20130827_JH

Source: BBC Radio 4

URL: http://www.bbc.co.uk/programmes/b038xrj5

Date: 27/08/2013

Event: The Life Scientific: Joanna Haigh

Credit: BBC Radio 4

People:

• Jim al-Khalili: Theoretical physicist, author and science communicator
• Alice Bows: Senior Lecturer in Energy & Climate Change, Manchester University
• Joanna Haigh: Professor of Atmospheric Physics, Imperial College London
• John Pyle: Professor of Atmospheric Chemistry, Cambridge University
• Yvonne Unruh: Senior lecturer and astrophysicist, Imperial College London

Jim al-Khalili: My guest today works in one of those areas of research that generate considerable heated debate, outside the world of science - climate change. Joanna Haigh is Professor of Atmospheric Physics and the Head of the Department of Physics at Imperial College London, where she studies the sun and the impact of its radiation on our planet's climate. Joanna began her career in meteorology at a time when only scientists were talking about how greenhouse gases in the atmosphere were causing the world to heat up. She's been part of the IPCC, the international group of scientists that produce reports on the state of the world's climate. So, inevitably, she's come up against the climate change deniers, who don't believe that global warming is man-made. This year she was made a Fellow of the Royal Society, one of the highest accolades a scientist can receive, and awarded a CBE for services to physics. Jo Haigh, welcome to The Life Scientific.

Joanna Haigh: Thank you.

Jim al-Khalili: Jo, it's true, isn't it, that the public today don't seem to be so interested in climate change. So, how do scientists engage with society in sensible debates about it?

Joanna Haigh: Well, there does seem to have been a sort of slipping-off of interest in climate change, perhaps because of changes to the economy of the country and people feeling the pinch. But we do try and remain engaged with the public, explaining what we do in whichever media we can, to inform them about our research and what we think is happening to the climate.

Jim al-Khalili: But of course climate change is still an important issue that we need to be concerned about.

Joanna Haigh: Oh, absolutely, more than ever. I mean, we're doing precious little to change the emissions of greenhouse gases into the atmosphere. The temperature is going up and up - it has some wobbles, but we just think it's going to go up and up. And it really is something that we should be thinking about.

Jim al-Khalili: You've been studying the climate your entire career, I guess. But I believe you had an early interest in studying the weather, as a child.

Joanna Haigh: I did - I loved the weather and the sky, and I created my own little weather station, which [laughs] I think accuracy was probably not one of its strong points but it was great fun, and I had a chart and I recorded the wind and the clouds and the rain and... Temperature I had, and pressure, every day for a couple of years, at least. So, that was the beginnings of it, I think.

Jim al-Khalili: What were your findings? [They laugh.] Not that you predicted climate change -

Joanna Haigh: No, I wasn't thinking about climate change. I think, you know, I could do summer and winter, I was probably doing quite well.

Jim al-Khalili: Well, you studied physics at Oxford. Did you enjoy your undergraduate time?

Joanna Haigh: Probably too much. [Laughs.] Had a great time. I might say to our undergraduates today, the balance between your social life and your work is a little bit too much on the social side. No, I had a great time.

Jim al-Khalili: But in fact, after graduating you took a year off. Why did you do that?

Joanna Haigh: Well, I wasn't entirely sure what I wanted to do next, and I had the opportunity to spend a good six months in Turkey and the Middle East, looking at archaeological sites. So I did that.

Jim al-Khalili: That's a huge departure from physics.

Joanna Haigh: I wasn't doing it as a scientist. Well, actually I saw some very interesting weather features, you know, on my way round those areas. I was juts accompanying my partner, who's a historian.

Jim al-Khalili: Well, your interest in climate and the weather was there, dormant, but you ended up going back into that area of science.

Joanna Haigh: Yes, so coming back from that tour, I was thinking what I wanted to do, and I found that there was Masters courses in meteorology available. And I thought: wow, yes! That's definitely the thing for me. So I went to Imperial College to do the M.Sc in meteorology and just loved it.

Jim al-Khalili: And then back to Oxford for a Ph.D.

Joanna Haigh: That's right. So, back to Oxford for quite a sort of theoretical - you could see quite dry - Ph.D in radiation transport in the atmosphere. But when you understand why you're doing that, and it's got applications in climate and the environment, then, you know, it just becomes really exciting.

