A bonus Turnstone

An interview with semi-retired climate scientist David Wratt (15 minute read)

As a followup to the article a couple of weeks ago about the IPCC, in this interview I talk with David Wratt, who has many years of involvement with the IPCC as both an author and reviewer. As well as insights into the IPCC process, he shares some of his experience with a historic court case where New Zealand’s National Institute of Water and Atmospheric Research was taken to court by a group of climate change sceptics.

Also, before I forget - Substack has introduced a new feature called “Notes”. It’s like social media, yet not like social media. There’s no advertising and what you see is driven by who you subscribe to on Substack, not by algorithms tuned to amplify outrage. I’ve been using Notes to share some of my favourite Substack newsletters, and I’d love for you to join me and tell me about what you are reading.

I hope you enjoy this interview. I’ve got a couple more interviews in the pipeline, which I will be sharing with my paying subscribers. One interview is with a scientist who works on pine trees and one with a scientist who works on toxic algae. There will also be articles on these topics which will include parts of the interviews, and those will be available free. I want to keep as much of this newsletter free as possible, but I also want to show my gratitude to those who have supported me (and if you’ve supported me through buy me a coffee and would like to read the interviews when they come out, let me know).

Me: How did you come to be working in climate science?

David Wratt: I grew up in Motueka in the north of the South Island and was quite keen on physics at school, so I decided to go to university rather than work on the family farm. I did physics at university, and finished up with a PhD from Canterbury University but a long, long way away from climate change. I was studying what was going on about 80 or 90 kilometres up in the atmosphere using a special type of radar. I went to the US to do some more work in a similar area but decided the number of people that wanted to know how many electrons there were at 90 kilometres was fairly few around the world. I’d always been keen to do something that was reasonably practical and applied.

So, when I came back to New Zealand in 1976 I started working for the Met Service. That was the time of “Think Big” and the Met Service was involved in doing studies of locations where it was possible that new industries would be built. I got involved in figuring out if there would be any air quality problems from, for example, building a power station or building an aluminium smelter in specific locations. That involved quite a lot of fieldwork, doing measurements, building up detailed information about the local climate, flying balloons to see where they went to under different weather conditions, that sort of stuff.

While I was at the Met Service climate change was becoming more of an issue. I attended a conference on “Climate Change – The New Zealand Response” organised by the Ministry for the Environment in 1988. My early activities included writing an article on likely effects of climate change on air quality in New Zealand (in 1990), and leading the writing of a document called Climate Change, the Consensus and the Debate which was published by the Ministry for the Environment in 1991. This outlined the science behind why we expected the climate to change.

Me: So that’s interesting. To an outsider like me, the conversation about consensus seems quite recent but obviously it goes back a long way. At that time, how confident were we about the science behind climate change?

David Wratt: Even then we were pretty confident that humans were changing the climate, the evidence was pretty strong. The questions then were “by how much, by when, and what we could do about it”. These are areas that have seen huge steps forward since those days.

In 1992 NIWA (the National Institute for Water and Atmospheric Research) was set up, and for a while I got involved in air quality stuff again. But somewhere amongst all of that I became the chair of the Royal Society New Zealand Climate Committee. So I was getting more and more involved in climate change issues.

The Intergovernmental Panel on Climate Change (IPCC) got underway in 1988 and I soon got involved in putting together New Zealand submissions on the draft reports. Then a colleague of mine who had been chosen to be a coordinating lead author for the Australia New Zealand chapter in the IPCC Third Assessment impacts report (eventually published in 2001) moved away from New Zealand.

I was selected to replace my colleague as coordinating lead author for this chapter, along with Dr Barrie Pittock, a very well-known climate scientist from Australia. I worked with various scientists in Australia and New Zealand, putting that Australasia chapter together. I also helped to set up something called the New Zealand Climate Change Centre which was a science collaboration between Crown Research institutes and most of the universities.

In the meantime I continued to be involved with the IPCC and in 2002 I became a vice chair of Working Group One (which deals with the physical science basis of climate change) for the Fourth Assessment Report. Again, this was because somebody else moved away from New Zealand. Dr Martin Manning, who was a very well-known climate scientist in NIWA went to the US to lead the Technical Support Unit for IPCC Working Group One. I replaced him on the IPCC Working Group One Bureau which is a bit like the board if you like. It’s a small group which helps plan the overall structure for the assessment reports and is involved in selecting lead authors and overseeing the production. I was re-elected to the Bureau for the fifth assessment report.

Me: I’m quite interested to hear about writing an IPCC report. How does that work? There’s all these different people to coordinate…

David Wratt: Well it’s quite a robust process. So I mentioned about the IPCC Bureau. There are the three working groups: Working Group One which deals with the physical science basis of climate change; Working Group Two which deals with climate change impacts, adaptation and vulnerability; and Working Group Three, which deals with mitigation of climate change (reduction of greenhouse gas emissions). Each of these working groups has a Bureau of about nine or ten people. Those groups together with the IPCC Chair, IPCC Vice-Chairs, and the Co-Chairs of the Task Force on National Greenhouse Gas Inventories become the IPCC Bureau.

