20140408_JS

Source: BBC Radio 4

URL: http://www.bbc.co.uk/iplayer/episode/b03zr00k/The_Life_Scientific_Julia_Slingo/

Date: 08/04/2014

Event: The Life Scientific: Julia Slingo

Credit: BBC Radio 4

People:

• Jim al-Khalili: Theoretical physicist, author and science communicator
• Professor Lesley Gray: Professor of Atmospheric Physics, Oxford University
• Sir Brian Hoskins: Head of the Grantham Institute for Climate Change
• Professor John Mitchell: Chief Scientist, UK Met Office, 2002 - 2006
• Professor Julia Slingo: Chief Scientist, UK Met Office

Jim al-Khalili: My guest today is Dame Julia Slingo, the Chief Scientist at the British Met Office, where, in fact, she started her career as a meteorologist in the mid-1970s. Julia became the UK's first female professor of meteorology when she was at the University of Reading, during the 1990s and most of the 2000s. There she directed two major atmospheric and climate research institutes. She's one of the country's foremost experts on climate modelling - in other words, simulating climate systems in supercomputers - and did many years of research on tropical climates, including the Indian and Chinese monsoons. Her job, as the Met Office's Chief Scientist, has brought her into the public spotlight and firing line, dealing with complaints about Met Office forecasts about barbecue summers which turned out to be cold, damp squibs, and weathering criticisms and personal attacks from climate-change sceptics. Her most recent clash was over remarks she made about the likelihood of the exceptional rains and storms of last winter being linked to man-made climate change. Julia, welcome to The Life Scientific.

Julia Slingo: Thank you very much. It's nice to be here and to talk to you.

Jim al-Khalili: Well, lots and lots to talk about. Can you, first, sum up what you do, as the Chief Scientist at the Met Office?

Julia Slingo: It's a big job. First of all, I have 500 scientists who work for me, and it's my job to direct them, in the science they do, to make sure that the Met Office - in both weather and climate - is fit for purpose, in five years' time, that we've done the right research, we've developed better forecasts, we've developed better predictions. It's a huge science programme, with a very big budget, and it's world-class. It's my job to make sure it stays like that.

Jim al-Khalili: Can you give a quick definition of what the difference is, between weather and climate?

Julia Slingo: Well, weather is what you experience day to day. It's what we forecast, day to day, in what we call a very - not deterministic but certainly we have a pretty clear idea for the next few days ahead, how the weather's going to shape up, at any place and at any time. And when you talk about climate, you're really talking about the amalgamation of weather, the statistics of weather - so it's the average of the weather that we experience. And so, when we make climate predictions, of course we can't say, on any particular day or any particular place, what the weather is going to be like, but we can say what the probability is of the sort of weather that we're going to experience - say, in a month's time, next year... Of course, for climate change it's all about: will our weather be the same in 50 years' time as the sort of weather we're used to living with, today?

Jim al-Khalili: Can you tell us, Julia Slingo, when it was you think your fascination in meteorology first began?

Julia Slingo: I think really it must have begun when I was at school and I spent a lot of time sitting at my desk in my bedroom, looking out of the window - supposed to be thinking about 'A'-level physics but looking at the sky and wondering about the clouds, but almost particularly wondering why did the winds always blow from the west? Because it's not obvious why the winds should always blow from the west, in our latitudes. And when I went on to read physics at university, I realised that what I liked best was the, sort of, being able to see physics at work, in a sense, and things I could see in my everyday life. So I wasn't terrible drawn by particle physics and that sort of more theoretical physics. And I thought: well, I need to do something that's practical physics, that I can see in action, and immediately the thought came: well, I know what I want to do. I want to study the weather.

Jim al-Khalili: And how, then, did you begin your career as a research meteorologist?

Julia Slingo: Well I was due to go, actually, to do a Masters at Imperial College, to learn meteorology, and at the same time I had applied to the Met Office, for a job as a scientist, and was successful. And when I went back to Imperial and said "You know what, I've got this job at the Met Office", and they said "Oh, you should take that, they're like gold dust." And so I joined a cohort of 20 or so that came in that year, and then I was fortunate enough to be moved, after my 6 months being trained, into a research post in climate, which was I guess the beginning of my career, really.