Jim al-Khalili: Well, at Oxford - this is in the late '70s - you then worked with John Pyle, who's now a Professor of Atmospheric Chemistry at Cambridge University.

John Pyle: Joanna and I met in the late 1970s, when she started a D. Phil. in Oxford, and I think I'd just finished mine, in the Department of Atmospheric Physics. We worked together on a problem to do with stratospheric ozone, and we did some, I think very nice work in the very late '70s, early '80s, where we pointed out the mutual interactions between - if you like - the chemistry system and the climate system. She's one of the major experts on solar variability, and the impact of the solar cycle on climate, so she's been a very influential person in that regard. She was just a very nice person to work with, we enjoyed each other's company - I think we talked about politics quite a lot, it was the time when politics was much more polarised, in some ways, than it is now, and we talked and argued a lot about politics, which was fun.

Joanna Haigh: Not too much argument.

Jim al-Khalili: You -

Joanna Haigh: Lots of discussion, yes.

Jim al-Khalili: And, at that time, there was - we're talking about 30 or more years ago - what was known about the climate and how it was changing?

Joanna Haigh: So there had been work on what causes climate change, there'd been a big conference in, I think, the mid-1960s, on the causes of climate change. But there wasn't any real understanding of global warming, in the sense that it's understood today. I think the real thing that was going on was advances in computers, and so that we were able to develop computer models, to study things that really were too complicated to try and do, you know, on the back of a bit of paper. And we were able to create computer code to understand how the radiation, the chemistry and the winds all interacted.

Jim al-Khalili: It's a very complicated subject - you know, people very naively talk about: carbon dioxide raises the temperature. And we're going to talk about - unpack it a bit more later on, but this is an early sign that there's so much involved in the Earth's atmosphere.

Joanna Haigh: Yes, and I mean, what I've just been describing is really rather a sort of simple part of it. If you try and put in all the weather and the clouds and the rain and everything else, the whole thing becomes very complex. I think part of the attraction of working in this area is that it's - I mean, not just that it's the real world, but also it's such a complex system, it's always giving you surprises and, you know, you can never get bored.

Jim al-Khalili [laughs]: Well, let me try and get some of the basics, sort of foundations of the science down, first. The sun's rays hit the Earth and the atmosphere reflects some of that radiation - light and heat - back out into space. So it's not surprising that the temperature on Earth depends on the composition of the atmosphere. So, if the levels of greenhouse gases, like carbon dioxide or methane, go up, that's going to affect the temperature.

Joanna Haigh: That's right. So, essentially, most of the solar radiation heats the surface of the Earth - it gets through the atmosphere, so the atmosphere's fairly transparent to visible radiation. And the surface gets hot and emits heat radiation, but because of the greenhouse gases, that heat gets absorbed and so traps, like a blanket, into the atmosphere. As there are more and more greenhouse gases in the atmosphere, this thickens the duvet and keeps the surface of the Earth warmer. However, those gases don't affect the transmission of solar radiation, which carries on warming the surface of the Earth.

Jim al-Khalili: And that solar radiation isn't constant, is it? That the heat and light from the sun is variable as well.

Joanna Haigh: That's right. We know now that actually the amount of energy coming out of the sun does vary.

Jim al-Khalili: So this variation - is this what we refer to as solar cycles?

Joanna Haigh: Indeed, so the one that's most commonly known is the 11-year sunspot cycle. And we now know that the radiation varies by perhaps a tenth of 1% over the solar cycle. But that's enough energy to, potentially, have a small influence on surface temperatures of the Earth.

Jim al-Khalili: And, of course, what we want to discuss is just what fraction of the Earth's climate depends on variations in the energy we get from the sun. Now, your research looks at how different wavelengths of sunlight affect different layers of the atmosphere in different ways.

Joanna Haigh: Exactly that. The sun is radiating at a temperature of 6,000 Kelvin, which means that the peak of its spectrum is in the visible, so humans' eyes have adapted to visible radiation, which is most of that, coming from the sun. But it has a whole spectrum, going right the way from X-rays through ultraviolet through near infrared, right the way through to long microwaves. And each of those wavelengths will be absorbed differently by the atmosphere, depending on the composition of the atmosphere.

Jim al-Khalili: And you published two landmark papers in the mid-'90s, in the two leading academic journals, Nature and Science. What were your findings?

