The Life Scientific: Lucy Carpenter

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0:30Lucy Carpenter:at Whole Foods Market. Don't play games with us. A vicious gang of hackers causing chaos for businesses, councils and hospitals. What if I don't finish this treatment and this cancer grows? But they didn't care. I'm dying laughing. Making outrageous demands for money. They wanted millions. It was high tech and high stakes. The country's under attack. And it was highly secretive until someone exposed it all. Cyber hack season four, The Conti Files. Listen on bbc.com or wherever you get your BBC podcasts.

1:07Hello. We begin today in the mid-Atlantic, on the island of Sao Vicente in Cape Verde, a place of trade winds and lava fields where the air blowing inland has spent days travelling over open ocean. Clean air, the kind that atmospheric chemists dream of. Atmospheric chemists such as Lucy Carpenter, professor at the University of York, who studies how chemical interactions impact our climate. Lucy was one of the founding scientists behind the Cape Verde Atmospheric Observatory, established on Salvicente in 2006. It was measurements at this site that paved the way for a significant revelation that ozone loss is not only a human-made problem, the chemistry of the sea has an impact as well.

1:51She discovered that for various reasons, the ocean actively changes the chemistry of the air above it, and in doing so can influence ozone, methane, aerosols, clouds, and ultimately the climate itself. Today, the Cape Verde Observatory has become one of the world's most important atmospheric study sites, while Lucy's career has taken her from that remote island to co-chairing the scientific panel for the Montreal Protocol, the ongoing international agreement to protect our planet's ozone layer. From measuring the chemistry of ocean air to helping turn the tide of global environmental policy. Lucy Carpenter, welcome to The Life Scientific.

2:28Thank you, Jim. Now, you're an experimental atmospheric chemist, so rather than computer modelling from afar, you go out and measure what's actually there. That's right. So often we have to develop or build atmospheric equipment, scientific equipment, because it's not available out there. You can't go and buy something off the shelf to measure tiny radicals at concentrations of less than one parts per trillion. So we often get involved in instrument development as well. And yes, go out into the field and measure it there and then. I suspect most of us think of the ocean as something that's affected by the atmosphere, warming, acidification, pollution, and so on.

3:03But your work flips that on its head, doesn't it? It shows that the oceans are actively shaping the chemistry of the air above them. So what's going on? You're absolutely right. We think of the ocean as this sparse sink of things like CO2, carbon dioxide, but it does emit gases as well. And maybe that's been somewhat overlooked. It's quite hard to get out there into the open ocean. We all know the ocean's full of salt and there's a whole bunch of marine biology that's quite active. So they can act to produce aerosol particles that can influence clouds and influence the oxidising capacity of our atmosphere as well.

3:36We mentioned ozone. We're going to be talking about it quite a lot today. So it's worth getting a reminder of exactly what it is because this molecule is both a protector and a pollutant, isn't it? That's right. So 90 % of ozone in the atmosphere resides in the stratosphere. The stratosphere is the upper. Is the upper. So that's around 10 to 50 kilometres above our heads. That's not a fixed zone, but depends on temperature and latitude. So that's where the ozone layer is, the protective layer that protects us from harmful solar UV radiation. The troposphere is completely different. The way the ozone is formed in the troposphere is different.

4:10In the stratosphere, it's formed naturally from oxygen photolysis. In the troposphere, it's from anthropogenic pollution mixing together. The stratosphere is sort of from what, from sea level upwards? From the sea level to the stratosphere. Right. And then you get straight into the stratosphere. It's an air pollutant in the troposphere, but also a greenhouse gas, quite a strong greenhouse gas. So a very simple term is ozone is bad at the surface and good in the stratosphere. Well, listeners might remember headlines in the 1980s around trying to restore the ozone layer because scientists found this hole above the Antarctic.

4:42So how is that going? I mean, the amazing thing is only two years after the ozone hole was discovered, the Montreal Protocol was signed and then began a phase out of those harmful chemicals that gave rise to the ozone hole, the chlorofluorocarbons or CFCs that were used in fire protection, deodorants as hairspray. So once the Montreal Protocol was signed, the phase out began. And thanks to that and the efforts of hundreds and thousands of people across the world, we are now starting to see the recovery of the ozone layer. So it's predicted to recover back to 1980 levels by about mid-century, somewhat later in Antarctica.