Jim al-Khalili: Was it an exciting time, for developments in climate research and weather forecasting?

Julia Slingo: Oh yes, I mean, when I entered the Met Office in the early '70s, we'd barely seen a satellite image. We didn't know what clouds looked like from space, for example. We were just getting our first computers. We were absolutely at the vanguard of developing the first climate models, alongside - the Americans had led the way, in the '60s, but we did some groundbreaking modelling of the Atlantic-African climate, as part of a big field experiment in '74, and looking back, the science I was doing then was absolutely amazing, what we were able to do and the insights we were getting, bearing in mind that we knew virtually nothing,really, about how the climate system works, how energies move around the system - we forget that.

Jim al-Khalili: This was also a time and the place where you met your husband Tony, who would then become a distinguished climate scientist himself.

Julia Slingo: That's right, that's right.

Jim al-Khalili: And, and I guess you both worked together - you carried out research jointly.

Julia Slingo: Well, not until -

Jim al-Khalili: Until later.

Julia Slingo: - later on. He was flying around in aeroplanes and doing some amazing work on the interaction of the radiation field with clouds and things like that, so he was very much at the detailed end of things and I was very much working at the global end of things. But it was all about: how does radiation - solar and terrestrial - infra-red radiation move around the system. Absolutely fascinating - there we were, working together and obviously talking about it over dinner, every night. [They laugh.]

Jim al-Khalili: Well, someone you also met in your first years at the Met Office is John Mitchell, who also preceded you as Chief Scientist there.

Julia Slingo: That's right.

Jim al-Khalili: Here are his recollections of what was important to you, as a young scientist.

John Mitchell: One day, Julia, her late husband Tony and I were coming back from the Lake District, where we'd been walking, and we called in at Julia's house, her parents' house in Coventry, on the way home. Her father was actually headmaster of King Henry VIII School in Coventry, and I remember Julia showing her father a reprint of her first published paper. And I think that was significant in what was, perhaps, important to both of them - academic excellence and just seeing the family background was a very strong sense of public duty, which I think Julia still carries on in her present post.

Jim al-Khalili: Which would you say has been the greater motivation for you, the belief in the value of your research to wider society or the intellectual quest, you know, to better understand the nature of the Earth's climate and weather?

Julia Slingo: I think it's been a bit of both, really. I always go back to a wonderful quote from Francis Bacon, who talks about why we do science, and at the end of it, he does say "Knowledge is the rich storehouse for the glory of the Creator". And I think that's what of course drives most scientists, is this gathering of knowledge about this creation we have. But then he says "and the relief of man's estate", and it's the relief of man's estate that I think more and more has become important to me and is why, in the end, I applied to become the Met Office's Chief Scientist, after many years in academia. Because I needed to see my science working for society, for the relief of man's estate. To save lives and livelihoods, to make life better for people who are affected badly by hazardous weather, climate extremes.

Jim al-Khalili: How long have you held the opinion that our emissions of greenhouse gases like carbon dioxide are changing the planet's climate system?

Julia Slingo: Well, right, really, from the beginning of my career. I did some work in the '70s, in fact, looking at what would a doubled carbon dioxide world be like, in terms of temperature, and how would that temperature change depend on things like what the water vapour content - how much humidity there was in the atmosphere, what the clouds did. And I did one of the first studies on that, using a model that I had been writing and working on. And of course the answers came back, effectively talking about climate sensitivity, very close to what we think it should be, today. Which says that the fundamental physics is pretty robust. I didn't at the time, of course, really understand the importance of that particular question. The paper was published in a book called Carbon Dioxide, Climate and Society, but I don't think I had really thought that this was going to be maybe the biggest problem for humanity in the 21st century, as it's turning out to be.

Jim al-Khalili: I think one of the things a lot of people are puzzled by is that you can't. say, predict reliably whether this coming summer is going to be a scorcher, and yet you can talk about the way the climate's going to change 30, 40 years from now. How is that possible?