Joanna Haigh: So in the Nature paper I was looking at how solar radiation is transmitted through the atmosphere, and I realised that because the sun varies more at ultraviolet wavelengths than it does at visible wavelengths, it will disproportionately affect stratospheric ozone, which is both created and destroyed by UV radiation. This, in turn, heats the stratosphere, and that affects the greenhouse effect and the radiation reaching the Earth's surface. It also influences the winds, and thereby we can see the effect on the surface.

Jim al-Khalili: So that's the important thing, isn't it, because we think about the sun's light, the different wavelengths affecting different parts of the atmosphere, but you're saying it affects one part of the atmosphere more than another, and that changes the direction or the strength of the winds like the jetstreams.

Joanna Haigh: Yes, so what happens is that as the stratosphere heats up, this changes the temperature gradients - you know, the horizontal variation in the temperature in that region - and that affects the dynamics in the winds in the atmosphere below. And in particular, what I found in the Science paper was that when you heated the lower stratosphere, the jetstreams moved very slightly more towards the Poles. So, a small shift in the jetstreams. Now, in terms of a sort of global average picture, that's tiny. But if you happen to be, you know, sitting in the north of Scotland with your weather station, and you've been recording temperatures and winds and precipitation over many, many years, and you think you've been seeing an 11-year solar cycle, and you've been treated as a crank, perhaps you weren't. [Laughs.] Perhaps there really is a signal, that's seen particularly in regions that are affected by the jetstream.

Jim al-Khalili: And were your ideas, in these papers, immediately accepted?

Joanna Haigh: Not s- I think the Nature one was okay but the Science one made quite a big impact. Yes, I think so.

Jim al-Khalili: In what - in as much as it was controversial?

Joanna Haigh: I suppose it was slightly controversial, but I think it made a point that hadn't really been properly considered before. And it made people who were doing the big climate models think "Oh, perhaps we should take the UV into account", which they'd never done before.

Jim al-Khalili: Well, that's an interesting point, because I was going to ask you: why is this work important, in terms of understanding climate?

Joanna Haigh: I would never say that the sun is more important than the greenhouse gases in affecting the surface temperature on the sort of decadal timescales. But there are perceptible differences, and only by understanding those can we sort of extract them out and understand what the greenhouse gases are doing.

Jim al-Khalili: And presumably it's also useful for meteorologists, so that they can make accurate forecasts of the weather next week or next month.

Joanna Haigh [laughs]: Um, that's also, um, quite controversial - so there's a lot of discussion now on weather, how good the stratosphere needs to be in weather forecasting models, and I think the jury's out, on that one. I mean, all the work I've done is more on, sort of longer than yearly, more like decadal timescales. Of course, the problem with weather is that it's so noisy and variable and - at least with climate, we can look at averages over months or seasons, and things look a bit easier to understand. Whereas if you're trying to do the weather in the next few hours or the next few days, are you're trying to do precisely what it's going to do over London at 10 o'clock on Tuesday, everything's much more complex, and the noise in the system is much bigger. And small changes in the stratosphere, it's - it's difficult to think they're going to have much of an impact.

Jim al-Khalili: That's interesting, because you're suggesting that predicting what the global climate's going to be like, 20, 30, 50 years from now is somehow more reliable than predicting next week's weather.

Joanna Haigh: I don't know about the dates that you've given [laughs] -

Jim al-Khalili [laughs]: I just randomly chose -

Joanna Haigh: I do think that. If you're looking at large areas and long time scales, the physics is simpler, it's less complicated. Of course, you have got big uncertainties in those things, big error bars in your predictions, but, you know, you're not trying to look on the small time scales and the hour by hour time scales that are - you have to do for the weather forecasting.

Jim al-Khalili: When we hear about climate scientists having to improve their computer models, what they're doing is adding extra bits and pieces into a pre-existing calculation. And how reliable can you get with these models? Can you ever really have a realistic mathematical computational model of something as complicated as the Earth's climate?

Joanna Haigh: Well, I think you've got to decide what you mean by "climate". So if you look at - well, for a start, if you just look at global atmospheric temperature, we can do it pretty well, I mean, very accurately. Then if you start to look at the different sort of weather patterns the models can produce, the seasons, the storm tracks, the monsoons, um... cloud distributions, it is quite amazing that you can write down a few equations, put them into a computer and come out with something that really looks pretty much like the real atmosphere. I'm still amazed, actually. But of course then you've got to say: well, if you want to do experiments in changing the climate, how good is the physics in the model that you can actually then tweak it and get out something that you think is realistic? So, you can test that in various ways. You can do historical runs, where you put in changes in greenhouse gases and changes in the sun that you know have taken place over the last decades, and compare the results with observed temperature distributions. And we can do those pretty well, too. Again, it depends on what sort of scales you're looking at. If you looked at very, very small scales, we wouldn't be able to do every region of the world properly, but if you're looking at large regions - you know, just north or mid latitudes or tropical sort of regions - then it does a pretty good job. So you think: well, there must be something right about the physics, in that we're doing that, and that gives us some faith in predicting the future.