5:17So, yes, it's a success story and has often been called the world's most successful environmental agreement. There is a twist here, isn't there, that some chemicals that we've used to replace CFCs that don't destroy the ozone layer can still be powerful greenhouse gases. Have we just swapped one problem for another? We have basically gone from ozone depleting gases. The CFCs are very ozone depleting. Then they were replaced by the HCFCs. They contain a hydrogen atom, so they're broken down more quickly. So they're not as dangerous. And then often replace them with HFCs. And most people will have an HFC 134A, for example, in their car as their air conditioning refrigerant.

5:55Many of them aren't actually more harmful than CFCs as greenhouse gases, but some of them are pretty potent. And now really they are being swapped out for shorter lived HFCs called HFOs. Now they may bring their own problems as well. I mean, really, there is no perfect fluorinated chemical that you can put into the environment. Well, we'll come on to possible ways of saving the planet. But just to ease ourselves in, let's hear the start of your story. You grew up in rural Wiltshire with mum, dad, three brothers. What were you like as a kid? A tomboyish, I would say. Off of my bike the whole time, went to a local school and I liked all subjects at school, really.

6:38I didn't really know what I wanted to do, but we had a very excellent chemistry teacher that did those sort of old school demonstrations that perhaps don't happen anymore, you know, selling fire to potassium on water. So I think that got my interest in chemistry going. So that's what I ended up applying to do at university. Right, right. Well, you did. In 1988, you headed off to the University of Bristol. I gather your studies got off to a rather inauspicious start, though. They did indeed. I don't think I was a natural in the laboratory to start with. So on my very first chemistry experiment in the labs, I ended up in A &E because I still have a slight scar, actually, on my finger.

7:17It's where I tried to put a teat on a burette and rather enthusiastically managed to get the glass into my finger. So I was never going to make an organic chemist, someone who was in the lab making chemicals. But I did like the physical side, physical chemistry, the mathematical side. And you say things picked up after that accident. Certainly you ended up graduating with the first. You went on to do a PhD in atmospheric chemistry at the University of East Anglia and then stayed on as a postdoctoral researcher. and this is when you started looking at the effect of tropospheric halogens on ozone.

7:52Now, as you mentioned, troposphere being the lowest layer of the Earth's atmosphere. First of all, perhaps you can explain what halogens are. The major halogens are fluorine, chlorine, bromine and iodine and they exist in a whole variety of forms. So inorganic forms, so for example, we've all probably heard of hydrochloric acid, HCl, through to inorganic halogens which are volatile and exist in the gas phase to organic halogens, also volatile, also exist in the gas phase. So the organic halogens just being those that have carbon in them? Yes, so they can exist in a variety of forms, solid, liquid, gas and a huge variety of reactivities as well.

8:32Well, you got involved with the project to measure organic halogens at Mace Head Atmospheric Research Station on the west coast of Ireland. Yes, so there was an idea that there could be some halogen chemistry in the troposphere. We knew that it would involve, if it was happening, more reactive halogens, iodine and bromine, but really very little was known. So I built a system to trap the halogens and we coupled it to a gas chromatic mass spectrometer, so a well-established way of measuring molecules, and put it on this station. It was part of a big experiment. In fact, I think it was one of the UK's first big consortium field experiments.

9:10So it was a great experience. And lo and behold, we found a much richer mixture of halogens that had been seen before. And at that site, you look out to Macehead and you can see seaweed everywhere. And we saw these strange signatures in halogens, which turned out to be due to the tidal cycle. And not only that, because it was a consortium project and lots of different labs were doing lots of different things. The aerosol people, when it was low tide and daylight, they saw what we used to call bursticles, which were huge bursts of new particles, tiny nanometre size aerosol particles. And it turned out the chemistry linked the iodine emissions from the seaweed to these aerosol particles.

9:53Now we think it's not just happening above seaweed beds, but also over the wider open ocean as well. So you're standing on a windy cliff on the edge of Ireland. how exactly do you go about sampling the atmosphere and actually measuring these halogens? A really key thing is how you sample. If a gas is very reactive, you might need an inlet that's only a centimetre long and a special way of making sure the gas or radical is not lost before it gets into your system. So for some very reactive things, we actually have to put the instrument itself on the roof or on the sampling tower. Other molecules, you can essentially have a great big manifold, suck the air down.