Julia Slingo: Well, I think there we're fundamentally talking about different things. When we talk about this coming summer, it's a prediction - it's about saying "Knowing today what state the climate's in, can I predict what summer might be like, in the next few months?", whereas when I'm making a projection, I don't need to know what the climate is like in detail today. What I need to know is what forcings the climate system will experience in the coming decades, that will give me an idea, a sense of what the climate will be like, and its volatility, and the weather and its volatility, in 50 years' time. And in that, of course, will be things like natural climate variability, which is essentially what we're talking about when we talk about "What's it going to be like this summer?" - we're actually talking about "What's the natural variability of the system going to do?" So they're very different ways of looking at it.

Jim al-Khalili: Now, people who are sceptical about climate change point to something that's been happening for more than the last ten years, or rather, not happening.

Julia Slingo: Mm.

Jim al-Khalili: The global average surface temperature of the planet has not risen for over a decade, How can this be explained, if the world is supposed to be warming? After all, emissions of carbon have been rising unabated during that period.

Julia Slingo: Well, it's a really interesting question. Again, it requires us to look more deeply into our science, which is what we've been doing, for the last two or three years. And what we increasingly think now is that of course the ocean does take up most of the heat that the planet's accumulating, because we've put all this additional carbon into the atmosphere - the greenhouse effect. And that 90% of that additional heat goes into the ocean. The ocean is a fluid and it moves. And it moves that heat around the system - not just horizontally but also vertically, from the upper layers of the ocean to the deeper layers of the ocean.

And what we have seen, of course, is that if you look at the pattern of temperature change, over the last decade, also, that there isn't uniformly a slowdown. There's actually a pattern of cooling, absolute cooling in the Pacific, that has a structure that tells us that it's the motion of the oceans that has changed, and that in so doing, the ocean has moved heat from the upper layers to the deeper layers. In other words, the heat that we would, in a simple world, have expected to still be manifested in the surface temperature - what we use as a metric for global warming - hasn't gone away, but it's now deeper into the ocean - we don't see it at the surface, it doesn't mean it's not there.

Jim al-Khalili: And did climate models predict that this would happen?

Julia Slingo: Yes, these models have these periods of slowdown. And they'll simulate what we call the Pacific Decadal Oscillation, which is what I'm talking about here, changes in the Pacific Ocean. We hadn't, I think, looked at them in great detail, because they are just part of the natural variability of the climate system. I don't think that we had fully understood the degree to which variation on these decadal and longer time scales, how much that would influence the global surface temperature.

Jim al-Khalili: And, and do we know, can we project, can we reliably say how long this flattening of the global temperatures will last, now?

Julia Slingo: It's very difficult, I mean, if we look at the past record - we've got about 100 years of reliable data - and the Pacific Decadal Oscillation really has a time scale of 20 years or so, how many have we sampled in 100 years? We've sampled about two, maybe three cycles. So we don't really know an awful lot about it. So it's going to be very hard. We can, of course, start to look now at our shorter-term - in this case, really are predictions, that take the current state of the ocean and the atmosphere, and carry that forward in our models, and say "What are they telling us about, say, in the next five years - are we going to see the end of the pause, or are we not?" And that work is very much at the cutting edge of our research, at the moment. And I think, to be honest, I'm not going to tell the listeners what the answer is just yet! [They laugh.]

Jim al-Khalili: Don't want to be held to it... Now, according to some of your former colleagues from Reading University, you've been on a crusade to give more researchers access to more powerful computers. Here's Professor Sir Brian Hoskins, Director of the Grantham Institute for Climate Change at Imperial College London, and, first, Lesley Gray, Professor of Atmospheric Physics at Oxford University.

Lesley Gray: She's really fought for getting improved computer facilities for the whole of the UK meteorological community. So we now share computing facilities with the Met Office - we run the same models on the same computer, sharing data and we work together so much better than I think we were 10, 15 years ago.

Brian Hoskins: Julia has certainly taken the computational power - both at the University of Reading and very successfully, recently, the Met Office - as one of the things she sees as an essential ingredient for that institution to carry out the research that they need to do, if they're going to benefit the science, and humanity. So she's identified this and says "This is what is required - I'm going to fight like a tiger for that, in all ways I know how".

Julia Slingo: I think I've always been somebody who's felt that if it feels right, and it's needed - whatever it is in life - I'll fight for it. For me, it was just really important that this science, which is so vital for humanity - well, the world, really - deserves to have, effectively, the laboratory, if you like, so that we can do the best possible job. We, as a society, must invest in those sorts of things - in the same way we invest in schools and hospitals, we do need to invest in understanding where we're taking this planet.