Jim al-Khalili: Now, you've been part of the IPCC, the Intergovernmental Panel on Climate Change, which is the organisation that produces the highly-publicised climate reports every few years. Do you think the IPCC, on the whole, is doing a good job?

Joanna Haigh: I think it's doing a fantastic job. I mean, you can't imagine the work involved. [Laughs.] There's several misconceptions about the IPCC. One is that it sort of does work and reports on it. That's not the case, it's there to review work that has been published in peer-reviewed scientific journals. So it's not doing any of its own work. And then you have the panel, and it meets intermittently over a period of perhaps two or three years, collating all the information, discussing it, digesting it, assessing it and producing this report. Which is then reviewed more heavily than any scientific paper you could ever imagine being reviewed. It goes out for three or four stages of review and at each stage the panel - whose writing has to provide a response to every single comment that's made, even something that's completely stupid, you can't say "That's stupid", you have to say "I think this person has missed the point, because...". And you can imagine hundreds and hundreds of referees' comments - it is a huge amount of work.

And the idea that the IPCC is some sort of consensus body of mad green scientists, who are all trying to have their own agenda, work through government, or something like that, is quite ludicrous. I mean, you know what it's like when you put a load of scientists together in a room, they're not going to decide to agree with each other, in fact they're each going to try and be clever and disagree with each other. So consensus is very, very hard to achieve. And the fact that they come up with some sort of general agreement means you can be pretty sure that that's been worked through well.

Jim al-Khalili: Because, of course, a climate change sceptic will say that those who review the IPCC reports are -

Joanna Haigh: Part of the club.

Jim al-Khalili: - part of the club.

Joanna Haigh: Yes. Have to say, I slightly object to the use of the term "sceptic", because there's absolutely nothing wrong with being sceptical - all good scientists are sceptical. So I tend to refer to those people you mean as "climate change deniers". Because they just deny it's happening and choose various reasons.

Jim al-Khalili: What is the current consensus, then, amongst scientists about how our climate is changing? Are we doing enough to avert a potential disaster in years to come?

Joanna Haigh: No, not at all, no. I mean, precious little. [Laughs.] All the signs show that unless we do something more radical, the temperature is going to carry on increasing. Of course - and there's been quite a bit of controversy, over the recent months, because the increasing trend of the temperature seems to have flattened off a bit, and that has given succour to some of the climate change deniers - "Oh, you see, it's all gone away". But I don't think that's the case at all.

Jim al-Khalili: This is the research that was published a few months ago that says that if, you know - the calculation that says: if you double the amount of carbon dioxide, how much would the temperature go up?

Joanna Haigh: Yes.

Jim al-Khalili: And it was thought to go up to 3 degrees, and now they're saying no: only up to 2 degrees.

Joanna Haigh: Um...

Jim al-Khalili: Suddenly that's not so bad.

Joanna Haigh: Well, there was always large error bars. In the future, of course, as we've already discussed, it's a complex system and

you're not going to get, sort of, one particular value, so there's uncertainties and there's always a range of temperature around which it might go up. But you can see, if you look at the temperature record over the past, sort of, 150 years, it wobbles, it doesn't just go smoothly up with carbon dioxide, it wobbles around all over the place, and there's been various hiatuses in the past. And there's a hiatus now, and I don't think everybody should be getting very excited about it, and to thinking "Oh, it's all right. We don't have to worry about climate change after all".

Jim al-Khalili: Well, one of your colleagues at Imperial College, Dr. Yvonne Unruh, admires the way you've engaged with climate sceptics.

Joanna Haigh: Oh, thanks, Yvonne. [Laughs.]

Yvonne Unruh: When I first started working in the field, I was quite shocked by the acrimonious comments you might get on some of your work. And people taking it out of context, perhaps, or just picking bits and pieces and being quite vociferous, and sometimes rather rude about it. While you're very used to defending your work to other scientists in the same field, and you're all speaking the same language, here that was quite a shift for me, and so it was interesting to see how she copes with it, and how she deals with it. I quite admire her oomph and, yeah, her willingness to put her neck out.

