Amy Hi and welcome to this episode of the Science Focus Podcast. I'm Amy Barrett, Editorial Assistant at BBC Science Focus magazine. Started by Michael Faraday in 1825, and now broadcast on national television, the Christmas Lectures bring a science topic to our screens over three nights every year. The series of lectures has always been held within the Royal Institution in London, but this year, of course, is going to be slightly different. I'm joined today by three expert scientists Tara Shine, Chris Jackson and Helen Czerski, who are going to be presenting the 2020 Christmas Lectures, titled 'Planet Earth: A User's Guide'. In Lecture one, geologist Chris Jackson will reveal our Earth's climate story through the rocks and the fossil record. In lecture two, physicist and oceanographer Helen Czerski will talk about the part our oceans play in the climate crisis. And in lecture three, environmental scientist Tara Shine will talk about carbon emissions and what we're really breathing in. So let's go in that order, shall we?
Amy Chris, in lecture one, you tell us all about rocks and fossils and how they help us understand the Earth's climate and how it's changed, but you also talk to us about tectonics. It might seem like volcanoes would contribute to global warming.
Amy We can understand heat, warming, that sort of thing. But it's not quite the case that way, is it?
Chris Jackson No, so the main role that volcanoes play is by bringing carbon from deep within the Earth, and it's the carbon that that those volcanoes bring from deep within the Earth into the atmosphere that then creates carbon dioxide. So it's not necessarily the hot volcano. I think it sounds logical that volcanoes are hot and that the stuff that comes out of them is hot. But it's not the heat, it's the carbon. And so it's the carbon that then charges the atmosphere with carbon dioxide and causes the global warming. And then also there's an associated effect. So the increased carbon dioxide would enhance the greenhouse gas effect. But there's also a short term cooling after some major volcanic eruptions. So when you have a major volcanic eruption, one thing that comes out of a volcano in addition to lava is ash, and that's just fragmented rock particles. What they do is form this blanket, which can be very rapidly and efficiently mixed in the atmosphere around the whole planet, such that there's less and there's less heat coming onto the Earth. So it actually cools in the short term. So there's less radiative energy coming from the Sun into the Earth. And so you get at a short term cooling, but then a long term warming. So there's two effects of these large volcanic eruptions, not just one.
Amy We can see, through the fossil records, the impact of humans, but also the changing climate that the Earth has had over its entire history. But, how can you use this information to understand what steps we need to take in the future against climate change?
Chris Jackson So for me, the exciting thing is a lot of the discussion around climate change is rightly in the here and now in the future. So it's what's happening now, what can happen in the future. But the geological record actually has allowed us to establish a baseline. So, it can it can allow us to see how carbon dioxide levels and the Earth's temperature have changed over tens years to hundreds to even a few billions of years. So we can get that baseline and then that allows us to put into context what is happening now and what may happen in the future. Even more importantly than that, what we can also look at is the biodiversity through time. That is how life on Earth has changed in response to those changing temperatures, because that's ultimately what we, as selfish humans, are all about. So, if you go and have a look at the rock record, that allows you to piece that together and see times on Earth, which were very, very hot, how was the total biodiversity impacted by that? Because then it gives us a sense as to the pace of change of the climate and temperature in particular, but also the response of life on Earth to those changes.
Amy How far away are we from the baseline?
Chris Jackson So there have been times in the past where the carbon dioxide levels have been higher and there have been times in the past where the temperatures, the global average temperature has been higher. What is unprecedented is the rate of CO2 rise and the rate of temperature rise as a function of human activity. So that's the that's the really important bit of this, and that's why going back into geological record and looking at the rates of change in the past - when you start to see what's happening now - that makes it, in my mind, the kind of the hugely concerning thing that it is. It's because it is without parallel in the rock record.
Amy So we're leaving our own rock record right now. What do you think of our actions today are going to be leaving in 50, 100, a couple of hundred years time?
