Ideas - How a natural catastrophe 8,000 years ago may have fueled Brexit

Episode Date: February 9, 2026

For the first two billion years, the Earth didn't have oxygen. That's just one of the many fascinating details Peter Frankopan reveals in his book, Earth Transformed: An Untold History. The Oxford professor of global history takes us on a multi-million year tour, illustrating the breathtaking ways climate has shaped the Earth and human civilization. How the collapse of a sediment shelf 8,000 years ago isolated what's now Britain from Europe, and its potential influence on the Brexit vote in 2016. Or how climate fluctuations correlate to periods of antisemitic violence. There's a lot to learn in this podcast. Have a listen.

This program is brought to you in part by Specsavers. Every day, your eyes go through a lot. Squinting at screens, driving into the bright sun, reading in dim light, even late-night drives. That's why regular eye exams are so important. At Specsavers, every standard eye exam includes an advanced OCT 3D eye scan, technology that helps independent optometrists detect eye and health conditions at their earliest stages. Take care of your eyes. Book your eye exam at Specsavers today from just $99, including an OCT scan.

Book at Spexsavers.cavers.cautors.com. I exams are provided by independent optometrists. Prices may vary by location. Visit specksavers.com to learn more. This is a CBC podcast. Before we start this episode of ideas, why don't you hit follow on the podcast app that you're using right now? Following us is the easiest way to find out about new episodes as they drop. Our aim is to feed your curiosity with compelling stories and thinkers and to help make sense of the world today. Ideas episodes are available every weekday, so you're always bound to find something that piques your interest. If you already follow us, thank you so much. Maybe you could give ideas a rating or a review. Every little bit helps people find our podcast, and we really do appreciate it. Thank you for listening.

Now, on to today's show. Welcome to Ideas. I'm Nala Ayyad. And strap yourself in for our first. a time-traveling juggernaut. My name is Peter Frankapan. I'm Professor of Global History at the University of Oxford. Peter Frankapan's book is called The Earth Transformed, an Untold History. At last count, it's won 15 national book honors in the UK alone.

It traces the Earth's climate history back hundreds of millions of years and shows the impact climate has. had on virtually every aspect of human evolution and history, as well as the impact we humans are having on the climate itself. Your book is huge. It's massive in scope, and it draws on climatology, paleontology, psychology, botany, government reports, novels, news articles, need I go on. It's also huge physically. It's nearly 700 pages and weighs almost as much as a small dog. So let me have ask you this straight up. How are you still standing? Well, you know, 700 pages isn't, isn't that much. I've been telling people here that it's one pound for every 325 million years, which is,

which is reasonable value. I mean, it's true. Here in the UK, it's printed on sort of extra fine, thick paper. So it's more of a brick here. You guys in North America, a bit more frugal, so they're more used to making it a bit more compressed. So, No, I understand the reason for bookholders. But I don't mind a book that feels chunky and weighty, and I'd rather have a long book about something that's going to cover a lot than a long book about something that covers how people sneezed in the Victorian era. Yes.

Earth transformed does cover a lot, including one spectacular geophysical event you've maybe heard of. The single most famous moment of large-scale transformation was caused by an asteroid strike that impacted the Earth. 66 million years ago on the Yucatan Peninsula, and led to the demise of the dinosaurs. Such events were spectacular and devastating. They also played a part in the extraordinary series of flukes, coincidences, long shots, and serendipities that ultimately brought about the rise of humankind.

All life on Earth today descends from animals, plants and organisms that survived not one, but multiple mass extinction events. That asteroid strike that you mentioned 66 million years ago in the Yucatan, if we were actually able to view it, what would we have seen? Well, your retinas, I'd have thought, would have been burnt off you pretty quickly

if you were able to see it. And if they hadn't been, then it would have been the massive tsunami that would have got you or the rubble that came out. But the impact produced thermal radiation and a plume that sent up, obviously, giant tsunamis

and landslides that absolutely, scarred the ocean floor. There was emissions of 300 gigatons of sulfur and 420 gigatons of carbon dioxide. And all of that would have been hot. There would have been firestorms over the longer term, all the dust and the debris that was injected in the atmosphere blocked the sun's rays. And what that then does is provoke cooling because obviously the sun's rays can't get through and can't warm the earth. But also the photosynthetic cycles change because you need sunlight and water to create photosynthesis. So there's a huge, huge impact.