10:27You pump the air in, trap it, concentrate it often, because if you're measuring at that tiny, tiny level, you can't just put something straight through into your instrument. You have to concentrate it until you've got enough of it. Get rid of the things you don't need, like the CO2 and the nitrogen and the oxygen, and then just inject what you want. So that's how we tend to do lots of science. And you're injecting it into this instrument, the mass spectrometer, which tells you what elements, what molecules are in that sample. So the seaweed there was releasing halogen compounds into the sunlight and you're suddenly seeing new molecules being created.

11:04What's the chemistry that's going on there? So the seaweeds, they actually accumulate huge amounts of iodine and bromine sometimes as part of what biologists call the oxidative stress response. So they don't like being exposed to dry, sunny air. They like being in the sea. So when they're out, they actually have a whole reactive chemistry going on and their release of these halogens is part of their response. to get rid of things like hydrogen peroxide from their system. But yeah, the molecules that we're seeing are the chemicals that they are emitting that then react with organic material in the seawater.

11:37And together, those things make these very exotic, mixed organic halogens that we saw. And other halogens that we didn't see at the time, but later found out were being emitted as well. But this was surprising. This was surprising. You weren't expecting to see these molecules. I mean, it was incredible. It was like nature telling us, look, there's a tidal cycle here. You guys can figure out what's going on. So that was nice. But, you know, these molecules are pretty reactive. So the sun comes down and breaks that bond through photolysis, photolytic decomposition. And then once you have that, your halogen atom is split off from the molecule, undergoes other chemistry.

12:11And later, not my group, but other groups found that these tiny particles could grow under the right conditions and they can impact clouds. And then you really are into a climate impact. Well, in 2000, Lucy, you joined the University of York, where you still are now. And so we come to Cape Verde. How did the idea first come about for a research station based there? Well, I was approached by some German colleagues that had the idea of having a station there. The main person who thought about it was an oceanographer. So he was really interested in that region, partly because a whole load of Saharan dust gets deposited in that part of the ocean every year.

12:49and that can stimulate ocean biological processes. So he approached me as someone who was active in this ocean air research and said, you know, we found this station. It would be a great place for you to do your research as well. What do you think? So you go over there to recce the site. Do you remember that first trip to Sal Vicente and what made it such a perfect spot for the station? I do remember it very clearly. At that time, there was a dirt track that culminated in a sort of hut and then a few hundreds of metres away was the site that we were looking at. And it was larval rock, basically extinct volcano because Cape Verde is full of extinct volcanoes and active ones.

13:29But from that site, you could look to the ocean into the prevailing winds. You're looking northeast into the winds. And there, the trade winds essentially bring round air that hasn't seen land for three or four days. And they do that 95 % of the time. There are a lot of stations that want this clean air, but I mean, half the time they don't get it. So it was great for that because it was like being on a ship, really, except for, you know, with all of the things that went along with that. So trade winds bringing in that clean air. And it was in the tropics, which are very few stations in the tropics.

14:00The tropics are great. They're like the engine room of the atmosphere. All of this sunlight and water vapour creates a very rich chemical environment there. And really what we wanted was a kind of station that could be used for shorter term field campaigns, but as a baseline to understand what was going on. You mentioned the hut and the dirt track. This really was site construction from scratch, wasn't it? That's right. We had to put in power lines. We had to put in a base, a foundation. We were very lucky that we had fantastic support from the Cape Verdean Met Office. So they helped us to do that.

14:35And we had to put a lab there. So we got lab containers made in the UK. So we sort of essentially built the lab in the UK and shipped it out. Plug and play, almost. And, you know, working on a remote tropical island might sound quite romantic, but obviously this isn't some sort of paradise holiday resort. What were the biggest hurdles when you were getting the project off the ground? The project got off the ground relatively quickly, again, thanks to the support of the Cape Verdean colleagues. But the main problem with any site like that, very remote, are power cuts. There were constant power cuts.