Chris Jackson Yes. So a lot of our activities on Earth are going to be recorded. The same way we can look at a core from 100 million years ago taken from beneath the seabed, and we'd see the layers of rock - we're going to see layers of sediment which recorded our time on Earth. One layer that we might see in there is a layer of plastic, for example, in the deep sea. So some of the plastic on land may not be preserved, but some of the things which are carried by winds and by currents and the deep sea may be recorded as a discrete or several discrete layers in the rock record. So, we will have an indelible kind of fingerprints in there. Radionuclides as well from nuclear weapons testing. There's going to be certain layers that are enriched in that material, which, again, are going to be not seen in the older rock record. You never know if we think that there may be another extinction driven as the function of the recent warming of the planet. Maybe there's going to be a layer in the rock in which there is clearly a contraction of the biodiversity on Earth.
Amy Hopefully, future geologists will see also the point of which we started to improve and change things and make a difference.
Chris Jackson Yeah, that you would like to think it would be a huge, you know we don't want to make it about achievements and we were great and we kind turn this thing around.
Chris Jackson But you'd like to think there is enough humanity and enough invention and innovation in humankind that we could take this challenge on. And we could eventually I mean, whether we're around to look at that layer of rock as a species anyway, is that is a different thing. But, it is an inspiring thing to think about that we could see there was a near disaster and then recovery, in the same way that we do for ancient extinctions or for certain species during extinctions.
Amy I want to go back to what you said about the energy that's stored in the ocean. I wonder if you could maybe explain that a bit further. So, in terms of energy itself, in what form does that take in the ocean?
Helen Czerski Most of the energy in the ocean is in the form of heat, but there is also kinetic energy. So, we know that it takes a lot of energy to boil the kettle and we don't necessarily see it because you just switch a thing on. That light comes on, and sometime later there's tea. But if you monitor the energy use in your house, the two biggest spikes are basically the kettle and the tumble dryer. Tara might correct me if I've missed anything out there, but but the kettle, you know, it's three kilowatts - that's an enormous amount of energy. What that means is that you don't have to heat up the ocean very much to store a lot of energy. And even though it doesn't heat up the ocean very much, once it goes to other places it can have quite large effects because that's a lot of energy. So, the ocean is basically a battery for Earth. It helps as it makes our planet a lot nicer because it means that, say it's cloudy for a few days, the temperature doesn't drop by 50 degrees, for example. It only goes down a little bit and we all complain about it. But actually, the oceans are keeping us warm and during the very hot summer days, they're actually keeping us cool. So, the ocean is that store of energy for the Earth. It's something that the Earth's system, that the machine of Earth, can store up when there's plenty of energy and then extract it back when there's not so much energy available. The ocean is the Earth's battery. You can imagine Earth borrowing energy from the universe: it comes in, the energy hangs around in the Earth's system a bit and eventually it flows away into space. And we're just holding on to a bit of it, using it - sort of getting in the way of its journey out on into the universe. But to do so, we need a store. We need a store of energy in order for that to happen, to deal with the kind of lumps and bumps of energy coming and going. So, the ocean is critical for all that and it also moves energy around the planet. You know, the Poles would be much, much colder in the depths of the Arctic winter if there wasn't an ocean. Actually, you can see that in the surface temperature in the Arctic, in the Antarctic during the polar night. So, yeah it's hard because we look at the ocean and we just see blue and it's sort of flattish and there's lots of it. But, actually there's loads of stuff happening underneath the surface as it shifts that energy around.
Amy And because of its nature, as a battery for energy on Earth, does it mean it's one of the best sources of renewable energy?