But in terms of just what we know, is there anything comparable? Like, is it similar to a nuclear bomb? Is it worse? Is it 10 times that? What's the scale? Well, so there's a global drop in average air temperatures globally of around about 10 to 16 degrees centigrade. I mean, to put it into some kind of context,

over the last 50 years, so since 1971, a new IPCC report, and you asked about nuclear weapons, a new IPCC report estimated that at the top end of the scale that perhaps 400 zeta joules, which is a lot of jewels of energy, have been absorbed by the oceans, because although it's not just the Earth that's warming, it's the seas too, and that ocean energy input over the last 50 years is roughly the equivalent to 25 billion Hiroshima bombs. and I suppose that's quite... Sorry, let me just get that straight. 25 million? Billion.

Hiroshima bombs. And there are a bit of variables on that. But that amount of change over such a period of time, it's not hard to explain to people that that's a dramatic set of changes. Just in 2022, before some of the heating events that we've been seeing in other parts of the world, 10 zeta jules, roughly was absorbed by the oceans. That's the equivalent of enough energy to boil seven, million kettles every second for every minute, day, week, month of the year. And that's to do

with, partly to do with how we burn things, partly how we live, partly do with energy sources, partly to do with natural things. Forest fires are natural events too. You know, they're not just to do with climate change, but it's the pace of these changes over the last 30, 40, 50 years that's so dramatic. And David Wallace-Wells at the New York Times puts it very well. He says that since the first episode of Seinfeld was broadcast. Humans have burned 50% of the carbon in human history. And being British, I don't really know what Seinfeld means. But roughly from the early 90s, or the Berlin Wall coming down, more or less, has seen a real acceleration in some of those processes.

And, you know, all actions from physics onwards, all actions have consequences. Forces produce counter forces. So, you know, the bigger impactor than the one that took out the dinosaurs was the size of Mars, hit the Earth and help create the moon. Formed from debris thrown into space at the time of the impact that created the Earth, the Moon has a gravitational pull that plays a major role in ocean tides. It is responsible for the flows that help transport heat away from the equator and towards the poles, fundamentally shaping Earth's climate. As the Moon used to be much closer to the Earth, perhaps half the distance away that it is today,

these forces were considerably stronger and therefore had a greater impact on the Earth's climate and also perhaps on its wildlife. Recent modelling suggests that big tidal ranges may have been responsible for forcing bony fish into shallow pools on land, thereby prompting the evolution of weight-bearing limbs and air-breathing organs.

The Moon played a role not only in the transformation of the Earth, in other words, but also in the development of life on this planet. It still exerts an important influence. Indeed, there seem to be important links between human behaviour, activity, and even fertility and lunar rhythms. Long-term data from women's menstrual cycles shows a correlation with lunar light and lunar gravity, with some scholars arguing that human reproductive behaviour was originally synchronous with the moon, but has been modified more recently by modern lifestyles. While the role of the moon in influencing and disturbing human behaviour is often reflected in popular culture and even in language,

the word lunatic suggests of a relationship between mental illness and the moon, any causal links are usually downplayed by scientists. However, some researchers have emphasized that manic episodes in patients with bipolar disorders have a remarkable synchrony with three distinct lunar phases. The moon, in other words, plays an important role in ocean currents, global temperatures and climate, as well as in reproductive cycles and life on Earth in general. Your book is such a sweeping look at history. It's divided into 24 time periods.

It has a cinematic quality to it. It's very visual. I could see it getting animated like Jurassic Park or BBC's Walking with Dinosaurs. Can you? Well, I'm a huge fan of different forms of media. I've learned that there's a real... It's hard to do well.

But the thing that I... When I read a book called The Silk Rodes that came out in 2015, and I got invited here in the UK, we do lots of literary festivals. And I guess it's a bit like Kevin Costner, you know, if you build it, they'll come. You know, so you walk out into these big audiences and it's very, very flattering because academics, we tend to talk to each other. We tend to be very ungenerous about each other's work.