15:06We put in a backup generator. We had to put in a backup generator to the backup generator. That was a really key thing. And it's, you know, salt, sunlight, everything rusted. We needed very regular painting and very regular protection. And the dust that came down, we had to change our manifolds quite regularly. So it is a harsh environment. But we're really lucky that the technical officer that we employed at the time, with Cape Verdean local, he's still there. So 20 years later, he's still there and he's been absolutely brilliant at maintaining that site. There was a huge storm there last year, wasn't there?

15:41That must have had quite a big impact. Yes, it brought a huge amount of rain, flooded the city. It was actually declared a national emergency by Cape Verde. We got off reasonably lightly. The road was destroyed to the site and there's still a massive hole in that road. So getting there is not easy. We were back up and running in about two months, I would say. We did think it could have been longer than that. But yes, these are the things that happen. You know, you were on the path of massive tropical storms that go past. Yeah, it's inevitable. It was going to happen and it did. Well, the Cape Verde Observatory started collecting data from late 2006 and now it's a World Meteorological Organisation watch site too.

16:20Did you ever imagine in those early days that this would become one of the world's rare long-term atmospheric research sites? I think we had a wish. It was our aspiration that it would be a long-term site. You know, you set something like that up. You don't want it to be a three or four-year project. But as you know, the challenge in the funding environment, no one gives you money for 25 years time. What you have to do is you have to set something up on short-term funding. And we were very lucky to make inroads at some interesting scientific places. Well, in 2008, Lucy, based on your measurements from South Vicente, you published a seminal paper in the Nature Journal, which showed that halogen chemicals were responsible for extensive ozone destruction over the tropical Atlantic Ocean.

17:08Talk me through what that data showed. At that time, we'd seen this coastal phenomena, seaweeds giving halogens. What had never been seen was the coexistence of these halogens and the smoking gun for the chemistry, which is ozone being destroyed. Normally, if you go to most sites, you'll see this is ozone at ground level increasing during the day because the pollution that gives rise to it means that once the sun comes out, ozone increases. So you have to be in this really clean environment to see the ozone loss processes occurring, in this case, the halogens. So we were there and day after day after day, as soon as we started measuring ozone, we could see these daily cycles where the sun came up and ozone was destroyed.

17:52And then it comes up again at night because it's been transported in. We expected that to some extent because it is destroyed by photolysis. But when we applied our models to it, we found that almost twice as much ozone destruction was going on than you'd expect from the traditional chemistry. So we were lucky that we had measurements from the University of Leeds on the halogen oxide radicals. And we were able to quantitatively tie the two together through models and say it's, you know, due to the presence of these halogen molecules, we're getting 40 % more ozone destruction than you would expect without them.

18:24Yeah, and in fact, in terms of the numbers, your data was showing that about 15 % of all ozone destruction was down to this marine effect. That's right, which hadn't been seen before. It was a serious breakthrough, of course, with big implications for existing climate models that hadn't taken into account halogen chemistry. Initially, there was some pushback on this. Yeah, that's right. And now nearly 20 years since then, that whole chemistry screen does exist in models. So over the years, that chemistry has been inputted and shown on the whole that you do a better job trying to simulate ozone if you include this chemistry.

19:00And you certainly will see different results in terms of pollution in the future and pollution in the past. So it changes how we think about how the atmosphere has evolved. And I'm wondering whether part of that initial pushback was about people being nervous that this might play into the hands of climate change deniers. You know, insofar as your work is saying ozone loss isn't just a human made problem. The sea is also partly to blame. Maybe. I think more scientists are very conservative bunch, as we should be. So I think that that is part of the academic process, if you like. Well, Lucy, I'm going to take a break from the science now because you were also busy developing another interest alongside your research, duathlons.

19:44I have small experience of duathlons, having done just one myself. I'm not quite at your level. But basically, it's a twist on the more familiar triathlons, but without swimming. So it's running, cycling, running. Is that right? That's right. Yeah, it's a triathlon for those that can't swim very well or don't have time to swim. Yes. And as you know, the final run is quite painful. It's like you've got broomsticks for legs. Oh, God. I remember the one and only time I did it, all the contestants had numbers alphabetically. So I was Al-Khalili, number one. Remember, you know, doing my cycling the middle bit and some child talking to her mum as I was cycling by somewhere and towards the back.

