Jim Al-Khalili

Hello! 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 Salvatente 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.

She 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. Thank 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. But 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?

Well, listeners might remember headlines in the 1980s around trying to restore the ozone layer because scientists found this hole above the Antarctic. So how is that going? I mean, the amazing thing is only two years after the ozone hole was discovered, the Montreal Protocol was signed.

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?

So that's what I ended up applying to do at university. 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.

The physical side, physical chemistry, the mathematical side. And you say things picked up after that accident. Certainly you ended up graduating with a 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. Now, as you mentioned, the troposphere being the lowest layer of the Earth's atmosphere. First of all, perhaps you can explain what halogens are.

Kyllä.

Ja myöhemmin, ei minun ryhmäni, mutta toiset ryhmät löysivät, että nämä pieniä partikkoja voivat kasvaa oikeissa tilanteissa ja ne voivat vaikuttaa tuuluihin. Ja sitten sinä todellakin olet ilmastonvaikutuksessa. No, vuonna 2000, Lucy, sinä johtasit Yliopistoon, johon sinä edelleen olet nyt. Ja niin me menemme Cape Verdeen. Miten idea tuli ensimmäisenä tehtäväksi tutkimustilanteeseen?

So you go over there to recce the site. Do you remember that first trip to Salvesente and what made it such a perfect spot for the station?

Well, the Cape Verde Observatory started collecting data from late 2006, and now it's a World Meteorological Organization watch site too. Did you ever imagine in those early days that this would become one of the world's rare long-term atmospheric research sites?

Vuonna 2008, Lucia, saavuttamalla näkökulmastasi Suomesta, julkaisit luonnollisen tutkimuksen, jossa näkyi, että halogenaalien kemikaatit olivat liittyviä suurta ozoonikäytäntöä tropiallisessa Atlantikassa. Kertoisitko minulle, mitä näitä tietoja osoittavat?

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.

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.

I 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 my word, oh god, yes.

I remember the one and only time I did it, all the contestants had numbers alphabetically. So I was Al-Khalili, number one. I remember doing my cycling, the middle bit, and some child talking to her mum as I was cycling by somewhere towards the back. Mummy, look, that man's number one, and look how far behind he is.

No, no, no, no, no, no, no.

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?