Helen Czerski No, interestingly. So, there are ways you can extract energy from ocean temperature. It only works in a small number of places. So here's the reason why. Basically we talk about energy and really, if you're being picky, when it comes to renewable energy, it's not energy we're short of - at all. What we're short of is useful energy. What you need in order to have useful energy is you need a difference. So, let's imagine you are a bird soaring in space if you're travelling in the atmosphere. If you're travelling at the same speed as the wind so you don't experience the wind because you're moving and the wind is moving but relative to each other, there's no movement. So there's no doubt that you've got kinetic energy and the wind has kinetic energy, but because there's no difference between those two positions, you can't you can't get anything useful out of that. So, from the point of view of renewable energy, the ocean is very low grade energy for humans. Not for the ocean because it runs the system. But it's very low grade because it's kind of a bit warm, there's not very big energy difference. So you can't extract energy from a small temperature difference. That's the reason that sunlight is useful, because bright sunlight, it makes a really big difference. You have a dark day and you have bright sunlight - it's a huge difference. So, you can definitely take usable energy out of that. There's a fundamental physics point here, which is that it's this useful energy that really matters. So although the ocean battery is really important, because what it carries is low grade energy, it's kind of not very different from its surroundings, it is quite hard to extract energy from it. There are a couple of exceptions. Heat pumps which use the difference at the tropics between the very warm water at the surface and the very cold water at depth. There's an energy plant in Hawaii that I visited where they basically do that - they kind of have a hot tub and a cold tub to the ocean. They have very entertainingly coloured them red and blue. But it was built as a demonstration plant, and even in Hawaii, they can only just get enough energy out of that to make it workable. The difference isn't big enough, but wind and waves and all those kinds of things, those there is a big difference. So actually being on land, we can use the energy that tends to come with stationary things like a wind turbine, you know, where the weather might be right. The warmth of the ocean might help drive weather and the weather pushes the wind turbine round. So, sadly, although it may be the case that we're accumulating heat energy on Earth, it's not very useful for running our society with.
Amy So we've heard about renewable energy from Helen a little bit. So,Tara I wonder if you can help us after this. Our listeners have now become viewers of the Christmas Lectures that they come out. If they're fired up to learn more and do more to help look after the planet, what can they go and do next?
Tara Shine They can do lots of things, I guess that's number one. So quite often in the face of a really big, overwhelming problem, we can feel just that - overwhelmed and feel like there's no point and think "what I do doesn't make a difference". I would challenge that a little bit, not because your small individual actions are necessarily going to save the planet (in fact, they won't) but because the actions of many people really do count. And because you have an influence - each of us has an influence, particularly on our peers, on our friends and on our family and on people in our community. They're going to really listen to you and respect what you say. So I think that if people are curious about the Earth that they live in, if they're curious about how things work. If they ask how and why, and they seek to get a better understanding of even the everyday objects in their house, or why are things disposable after one use or why why are some fuels so cheap in the world and others so expensive? What's behind all of that? If you ask questions and you play your part, even in the small things that you can do within your home. Even, as Helen says, even looking at your kettle. It is one of the most energy intensive appliances in the house. If you boil it three times before you make a cup of tea, or fill it to the top every time you want to make one cup of tea, that seems like a small thing but actually has quite a big impact on your electricity bill. It accounts for 85% of the carbon footprint of your cup of tea, just from boiling the kettle. So, even these small things, they are having a direct impact on your life and on your pocket, but it's more about the the collective sharing of those acts. So passing that hint on to somebody else so that they do it too, that's where your real power lies. So your power is really in how you share your actions, how you use your voice, how you use your leadership. Whether that is as captain of your sports team or in your school or on your debating society, whatever platform you have, that's what gives you power.
Amy And of course, there are big impacts coming from organisational changes when big companies or governments or anyone as a group does something. What sort of initiatives are out there currently you're seeing that give you hope for the future?
Tara Shine Yes, at the moment, although the COP26 has been postponed for a year - here in the United Kingdom will be the host of the 26th Conference of the Parties of the Climate Convention - it's still a really important point in time when that convention happens. It's when the countries come back five years, now six years, after the Paris Agreement to say, "this is what we've done and this is what we're going to do next". So they have to come back with bigger, bolder statements of intent around how they're going to take action on climate change. Even in this weird COVID year, there are more and more cities, companies, states and countries that are coming up with more ambitious climate commitments. They are putting their commitments to climate change in law, and are actually realising that they have to get to net zero emissions by the middle of the century. So, I find that really heartening. That's important for us to know too, as we try and make changes in our own lives, that the change is happening at the larger scale, too because that's what systemic change is. Systemic change is going to be a top-down, bottom-up effort, and keep an eye to that, too. Again, we can have a role in holding our own governments to account. We have a role in holding companies and big multinational corporations to account. So, being inquisitive about what they're doing and asking questions and using any power we have, whether it's our pockets or our voice on social media or with our friends, all of that is a way to contribute to that as well.