We tend to jump quite quickly down each other's throats. And suddenly you're in a tent with, you know, sometimes hundreds, sometimes even thousands of people. And one of the big talks I gave soon after it came out, I said, as, you know, as I finished my talk, I'd like the first question to be asked by anybody under the agent. I think I said 18 and there was sort of silence. I went, is there anybody under the age of 18? No hands went up. Then a bit like sort of like a like a like a like a like a calling bingo numbers. I eventually got up to 25 and eventually one person put the hand up and I said, do you have any questions?

And they said no. And you know, that's a product and lots of things. You know, you might think if you're under 25, you've got other things to do on a Saturday afternoon. Sure. Then go to a literary festival. But I then had a meeting with my publisher where I told them this story and I said to you know, one day I'd love to write a a kid's version of Silk Roads and they didn't look like I was mad

but they then rang me back a week later and said do you mean that? So I said yeah it's so important to start kids in the classroom reading and I said you know my experience of writing Silk Roads and it's the same actually with the Earth Transformed is that almost within 24 hours teachers were popping up on Twitter saying

I've got this great idea for a course lesson where I'm going to teach my you know 12 year olds in the class about Little Ice Age or I'm going to teach about the importance of climate in Rome and then teachers communicating with each other about it. So exciting. So, you know, it's been it's been a pleasure to connect into different media and even coming on your show to talk about it on the radio. You know, it's a way of communicating ideas that it's so important for academics to get out into the so-called real

world and connect with regular people to explain why what we do, often funded by the taxpayer, why that's important. So let me take you down that road a bit further. Your book is titled, of course, the Earth Transformed and it has a subtitle that says an untold story. You know, one central element of your book is already well known, at least as a topic, you know, changes in the Earth's climate. So what is exactly the untold part? I mean, it's such a lovely question. You know, that definitely sets off a few colleagues, you know, I suppose what's untold is that, you know, generally history books, if you remember them from school like I do, generally don't start with the beginning of the earth and the creation of tectonic plates, mountain ranges and how that affects our political systems today, for example.

True. But I think that the untold bid is about, I mean, you say that we're all aware of it. I mean, I don't necessarily think that we really are. I don't think people know that when the first Spaniards came to Florida. They spent 100 years complaining about how cold it was and wanted to go back home saying that we can't grow anything. It's a waste of money. And no point of settling it. And now Florida is a place where you grow citrus fruit.

Donald Trump goes to top up his suntan and possibly to face criminal investigations. But, you know, at that time, things were very different. I think people, you know, don't know that the borders of Canada were partly set by beaver populations and the demand for beavers, particularly in Europe, both for their furs and their pelts that were used for hats, but also for, I'm afraid, say, anybody listening, put your fingers in your ears, for their anal glands that was an important medical ingredient. So, you know, I think we don't really think too much about the fact that the world changed. When we think about the Roman Emperor, we think about Russell Crowing Gladiator and, you know, emperors fighting with you,

or knifing each other in the bathtubs. We don't really think about where did these great bathhouses that we've all read about. How do they get heated? Every single piece of glass, every single piece of metal made in Rome in the Roman Empire, you needed a heat source, as at all protein, most food. Where do that come from? What if you cut down all your trees? Was Rome ecologically and environmentally sensitive?

Were people in Rome, for example, worried about wood sources? Same thing in Mesopotamia, 4,000 years ago or in China, the same period. If you run out, if you over-exploit your ecosystems, what goes wrong. There's a fantastic, beautiful city in Central Asia called Pangecant that's quite famous for its frescoes on walls that are showing Sogdian banquets and lots of people from all over Central Asia gathering together and meeting and talking and sharing. And, you know, that city became really just a victim of its own success. It became too big to cope with its environmental envelope coupled with human decisions, coupled with people being drawn in for nefarious

reasons, wanting to knock over places that are rich and powerful. So there are all sorts of ingredients that go into it, but I think we don't really think about natural histories in the past. For around half the Earth's existence, there was little or no oxygen in the atmosphere. Our planet was formed through a long period of accretion, followed by a major collision with a Mars-sized impactor, which released enough energy to melt the Earth's mantle and create the earliest atmosphere from the resultant exchange between a magma ocean and vapor that was anoxic, that is to say, lacking in oxygen. The Earth's biogeochemical cycles eventually resulted in a radical transformation.