Jim al-Khalili: How acrimonious has it been, then?

Joanna Haigh: Um... well, of course, much of this stuff is done on the internet, so - I do get some personal letters but most of it's done by people writing rude things on blogs, and things. And, um, you know, ugly cartoons and that sort of thing. I think, you know, you just ignore it. If people write to me personally, I always reply and I try and explain what I think they've got wrong and what the real situation is.

People are quite surprised - quite often surprised that I've written a polite reply. And quite a few times I've had replies that say "Well thank you very much for your", you know, "You've taken the time and the care to reply to me, but I still don't believe it". So, you know, you lose, but you try and engage.

Jim al-Khalili: And it is difficult for the wider public to know what to believe. As you say, so many people are writing blogs, there's so much out there. You know, who do they listen to? Who do they - who can they trust? And when it comes to education, there's recently been changes to the English school curriculum. Do you think there's enough taught about climate change?

Joanna Haigh: Well, there's considerable controversy about that, because there was a suggestion that climate change was going to be dropped from the Key Stage 3 Geography syllabus, which we - I say "we", as in the Royal Meteorological Society - tried to argue against. I don't know what decision they'll come to, but to, sort of, present climate in separation from any discussion of changes that are going on, seems quite silly. In addition to which, most schoolchildren are aware, nowadays, of climate change, so if they're not being taught about it in geography, or indeed in science, what are they meant to think?

Jim al-Khalili: And, of course, if you ask most children if you're going to be a scientist, what sort of thing do you want to do, so many of them say they want to change the world or make a difference -

Joanna Haigh: Yes.

Jim al-Khalili: - they want to work in environmental science or climate change.

Joanna Haigh: Some do, yes. Yes, yes.

Jim al-Khalili: Where do you think the next generation of atmospheric physicists are going to come from, then?

Joanna Haigh [laughs]: I don't know, actually. It's interesting, isn't it. At Imperial College we get some fantastic physics students, undergraduates coming in, aged 18. At interview, a large proportion of them want to do particle physics - of course it's very exciting, with the Higgs Boson and all this sort of thing - or cosmology, and of course that's right and proper. But, by giving them a very broad education in physics, sometimes we extract some of them wanting to do atmospheric physics [laughs.]

Jim al-Khalili: Of course it's one thing developing these computer models to predict how the climate is changing, but satellites have really transformed the nature of research in this area. How have they helped your work?

Joanna Haigh: Absolutely, well I was very lucky to be in Oxford in the late 1970s, where John Houghton and his group had instigated new instruments on satellites, that were then being used to look at all the different aspects of the atmosphere, its temperature and composition. So it was a great place to be working. The sort of satellites that I've been interested in are the ones that are measuring solar radiation, both the total energy coming out of the sun, which we call total solar irradiance, and also the spectrum of the sun's radiation - and as you know I'm particularly interested in the ultraviolet region. So satellites have transformed the science, I mean, without the measurements of the solar radiation, I wouldn't have been able to do the work that I've done.

Jim al-Khalili: And you need the satellites up there, carrying out those measurements, because it's impossible to do it from -

Joanna Haigh: That's right. You can't -

Jim al-Khalili: - the ground.

Joanna Haigh: - do it from the ground, because of the interference of the atmosphere. It's just too noisy and too - you know, too much blowing around and getting in the way.

Jim al-Khalili: And what would you say is the future of your own field, studying the sun's variability?

Joanna Haigh: As I've already mentioned, I think the changes in the sun are very important. And so clearly we need to keep measuring what's going on, on the sun, from the satellites. Now there's been a continuous record - different satellites but overlapping records - of measurements of the solar irradiance since the late 1970s. And the current instruments that are measuring total irradiance are on a very old satellite that's just about to expire. Unfortunately, the one that was meant to take its place failed to make orbit, and so -

Jim al-Khalili: It crashed...