Helen Czerski Can I add something on the optimism actually? Which is, it's really easy to feel that things are changing really slowly. But the thing is, we're not starting from the beginning of the running track here. My mum, last week, sent me a picture of me standing next to her 25 years ago campaigning for Friends of the Earth on the streets of the town that I lived. What was interesting about the picture was, looking back, it was much easier to remember how it had been. These are not new problems and people have been thinking about them for a long time. I think that the reason that's important now is that people are really starting to talk about them a lot more, which is brilliant, but a lot of the ideas have been turning around for decades so they've now got to the stage where they're ready for use.
Helen Czerski It does feel frustrating sometimes, it feels like nothing's changing immediately. Actually, on the time scales of human civilisations, on the human lifetime, things are changing really quickly. The conversation is really important, but also all of this work has already happened to come up with good ideas. They already exist. And, there might be more of them and they might be better but we're also building on a foundation. We're not starting from square one. And I think that's really important when it comes to the the scale of the task is realising that actually were already quite a long way along this road.
Tara Shine Yeah, and I would say that that's a message that I give a lot to young people too. I know sometimes it can feel like we've just lumbered them with this big problem that we've caused and we've done nothing about it. But there are lots of boring older people like us, or maybe mildly interesting people like us if ask someone who isn't my child, that have laid a lot of the groundwork. Whether that's in the policies and the international conventions, or in figuring out how to make wind and solar energy at scale and at a cost that's less than coal and oil. A lot of this stuff is there, it really is the ramped up moment right now. And that ramp up moment is really exciting.
Amy Chris, do you have anything you wanted to add to that conversation about optimism?
Chris Jackson No, just to echo the idea about the solutions being there already.
Chris Jackson I think what's now happening is people leaning on governments to actually implement those right? So one thing is making a commitment or writing a policy, the other thing is actually putting some money into something that will actually manifestly have a positive impact. I think that's where we should feel empowered to go and vocalise our concerns to governments to make sure that they make good on the promise. So, yeah, we're not short of ideas. Maybe we're just short of will sometimes at the appropriate level.
Amy Thank you. I wanted to talk a bit more generally about the Christmas Lectures now we've got about 10 minutes left.
Amy I had the pleasure of watching one last year being recorded and I was surprised at the difference between how it's recorded and how it comes out, polished on the TV. I assumed the lecturer would kind of do everything as smoothly as they appear to on telly. But obviously, you know, things do end up going wrong. There's animals that don't quite do what they're supposed to, there's demonstrations that don't go to plan. I wonder maybe, Helen, you can answer this one, what's the bit that you're most terrified about going wrong on the night?
Helen Czerski Well, obviously, we will have a virtual audience and not a real audience. A lot of the filming will be very similar. In the sense that, normally if you're making a TV documentary, you'd stop and start and you do everything in bits, and this will be filmed pretty much as a lecture. Even though we'll be talking to cameras rather than to physical people who are there in the room. So, I'm not terrified of anything going wrong. But, I wouldn't tell you if there was a demonstration, to be honest, that I was really worried about going wrong, because it might not and that might spoil the surprise.
Helen Czerski But the thing that is hardest, I think, for us and will be hardest for us is that the fundamental unit of human civilisation is a human talking to another human. And it's a very powerful thing. People are interested in other people fundamentally, and we get a lot of cues from talking to other humans. So, in a live situation that's there. The wonderful thing about the Royal Institution as a place to talk normally, is that you are right in the middle of it. What you see on TV are these very steep seats that curl around and you as the lecturer, on whatever lecture you're giving, are right in the middle. It's like a Greek democracy, you're in the middle of all the people and you have to defend yourself to the surround sound audience. Obviously, when you speak to the audience, you are connecting with them. You hear them breathe, you can hear if they're not interested, actually, they go very quiet. Even if they think they're being quiet, you can feel the response in the room.