Around 3 billion years ago, if not earlier, enough oxygen was being produced to create oases in protected nutrient-rich shallow marine habitats. Whether because of chemical reaction, evolutionary development, sudden superabundance of cyanobacteria, volcanic eruptions, or a slowdown in the Earth's rotation, or a combination of all five, atmospheric oxygen levels accumulated rapidly around 2.5 to 2.3 billion years ago, resulting in an episode known as the Great Oxidation Event. This was a key moment that paved the way for the emergence of complex life as we know it. I was fascinated to learn that for half of the Earth's existence of about 4.5 billion years,

there was no oxygen, as in no oxygen. So what did the Earth look like without oxygen then? It's a good point made by many geographers today saying it shouldn't be called the Earth. That's for one thing. It should be called the ocean because even today, 70% of our planet is water, where the continents have been distributed. So the tectonic plates of the Earth form and then start to create the continents that we recognize today. So dramatic are those changes that at the top of the Himalayas, on the roof of the world, you find a marine fossil. because not so very long ago

the Himalayas were on the sea floor and the pressure of tectonic plates pushing the Indian subcontinent into the many plates of Asia actually creates this enormous pressure that has driven these mountains upwards. It's extraordinary. I think really the challenges when we think about history

and if you were to talk to any of your friends at dinner and to talk about what's your favorite period in history, you know, you might get someone who takes a shot on saying, you know, ancient Egypt. But in the grand scheme, you know, three or four thousand years ago is nought. 0.0, naught, naught, naught, 0, 01% of the world's history, right? And to imagine the ancient Egyptian world, you think it's just impossible to understand these guys didn't have laptops.

They didn't have cars. They used papyri to write things. You know, they had to make ink by grinding things up. You know, we think of the Victorian age as being, you know, so amazing. People having electricity for the first time. and running infrastructure with allowed running water and being piped around the cities

we think of that pace of change as being almost impossible to understand and that means that anything before about the year 5,000 BC is kind of, that's just a very distant past where we can't really conceptualise so things that happened 100,000 years ago or 300,000 years ago, basically the same thing

and that challenges I think our perceptions of time because again, anybody listening if you said, you know, what do you remember about the late 1980s It's like, wow, God, that feels like a long time ago. And I can promise you, in historian's terms, it really wasn't. Well before humans ever appeared on Earth, there were massive swings in average temperatures, you know, levels of carbon in the atmosphere and also of sea levels.

Can you cherry pick from across the eons to give us a snapshot or two of the incredible range of pre-anthropogenic climate change? Well, one that is that the ice age, which started, the world started to sort of warm about, about give or take, 12, 13,000 years ago. At that point, the continent of Australia was 30% bigger than it is today. And there were lots of ideas that we had about that. Now we, now new advanced sciences and things like LIDAR, which is a sort of scanning devices where you can, you can effectively X-ray land and you can see what lies where. And you can use that across the forest canopy, for example, in Guatemala, Mexico to find structures that you can't see with a naked eye.

Some of these things, in the case of Australia, you can find habitations that are 150 miles offshore now. And I think that the thing that's interesting about that to me is not just that, well, wow, wasn't Australia bigger? Can you imagine if it was that size now? It's what must that process have felt like spread over a couple of thousand years, where the sea came up or a few says. to meters every year, you know, that in the course of a lifetime like yours and mine, you know, you'd say, well, I can remember that the seat didn't quite used to be that high, or it hadn't come in that far, but it obviously is moving. And I suppose that why that's particularly resonant with me and the things that I think we're all thinking about today is we read a lot

