing — are important. I am fairly open whether we need to make them four years. I do think scientists have come to see them as a prop in some ways, but we always do them, so we should do them the same. There is a strong argument for making them shorter and itís the scientists who donít let that happen.

Brysse:

Why?

Harris:

Well, once you start writing about something youíre interested in, you do, and Iím sure you do that when you write, talking to the part three students here who have just done a two-term project, they are all way over page limit. Itís human nature. Itís nothing else, apparently. But equally, that isnít necessarily helpful for the parties, and Iím not sure itís a good use of scientistsí time in that you actually want them to be spending more time on research, not less.

Brysse:

Right. I think you said you were going to come back to international assessments.

Harris:

I just think an international assessment is valuable. I think the system under WMO/UNEP and the Montreal Protocol is working well. So on the ďif it ainít broke, why fix itĒ principle, you might as well try and leave it in that because the people receiving the documents sort of know what theyíre going to get. We know roughly the type of thing we want to give them, at least an executive summary-type.

Brysse:

Right. I was going to ask about that. Have you seen an evolution in the format of the assessments that youíve been involved with? For example, Bob Watson said the thing that he regrets the most about the Blue Books assessment was that it didnít have an executive summary, and he told me exactly what, in his opinion, the difference between an executive summary and an introduction is. So for example, thatís one thing that he has changed over time. Has anything else like that changed?

Harris:

Well, in the IPCC process and I think this was a good thing because actually we were trying to write an executive summary for the 1995 one that became 30 pages, and was not being accepted by the parties. So that then became a technical summary, which is I think they do still have and is 30-40 pages. I think that is very valuable, not necessarily for the people who actually attend the meeting but for anyone who wants an overview of climate change later state in 30-40 pages whoís got technical interest, I think thatís a terribly valuable resource nowadays. Itís partly because climate change is so complex.

Brysse:

Right. Whatís the difference between that and the executive summary? Just length?

Harris:

Youíre trying to say things much simpler, and yes, length and simplicity, different audience. Youíre aiming it more at — Yeah, itís like chief executives should receive one page. So youíre not aiming the technical summary at them. The other thing I like are these public questions, 20-question type thing.

Brysse:

Right. Iím aware of them, but certainly I donít think Iíve read all of them. But I understand they came about in the first place because of silly answers that industry was trying to put out.

Harris:

That was one of the motivations, but Iíll put it slightly more positively in that weíve always sent them because we normally try and get 20 or so on each assessment to schools and stuff like that. Iíd put a more positive spin on it than that. I think there was a reason — and actually the research scientists coming in donít know all the basic arguments. So I think just having that resource is — And probably from the start it was known that was part of the rationale. A lot of it was defensive, as it were, but I think there were more positive reasons to. I think the IPCC one was done because Michael Oppenheimer and I had a beer. I think it came out of a beer. Because we knew it was happening for the ozone assessment, and over a beer we thought, ďWell, why not do it?Ē He would probably say it was just him.

Brysse:

[Laughter] Iíll have to ask him. One more question.

Harris:

But otherwise, theyíve become much more structured and so you know that youíre going to write an executive summary, so as you write the chapter summaries, youíre thinking what could transfer up. So, all that process is better known by the scientists writing it.

Brysse:

Right. Okay, great. A lot of the books that Iíve read describe the creation of what they call the ozone regime as this big success. Scientists figured out there was a problem, policy was implemented to take care of it, and now weíre fixing the problem. But then I read another book by Sharon Roan, I think hers is called Ozone Crisis, and she describes it as something that did eventually succeed, but it happened 15 years later than it should have. Talking to Rowland, for example, thatís very much the way he sees it. He saw it as a clear problem in 1974, and the Montreal Protocol isnít until 1987. In his opinion, it just didnít need to have taken that long. So do you look at it as a success story or not a success story or something in the middle?

Harris:

Something in the middle. I do think itís a success story because it did work, and they still made changes at the last time round to reduce how long you can produce the HCFCs and stuff, which has had a big impact on the climate change. So I do think that just that level of trust that was built up is a success. Could it have been done earlier? Yes, and Joe will give you strong views on that. Yes, it could clearly have been done earlier with the evidence available. Pragmatically, do I think it could have been done earlier or not? Probably not. Thereís an inertia in the system. But from the available evidence, if people actually believe that and have had an assessment on time, as Bob said, possibly was there something in the Blue Book to do it, yes, you could argue they should have taken the message on board and acted earlier.

Brysse:

Right. Well, it may not have had an executive summary, but it had an introduction, which I learned isnít exactly the same thing. But it did contain in only a few pages the results from each chapter. So why isnít the same thing happening with climate change? I mean the IPCC exists. Theyíve presumably learned the lessons from these assessments. They include executive summaries and yet, weíre not really —

Harris:

I think thatís a really interesting question, and my reading of it at the moment is industry has learned more than the scientists or the science process has. The scientists — which includes Bob Watson, so probably all the way down — probably gone along thinking, ďIt worked well for Montreal. We should be able to get it to work well for Kyoto.Ē The problem is the industries have seen that, so thereís been a lot more obfuscation or just slowing things down. So they got it right. A lot of the analyses Iíve heard or read have shown much stronger links with tobacco industry response in the Ď50s rather than DuPont or other chemical industry responses in the Ď70s, Ď80s, or Ď90s. DuPont early on wrote that letter saying, ďIf there is a problem, weíll stop,Ē and no company has done that on this issue. Individual ones have taken action. BP you can argue either way, but DuPont —

Brysse:

Right, but no one has said, ďWeíll stop making cars that run on gas.Ē

Harris:

No. The other thing clearly is that itís just a much more complicated problem because there are so many sources. But I do think industry and the skeptical lobby have learned well from the Montreal process much better than the scientists or the scientific assessment process has.

Brysse:

Right. Thatís very interesting. I hadnít thought of it that way, but it makes a lot of sense.

Harris:

Yeah. My view.

Brysse:

This comparison to the tobacco industry in the 1950s — did you say you had read that somewhere?

Harris:

Yeah, Iíve either read it and/or heard it on the radio. Itís basically keep a lot of data in-house; deny, deny, deny until you really have to; and preferably put out false information fronted by other groups out in the public arena, which was certainly done by the tobacco group and now Exxon has certainly done that in the U.S.

Brysse:

Really?

Harris:

Yeah, the coal industry has.

Brysse:

Iíll have to look into this. Good. Thank you. That might be all the questions that I have. Is there anything relevant about your work that we havenít talked about?

Harris:

I havenít a clue. Iíll think of it. But if youíre around tomorrow —

Brysse:

Yeah, I will be around tomorrow.

Harris:

Yeah. And weíve got the seminar today, so it will come up, but I canít think of anything.