Helen Czerski So the thing that is hardest, I think, for us is that as a human, you're used to judging that in real time. Right, you can you can build and you can change this sentence based on what happened with that sentence. And, we won't be able to do that. So I think it'll be interesting managing the emotional journey of this thing, because if I talk to you and tell you a story, I'll hear you react to that story. And we won't have that in quite the same way, and the entire format is set up to get those reactions in a way that TV normally isn't. So, I guess my biggest concern is, even though I won't have any way of judging, it is sort of misjudging the way the audience is reacting at home. Although we will have a virtual audience, it'll be a little bit different. But, I have every confidence in the Royal Institution demonstrations team. It has to be said that the most impressive thing about all of this is the amount of effort that the Royal Institution and others put in behind the scenes to make these demonstrations work. We all have the luxury of, although we have the ideas and we help, we're not the ones who are adjusting the height of the glass tube 14 times in the afternoon to try and work out how to make it work. So we have to acknowledge the teamwork that goes on behind the scenes to really make these these things work. Because you still have to have a demo that works. Actually, one of the things that I'm excited about for my lecture is there are ocean demonstrations that we academics, we don't have time to build that. We don't have to spend an entire afternoon, adjusting tube 14 times to see what works. There will be demos that I think are useful from probably all of our lectures for teaching. Because you don't normally have the opportunity to set them up. Once you've done it and you filmed it, then they become useful to everyone forever. So that's a great thing.
Amy And of course, you can watch previous lectures online as well. I wonder have any of you got a favourite Christmas Lecture or lecturer that you've watched that you loved?
Helen Czerski I've got two that I remember, but one of them is probably Chris's. So the two that I remember growing up is Frank Close's 'The Cosmic Onion'. And I remember James Jackson's The Planet one. I can't remember what it's called, actually. Chris has probably watched it. What is it?
Chris Jackson I've never watched any of the Christmas Lectures. I've talked about this and we can talk about why. But I've never watched any of them - apart from sending me some of the tapes.
Amy Why? So I guess it depends on Christmas traditions, as to what you do.
Chris Jackson Yeah, I wasn't interested in science growing up and my parents were both nurses. So as a child, I was too busy playing with my football and climbing trees. And I think it's important to recognise that people within science nowadays or science for their job, they weren't always there - that, you don't have to be soaked in science to become a scientist. I'm not embarrassed about never having watched the Christmas Lectures before. I'm a little bit embarrassed. I got asked to do them having not watched them. Yeah, I think we just all come from different places and we all end up working on similar things.
Tara Shine Yeah, I live in Ireland where they we had two television stations growing up, but two Irish television stations. So, the BBC was something exotic that we got to see if I went to someone's house who happened to have parents who would pay extra money to have BBC. My dad certainly was not, so I didn't grow up with the Christmas Lectures either.
Amy Even the term 'lectures', my parents didn't go to university. So for them, lecture was something that was academic and they weren't going to understand, so we wouldn't sit down and watch it because it came with that kind of impression. What does it mean to you, Chris, to then be speaking on them, not having watched them and being aware that there might be a lot of people out there who you don't reach through this audience?
Chris Jackson Yes, it's a huge responsibility in many different ways. One is to make science relevant and exciting. I think in 2020, we've seen science doing that in a very positive way, and being criticised in another way. So, to make sure that in my case geoscience is represented as well as possible. I think science in general, but then also geoscience particularly. Then just for the people around you, the people who are your friends and family, to make them proud of you. And that's less of a science thing, right? That's just you want to do the best you possibly can.
Chris Jackson I think especially with this climate change focus for the Christmas Lectures this year. I feel that there's a considerable weight of importance on how we message that, and who we touch and how we do that. And it's not saying we're going to solve climate change in these lectures. It's still we are just one of the steps and one of the mechanisms by which, I think Tara and Helen have touched on this, we can further the conversation. And maybe, like Tara said, is spark that inquisitive bit in people to go and find out a bit more about something because they heard Chris, Tara, or Helen speak about it. Now, that's hugely exciting, hugely exciting.
Helen Czerski And there is actually a benefit here to the online world. So, although these will be broadcast on TV, like you said, all the other lectures are available online. And what that does is it removes a barrier.