20:20Mummy, look, that man's number one and look how far behind he is. God. No, absolutely. No, never run with young people. No, absolutely. And you're right, getting off your bike and then having to do a bit more running. oh legs are like jelly but for you this wasn't just a hobby you started competing you went on to qualify for team gb taking part in the 2015 world championships in australia what was that experience like amazing really i mean i was quite a sporty kid but then like most people you have kids you've got no time for exercise in your 30s so for me it was hitting my 40s seeing that middle age was around the corner perhaps and then going back into it so i was a moderately good runner a moderately good cyclist my children had started cycling so I became a cycle coach and that sort of honed my track skills a little bit it's kind of the Venn diagram of where you know running and cycling meet and it's a fairly niche sport so if you're moderately good at both of them it turns out you can be quite good at the two things put together so I found myself on the podium at some events I thought wow this is actually quite quite good I'll I'll continue and then qualified for the age group team gb uh which was in australia and i had a sort of mad five days competing completely jet lagged and not really knowing which way was up um and i was just really glad to complete it the last thing you want is to go there and then you know fall over at the start or something like that but yeah it was a great experience and i'm glad i've done it but i'm quite happy now to uh throw away my my strava and you know relax back keeping your team gb i still have my team gb triathlon suit, yes.

21:54Excellent. Well, okay, so duathlons are an endurance sport. I'd argue scientific research can also be called an endurance sport at times, which is tougher. Yes, good question. I think science, because obviously, I'm not an actual professional athlete. So apologies to any of those out there that might be listening. But I do think with sport, bar injuries and everything else, the more you do, the better you get. And with science, is often not like that. You can have sometimes years of setbacks before something good happens. So there is a longer term resilience that has to happen, I think, in science, definitely.

22:32Well, Lucy, we mentioned the Montreal Protocol earlier. The global treaty first agreed in 1987 where countries committed to phase out chemicals like CFCs to protect and restore the ozone layer. Now, that protocol is regularly updated based on the latest scientific assessments. and you were first invited to be a reviewer back in 2010. By 2023, you were co-chairing the protocol's scientific assessment panel. Now, without getting too much into the nitty gritty, what's it like being part of that process? Initially, very scary, I would say. You know, our job as co-chairs and as a scientist is to assess the scientific information that's relevant to the protocol and present it the best we can.

23:14But there's all sorts of other things going on, The diplomacy, the politics, but it's fascinating, absolutely fascinating. So I am very much enjoying the journey. Well, just last year, you presented the panel's findings at the 37th meeting of the parties, as it's called, in Nairobi. What did you tell the assembled world representatives there? Well, first of all, the scientific assessments are made every four years. The latest one will be this year. So we're in that phase of the assessment. So I presented the major results that will come out of that, along with the issue that's probably the hottest issue right now for the Montreal Protocol, or one of the hottest issues, and this is emissions of a gas called HFC 23, which is fluoriform, which is a very potent greenhouse gas and has been increasing in the atmosphere for some time.

24:02Generally speaking, how responsive do you find different nations are to the scientific advice that you and colleagues are giving? I think they are responsive. It's a different matter as to what their national priorities are and how they interact with that science. So I mean, I'm a complete novice in all of this and learning. There are other people, seasoned goers to the Montreal meetings, who see the way the diplomats are talking and understand what it is that's behind the scenes. So there are national priorities that underlie these responses for sure, but some of them have an enormous appreciation and understanding of the science, which is great.

24:41Are you optimistic then that those in power will make changes for the better? HFC 23, which I just mentioned is a hot topic. We are yet to see action on that one. But we continue to be asked in the scientific assessment panel to bring information to them. and so you know I'm hopeful that in the end we will be able to give them precise enough information to make an action but all decisions are made by consensus so that's a tricky one. But what happens if the world doesn't act to bring down these HFC 23 levels? We will see adverse effects on climate it's already contributing about 15 % of the radiative impact of all HFCs.

25:20I mean there was a scientific study that showed the take up of HFCs, particularly by developing countries, because of the continuing air conditioning and refrigeration needs, was just going to go up exponentially. And, you know, we'd be facing... Because the world's getting warmer. The world's getting warmer and more populated and developing countries in some cases are getting richer as well. So, you know, off it went. So if we don't do it, we will continue to see a warming influence. And this has a global warming potential of around 14 ,000 times more than CO2. Great. Another thing to worry about.