When it was time to do an assessment, first of all there would be the Intergovernmental Panel itself, the big international meeting of government representatives. It would decide “we want to do another assessment, and it should be done roughly over such and such a timescale”. Also around about that time there would be an election for the IPCC Chair and members of the IPCC Bureau, including the three Working Group Bureaus. So that was when people like me got voted in.

Once the bureaus were set up there were scoping meetings for each Working Group report. A range of people would be invited from all over the world: well-known and respected scientists covering a range of expertise, scientists who had been involved in the last assessment and some people from the government side. Generally there were a couple of scoping meetings which came up with a very broad outline of what the chapters should be and what issues they should address.

So this whole scoping process took a year or two and the outline would have to be accepted by the whole Intergovernmental Panel. Then governments and IPCC observer organizations nominate people to be lead authors. From these nominations, each Bureau suggested teams of scientists who are experts for each of the chapter areas. We’d come up with maybe ten people for each chapter as well as review editors, who were respected scientists who kept an overall eye to make sure that all the review comments that came in during the chapter drafting cycles were dealt with properly. We took those names back to a full meeting of the Bureau where there’d be some discussion and usually some modifications. The goal was to choose experts who reflected a range of scientific, technical and socio-economic views, regions and backgrounds relevant to each chapter. Chapter teams include authors from both developed and developing countries, and aim for a gender balance.

Then each group of chapter authors produces what’s called a zero order draft, a very, very rough draft without all of the detail. That gets sent out to a few experts to have a look at and come back with comments. Then the chapter lead authors come up with what’s called a first order draft of the chapter, drawing also on a wider group of “Contributing Authors” for input on particular matters. The lead authors work together using email, and every now and then there’s a lead authors’ meeting where they all meet together in one place, well, that was until Covid came along and it got rather challenging holding these “face-to-face” meetings by Zoom. The arrangements and activities for a Working Group are supported by a Technical Support Unit.

So the first order draft gets sent out to experts all around the world. Some of those have been nominated by governments, some have been nominated by Science Academies (such as the Royal Society Te Aparangi) and also people could self-nominate as experts. I don’t think anybody ever got turned down for doing expert review. The first order draft is put together as a document with page numbers and line numbers and people comment on a particular line or a particular chapter and then all of those comments are collated by the Technical Support Unit and sent to the lead author team for the chapter. They might get thousands of comments.

The author team have to look through all of these comments and they have to document (in a big spreadsheet) how they dealt with each comment. They might reject a comment if there was no supporting scientific evidence for it. Or accept a comment in part or in full, leading to appropriate modifications of the next draft of the chapter. So you can imagine going through that involves a lot of work! I also mentioned the people called review editors. Their job is to oversee the review process. They look at the drafts; they also sit in on some of the lead authors’ meetings and make sure each of the review comments is dealt with fairly and properly. If there’s some comment that the author team is having trouble with, then the review editors can provide some advice. Over the years I have been a review editor for several IPCC report chapters, including the Australasia chapter for the most recent report.

At the end of all of that the chapter authors come up with a second order draft and that goes out to government and expert review. It goes out to all of those experts that commented on the first draft, plus governments around the world including New Zealand. There’s another whole round with another God knows how many comments that come back in. The authors have to go through this process all over again and come up with a final draft. Doing all of this takes two or three years.

While that’s been going on, the individual bureaus have also brought together a set of chapter authors to draft a technical summary and a summary for policymakers. Again that goes out for government review and a lot of comments come back in. Eventually there is a Working Group plenary meeting chaired by the Working Group Co-Chairs. This is attended by all of the governments and at least one of the Co-chairs from each chapter. These Plenaries approve the Summary for Policymakers, and accept the underlying Working Group chapters. The Summary for Policymakers’ approval includes detailed line by line (and sometimes word by word) discussion and revision, often with contact groups advised by authors set up on particularly challenging issues. This can be pretty taxing and demanding on the participants, but I see it as a strength of the IPCC process.

And it’s done with translators. The translators basically are only supposed to work a certain number of hours a day but as the week progresses you know, at 7pm it’s clear that we’re way behind. The translators agree to stay on until midnight, they get paid extra for that, we keep arguing, all the governments keep arguing. A day before the thing is supposed to be finished you’ve only got halfway through, things get more and more stressed, you work right through the night, sometimes you work on for an extra day or two. It gets pretty fraught at times as you can imagine. The thing is the governments can’t get anything in the Summary for Policy Makers that is not based on something in the chapter and agreed to by the author representatives.