Helen Czerski In the past, if you did not come to this quite posh Mayfair venue and if you weren't on the invitation list, then you didn't get to see this, you know? And so I think one of the things that all of us came in caring about a lot at the start is that the audience, and this will be represented in the virtual audience, is that they are not just the people who always get to come. It's other people who get to be part of the virtual audience, as much as we've been able to manage. And so I think there are hopefully some things that will come out of having virtual audiences and online things which might stay because they open the door to more people. I think that is really important. Yes, there's all this tradition and this is the way it's always been done. And that's all brilliant. But there's no harm in the tradition opening its doors and sharing it. If you've got a good thing, why not share it as widely as possible and why not use it to to share views that come from as many places as possible? So all of that matters quite a lot. And I think this year is a really good opportunity to really push forward on that.
Chris Jackson I think I think you're right, Helen. People seem to forget that traditions arise. Things that we now consider as traditional arose from some set of norms that developed over a given period of time. So let's make new traditions.
Amy And not be afraid to kind of let our own current traditions change or perhaps leave them behind for new ones.
Helen Czerski We can hold onto the good bits, right. If there are good things. So, this was a set up for children in 1825, which is quite a thing all by itself. The thought of having a science lecture just for children in 1825, that's a great idea. But then we have to hold on to all of it, we can do without the cholera and the top hats, and all of those things.
Tara Shine Yeah, I think a lot of a lot about finding solutions to things like climate change is about changing habits. So I think that's an interesting tie in to. So, it's like Helen said, we want to keep the best of the things that we do and then lose the bad ones. Whether that's an addiction to fossil fuels or addiction to too many male-only panels or not an adequate diversity within science thinking and science representation. We can lose some of those things. Then in bringing in the new things, we can bring new fresh ideas. And it is that diversity of ideas and diversity of perspectives that we need. That's why this year's is really interesting, because isn't one lecturer with one perspective. It's three lecturers with shared and different perspectives, looking at our planet Earth in in a holistic way. To me, that's the excitement. It's the linkages between the different Earth processes and systems, and how we as human beings interact within those. That's really exciting. And within that, there's room for human beings creating new habits. And those habits can be pretty powerful.
Chris Jackson I just wanted to say as well one thing about asking about how the lecture is going to work. and things going wrong in demonstrations. That's one of the things I think is really important. Science is messy. Things don't always work. Things fall over, things explode. Animals don't do what you want them to do, as you said. And I think it's very important to tell people that. Again, I think this year has shown us that uncertainty and communicating uncertainty, and being honest about the scientific processes is as important as the outcome or the ultimate headline item or the bit that goes into the policy. Right. So I think that's a really good thing with the Christmas lectures. You know, balls fall of machine and roll across the floor or something won't quite work. And I think that's really, really good. I think it's fun, but I think it's I think it's real.
Amy Mhmm, bringing science on a pedestal as well.
Amy Looking forward, if we can, to 2021, and I know you haven't done much of the filming of the lectures yet but, if you could give the 2021 Christmas lecturer or lecturers one bit of advice or one piece of information that you've picked up on, what would it be?
Tara Shine I would say think big. I think the team that you work with is capable of pulling off big ideas - they think big.
Helen Czerski Next year's lectures, hopefully there will be a live audience again. But I think some good things will have come out of doing it this way. And so it's really important that it doesn't just go back to exactly how it was before. There are probably things that can be done this way that couldn't have been done in the other way. And it's important to incorporate those. So I would say, don't look at us as the weird ones that did a thing that will never be done ever again. Something out of this will be good enough that it gets done every year in the future. It would be great if they looked to find that.
Chris Jackson Yeah, I guess related to Helen's point, this is a good chance to keep on this path of democratising science. Taking the science out of this lecture theatre for a privileged few and bringing it into people's homes. There's the representation aspect of who me, Helen and Tara are. That is all, for me, that who's talking about science is as important as the science that's been done in many ways. Because what that means is there's more engagement by the global population, who don't often just look like the type of people who until 1996 were giving the lecture.
Amy That was this year's Christmas lecturers. Tara Shine, Chris Jackson and Helen Czerski. Do check Radio Times for information about how to watch this year's lectures over the holiday period. If you've enjoyed this episode of the Science Focus podcast, please do leave a review wherever you're listening to us. And for more science news, Q&A and features, head to sciencefocus.com or pick up the latest issue of BBC Science Focus magazine.
Listen to more episodes of theScience Focus Podcast:
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