Jim al-Khalili: In 2008, Julia Slingo, you were appointed Chief Scientist at the Met Office, the first woman in the post. And you were due to start the job in October of that year. But then something terrible happened in your personal life. Can you tell us about it?

Julia Slingo: Yes, well, sadly, we were on our way home from our 30th wedding anniversary holiday, with our two daughters, and my husband collapsed and, ultimately, died in Los Angeles, on the way home. So...

Jim al-Khalili: Heart attack.

Julia Slingo: Heart attack, and very, very shocking and completely and utterly unexpected. He was a fit, well man. And yes, I came home without him. But he'd said to me, when he was first taken ill, that I must do the job I'd...

Jim al-Khalili: Did you consider not taking the job, after this? Many people, quite understandably, might decide not to. I mean, just - simply just being in this shock and grief of losing their life partner.

Julia Slingo: Well, he - we - before he finally died, we had talked about it, and I'd, sort of, said "Well I - I'm not going to - I'm going to pull out, because I need to look after you". And he was absolutely adamant that I shouldn't do that, that I'd earned this job. He felt it was the right job for me to do, and we would work it out. In the end, of course, he didn't survive, and I came home and felt, you know, that he would be disappointed if I didn't give it a go. And also for my daughters' sakes - who were, themselves also devastated by losing their father - at the thought that I would just sit at home and grieve, was not something they wanted, and they knew that i had more in me, I think, to give.

Jim al-Khalili: You also had several controversies and critical situations to deal with, in that first year. There was the media scorn over the Met Office forecast for a dry, warm summer, which was anything but. There was the volcanic ash cloud from Iceland, blowing into UK airspace, the disruption to air travel that caused. And of course there was the Climategate email controversy at the University of East Anglia, which prompted this wider public questioning of trust and openness in climate change research. Which of those was the hardest challenge?

Julia Slingo: Well, I started, I guess, with Climategate, and that was the first time I'd appeared before a Select Committee. I think, in the end, it was - it was good for us, because out of that I insisted that we - we had to be much more open and transparent in our science and our data. And I've achieved that, so that was a good outcome.

Volcanic ash, of course, we went from being probably the least experienced volcanic ash advisory centre in the world to the most experienced, in two weeks. And, you know, we had to deal with airlines that were absolutely insistent that there was no ash up there, 'cause they couldn't see it, but that was quite exciting, because in a sense it was science of the moment, and we were having to do research, turn it round in a day to get new answers for the airline industry.

The "barbecue summer", of course, was I think a failed bit of communications, in a sense, because actually what we really said was that it was "odds-on for a barbecue summer", that we were actually forecasting a warm summer - which it was - and rainfall we weren't sure. But we tried to make it a bit more relevant to the public, and I think came unstuck.

Jim al-Khalili: Can we move on, Julia, to the criticism - and worse - from some quarters, that you've been the subject of, as most senior government scientist in the area of climate change - here are Oxford's Lesley Gray and Brian Hoskins at Imperial College, again.

Brian Hoskins: All of us who come out in the climate change area, we are speaking on the basis of our science, but the implications of that science are huge, in political terms, in policy terms, in energy, in much of what we do. So we speak based on the science, but the implications there mean that there will be people sniping at us and trying to undermine what we do. And Julia, being a government employee, is particularly exposed in that.

Lesley Gray: She doesn't have a natural thick skin, but I'm sure she's grown one. And in some ways the obviously inexcusable comments like this "Julia Slingo woman" are easy to brush off. But there's an underlying drip-drip-drip of little comments that make it quite tough, even now.

Jim al-Khalili: Julia, have you had to grow a thick skin, in the job?

Julia Slingo: Yes, definitely. I kind of knew that I would have to, when I took the job, that this would come with a lot of public exposure. And you just learn to have sloping shoulders, I suppose. But at the end of the day, you just have to get on with the job, because it's such an important job, and it is absolutely imperative that the science is communicated with absolute robustness, integrity. People may not like what I say sometimes about the science, because it doesn't suit them. But it's never going to stop me saying it.