It is possible for a summary to be accepted but with a note that certain countries won’t accept certain things. But usually those countries don’t want to be identified in the final report and they accept the summary at the last minute, by which stage everybody is pretty frazzled. Eventually there is an approved Summary for Policy Makers and also the full report gets accepted. I’ve gone into a lot of detail but I think you can see that it’s a pretty detailed and involved process.

The report process made me think of this image (image credit: Melanie Newfield)

 Me: So that’s the international part of your job. But at the same time you’re still working as a climate scientist in New Zealand.

David Wratt: Yes, I’d also been continuing to lead climate change work at NIWA where I became the Chief Scientist Climate. Also for part of this time there was quite a lot of activity from a group of climate change sceptics who set up an organization called the New Zealand Climate Science Coalition. They made suggestions to the Act Party of lots of parliamentary questions they could ask. This led to around 80 questions in parliament which went to what was the Ministry of Research Science & Technology in those days, from their Minister, then the Ministry passed them on to us and we had to draft answers and send them back.

A lot of this was over the New Zealand “seven station” temperature-time series. That is the record of what was happening to New Zealand temperatures, using measurements from seven places spread across the country which go way back to the early 20^th century. What had happened was that early on the weather stations where temperature was recorded were often located somewhere down near the coast where it was fairly open. Then cities and towns would encroach on them and they’d get moved. And overall, they tended to get moved to places that were a bit higher. So in Wellington, instead of temperatures being measured down in Thorndon, they got measured up at Kelburn where the Met Service was. And when you move higher up, the annual average temperature goes down with height. Dr Jim Salinger and others had developed good processes for figuring out how to correct for these moves. But some of the people in the New Zealand Climate Science Coalition just strung the measurements together, first without making any adjustments at all for site changes, and then arguing that any adjustments should be much smaller than those calculated by NIWA. They claimed the data showed New Zealand’s temperature hadn’t changed by more than 0.1 or 0.2 of a degree and implied NIWA contained a bunch of greeny scientists trying to pull the wool over everybody’s eyes.

Eventually some members of the Climate Science Coalition formed the “New Zealand Climate Science Education Trust” which sought a Judicial Review of NIWA’s work. They challenged the approach taken by NIWA in analysing the historic temperature trends and the conclusions drawn about a New Zealand warming trend. This was heard in the High Court in Auckland, which did not accept the challenges from the Trust, dismissed the application for judicial review, and awarded damages to NIWA. The Trust then went to the Court of Appeal, seeking to challenge the High Court decision. This appeal was abandoned during the hearing, and the Appeal Court upheld the award of costs made in the High Court. There was no payment of costs to NIWA, and the Trust was liquidated.

Dealing with these challenges required considerable effort and time from NIWA staff. This included going back through the climate data, independently checking all of the site change adjustments that Dr Salinger had calculated, and producing a report. This came up with pretty much the same answer, that New Zealand had warmed by heading on for a degree over the last 100 years.

Me: what do you think has been the most frustrating element of being a climate scientist through the years?

David Wratt: I think for me personally, all of the time and the staff resources we had to put into dealing with the parliamentary questions and judicial review. Parliamentary questions and the judicial review process are important parts of our democracy. But in my opinion, when the same arguments keep getting recycled in the face of robust scientific evidence, that can waste a lot of scientists’ time which could have been used undertaking significant new research. Nevertheless, helping the lawyers with the evidence for the judicial review was really important. Because New Zealand was a bit of a test case. If we lost that judicial review case, there would have been similar cases in other parts of the world. They would have really taken off.

Sometimes I got a bit frustrated about the rate of progress in addressing climate change. Who wouldn’t! But I also recognise just how difficult the whole thing is. There has been movement. There have been improvements and while it would be great if we could halt warming to 1.5 degrees, it’s still better if we can halt warming to 2 degrees than if it gets up to 2.5 or 3 degrees. I haven’t felt that if we’re not going to get to 1.5 degrees, it’s the end of the world and my efforts as a scientist have all been wasted.

The work of New Zealand’s Climate Change Commission, developing processes that have buy-in from most parties in parliament is really important. Because the other big frustration, particularly when you look at some countries overseas, is where you have a government which tries to do things about climate change and then there’s a switch in government and it goes back and it’s a real seesaw in progress. Yes, that’s pretty frustrating.

Me: And on the other side, I’m assuming that you have your optimistic moments. What gives you the most hope or makes you feel optimistic about climate change?

David Wratt: Probably the fact that school age students and people in their 20s, a lot of them feel really strongly and are really pushing for action on climate change. The fact that a lot of people are taking climate change really seriously and pushing governments to do something about it. Whether it’s Greta Thunberg or whether it’s people in New Zealand.

Attitudes have changed. Things have changed in New Zealand and internationally and while they haven’t changed as fast as one would have hoped, they have changed.