Joanna Haigh: Er, well it went up and then blew up in the sky. So it's not doing the measurements. And so there's a gap between the next satellite - between - as soon as these ones, which are getting a bit old now, give up, and the next satellite, which is due for launch in 2016. And this is a real issue, because if these records are not inter-calibrated then you can deduce anything you like about changes in the sun and how it's influencing the current temperatures. I mean, it really is, because the absolute accuracy of the measurements is just not good enough to compare with the big gap between -

Jim al-Khalili: Oh, I see - so by inter-calibrating them, you'd need them both at the same time -

Joanna Haigh: So you need to inter-calibrate them, you need to overlap them.

Jim al-Khalili: So - so you can see that they're in agreement.

Joanna Haigh: Yes. So we've been doing some work on how to fill the gap. Fortunately, it looks like NASA or NOAA, or an American agency, are going to launch a gap-filling mission, so we may be okay.

Jim al-Khalili: Now then, you've been head of one of the largest physics departments in the country - and one of the most prestigious in the world -

Joanna Haigh: Thank you.

Jim al-Khalili: I'm guessing that keeps you rather busy, and possibly away from your research.

Joanna Haigh: It does, rather, yes [laughs]. So it's been a huge honour, and I'm enormously proud to have been the Head of Physics at Imperial. And I've learned such a lot by doing it and really enjoyed it, but it is a huge amount of work and the research has suffered. And so it's a five-year sentence. I will be finishing within the next year or so, and hope the research will, sort of, get on the up again.

Jim al-Khalili: But are you still able to keep your hand in?

Joanna Haigh: I keep it ticking over, I've got a lovely student, a lovely post-doc, and that's about the limit of it, at the moment.

Jim al-Khalili: Well, here's one of your previous research students, Dr. Alice Bows, who's now at the University of Manchester, talking about your informal style, as a Ph.D supervisor.

Joanna Haigh: [laughs]: I wonder what's going to come up now!

Alice Bows: I was applying for my Ph.D and I'd had an interview with Jo, which I thought had gone okay. But what really appealed to me was her slightly less formal and more inclusive and friendly style. So I received a letter and, if I recall correctly, it had the word "stuff" in it, when she was talking about the kind of things I would need to sort out, and which I'd need to do when I actually arrived at Imperial. So you never felt, sort of, very hierarchical, in that sense, it felt very inclusive and the group was really a good place to do research in a really supportive environment, and I think a lot of that was largely down to Jo. You know, physics did, and still does, tend to be quite a male-dominated discipline area. There was much more traditional male attitude, within both the department and also in the field in general, at the time. And so Jo was really like a breath of fresh area, really. And it's a quite intimidating environment that you could find yourself in, particularly as a newer researcher, and particularly for female members of staff. So she was very encouraging and supportive from that point of view.

Joanna Haigh: Well, thanks, Alice!

Jim al-Khalili: And has this informal approach of yours that Alice mentions, been an asset to you in running Imperial College's physics department?

Joanna Haigh: Hey well, that's a good question. Um, I hope so, in the sense that I feel I can talk to people, and I hope they feel they can talk to me, ans that's - more engagement is always a good thing. On the other hand, if they think I'm a bit lightweight or not serious, perhaps that's not so good [laughs.] I'm not sure.

Jim al-Khalili: You have to get tough, when you need to.

Joanna Haigh: Sometimes, yeah.

Jim al-Khalili: And being involved, over your career and research that impacts on climate change, means, as we've discussed, that you're used to engaging with the public, with the media, with politicians, about your science. But given it's such a politically charged - um, and still controversial - topic, are you sometimes envious of other physicists, you know, who work in cosmology or particle physics, say?

Joanna Haigh: Yes, yes. Intermittently, I just sigh and think I wish I wasn't doing this, and it's such a waste of time, writing long letters to people who aren't going to appreciate it or believe what you say. And then I think: well, perhaps I should just become a solar physicist, and understand the sun instead, and then it's not so controversial. But, no. In the end, I think I've enjoyed what I've done, I hope to carry on doing it for a bit longer and - no, I don't want to change.

Jim al-Khalili: I think it's a sure sign that The Life Scientific is good at picking winners, because you've been on our guest list for some time now, I should say. Certainly before this exciting year that you've had - because you were elected as a Fellow of the Royal Society and honoured with a CBE in recent months. You know, we sort of almost knew that was coming. That must have been very exciting for you.

Joanna Haigh: Well, it was, I was completely amazed. And, you know, I think perhaps I should just retire now, because it isn't going to get any better! [They laugh.]

Jim al-Khalili: Jo Haigh, thank you very much for sharing your Life Scientific.

Joanna Haigh: I've enjoyed it. Thank you.