Jim al-Khalili: On the other hand, when it comes to people who are critical of the climate models, they would argue that, you know, being sceptical about the predictions of a scientific theory is a healthy and necessary part of the scientific method. Particularly, I guess when it comes to something as complex as climate science. Don't the sceptics ever have good points to make?

Julia Slingo: What they forget is that a scientist is always sceptical. You look at what your results are telling you, you're looking at your model, you're questioning and questioning and questioning it, all the time. That's the process of research. So to suggest that somehow we're not sceptical is just not right, really. So, yes of course I'm sceptical, and I'm sceptical about the models in the sense that I understand their limitations, but I also know their strengths. And, you know, when we say something about climate change and the direction of travel for this planet, we're saying it knowing both the strengths and the weaknesses of the models we're working with. But there is nothing out there that makes me believe, or even begin to suspect, that warmer air doesn't hold more water, that you trap infra-red thermal radiation in the planet that the planet won't warm. And at what point do you need to be sceptical?

Jim al-Khalili: Getting to the "this Julia Slingo woman" remark, this was a description of you by Nigel Lawson, Lord Lawson, the former Chancellor of the Exchequer, which was reported in the Guardian newspaper. He was commenting on your "absurd statements" - these are his words - in which you suggested there was likely to be a link between climate change and the persistent heavy rain, storms and flooding that many of us in the UK experienced over the winter. The BBC reported you as saying "All the evidence suggests there is a link to climate change". Is that what you said, and do you stand by it?

Julia Slingo: That was taken out of context. What I actually talked about was the fact that again, back to fundamental physics - if the air is warmer, it holds more water. So a weather system today will hold more water than the same weather system would have done 50 years ago. If it holds more water, and when it rains it brings out that water, you'll get heavier rainfall. That is well understood, it's observed - it's hard to detect yet in our observations in the UK, 'cause we have such a volatile climate, but it's seen around the world. So all the evidence points to, as we go through global warming and for the warming we've experienced, we are going to get more rainfall. I had some other points that are related to that, which are more nuanced, but those are the points I was making.

Jim al-Khalili: Weren't you running the risk of ascribing a single weather event to anthropogenic man-made climate change, which of course is something that no-one can do?

Julia Slingo: I was talking about the weather over the winter. So I wasn't talking about one particular storm. Because of course the weather will always do what the weather wants to do. But what climate change does is adds that little bit extra to each of those weather systems, in some way or other. And so what we were actually talking about was, if you like, the extreme weather in the round that we saw this year. So if we go to the IPCC Working Group II report that was published last week, that is a message that comes through that report time and time again, that extremes are getting more extreme.

Jim al-Khalili: And just on Nigel Lawson's comment referring to you as "this Julia Slingo woman", how did that affect you? How did that make you feel?

Julia Slingo: Actually, surprisingly it didn't bother me, in the sense that it was just so unnecessary, so unpleasant, actually quite sexist, I thought it reflected more on him than on anything that I was doing. It almost, I think, was almost a reaction to the desperation of the situation he had got himself into, in the sense that the science base and the evidence base now is so strong that resorting to personal abuse said as much about him as anything that I might or might not have done.

Jim al-Khalili: What are the worst things, the sort of things that people have said about you, to you?

Julia Slingo: I'm not going to tell you, but some of them are truly terrible, and they have broken me on the odd occasion. I have, on occasion, met one or two of these people quite deliberately afterwards and looked them in the eye and said "You know what you did to me was unacceptable", and they generally have apologised. They are enough to be libellous, actually - I could take people to court, for what they've said. But for what purpose, at the end of the day? It would just use my energy, whereas I think my job is to keep fighting for the science, keep trying to do the best science we can, make sure I've got the supercomputers to do the best science that I can, and communicate it.

But actually what really bothers me is that I look at all the tens of thousands of scientists around the world, who work in a very dedicated and often very self-sacrificing way to further particularly climate change science. And they deserve better than to be got at and criticised in this way. I mean, we - the profession of a scientist is almost like the Hippocratic Oath, is about honesty and truthfulness and searching for the truth or knowledge, increasing your knowledge. It's not about making money, it's not about winning research grants, it's not about self-promotion. The majority of us is all about seeking for truth and communicating the truth to the best of our ability.

Jim al-Khalili: Julia Slingo, thank you very much for sharing your life scientific.