about the current changes. And the big difference, the two big differences today are never in the past as all the world's temperatures moved upwards at the same or downwards at the same or downwards at the same time, not obviously, or certainly not in human history, and at the moment, 98% of the world is warming. So, you know, we can predict that these things are extremely likely to happen unless there are interventions of one kind or another that stop them. Those could be, you know, nuclear war, massive volcanic eruptions, there are all sorts of ways in which those variables might change. But I think we all are confronting and all of us realize that the world is rapidly changing in front of our eyes, largely because of human activities, but not, only because of human activity. So today, for example, we have the highest carbon dioxide concentrations in the atmosphere

than we've had for two million years. And we're the warmest in the world at the moment that we've been for 125,000 years. And every now and again, I come across someone standing at the bus stop or, you know, hassling me on Twitter who says, well, you see, the world has changed in the past and humans will adapt. And in a way, what my book also tries to show is that that's absolutely the opposite of what happens, that if you don't adapt, then your city, your society, can collapse inward. So the lessons of the past is if you don't adapt to changing circumstances of all kinds,

then there are consequences. So the other thing that often comes up in conversations about climate change, not being caused by humans or about it being a cyclical process, it gets politicized very quickly. How have you avoided that trap when someone says, well, climate has always been changing? I've learned a lot of things in my career. One is to try to not have arguments with people who don't want their opinions to be changed. Some you can't win. I mean, as it happens right now in the United States, about 50% of Republican congressmen don't believe that the world is warming or that it's to do with anthropogenic causes.

And in fact, even higher percentage of Republican senators. Now, I don't think that I can give any kind of particular confidence to people who think that, well, we'll just solve our way out of this one. And in fact, the situation looks to me pretty precarious, and it would seem to me that we should be thinking quite hard about that rather than sticking ahead in the sand. Because if the climate deniers are wrong, then, I mean, if they're right, I beg you by the, there's no major consequences.

If they're wrong and 99.5% of the science is right, then the costs are, and the consequences are profound. When seen through the telephoto lens of Peter Francapan's view of history, the all-too-familiar phenomenon of climate denialism, comes into sharper focus as an extremely recent development. Some of the very, very, very earliest texts talk about environmental dangers and precariousness. I mean, if you think, let's say the book of Genesis,

so the first book of the Bible, but is also, of course, from the Torah and in the Quran too, the book of Genesis about Adam and Eve, humans are the last edition into a world that's been perfectly formed by the creator where everything is in perfect harmony, and then humans are put in this harmonious, world until you've got one job, which is don't eat from that tree, right? If you don't eat from

that tree, you'll have everything you need, you know, free Wi-Fi, you know, all the rest of it. Free food, you don't have to work. Everything tastes glorious. And when Adam and Eve are said to transgressed, they are evicted from the Garden of Eden and the punishment is an environmental and ecological one, which is the land is going to be hard. They're going to be thorns and thistles. You can't necessarily grow things. There will be flood. There'll be droughts. And I think that that speaks in one way to the anxieties of early humans, the first humans are writing things down. And this is reflected, of course, and mirrored in Mesopotamian accounts and chronicles written 4,000 years or 5,000 years ago or more, and in Chinese texts too, very early ones,

that are really concerned about change, are really concerned about not having enough food, are really concerned about not being enough rain, or about what happens if there are chronic floods. And I think that anxiety is something that you can trace back more or less as far as the first written records go in any text, any language, any region. The dangers of environmental degradation, overconsumption of resources, and unsustainable population load were not lost on people living thousands of years ago. The epic of Atrohasis, an old Babylonian text of which the earliest clay tablets date to around 1700 BC, reveals an acute awareness of the vulnerabilities that came from pushing ecological boundaries beyond their limits.

The gods had created humans, says the narrator of the text, because they realized that they had too much work to do themselves. Mortal man was created, therefore, with a specific instruction that he should bear the load of the gods. The trouble was that the gods had not accounted for the length of a natural lifespan, which soon resulted in overpopulation. It was not long before the number of people became too numerous, and the country was as noisy as a bellowing bull. This happened on several occasions, leading to the gods taking matters into their own hands, and decided to kill off most of the population in order to achieve some peace and quiet. This is Ideas. I'm Nala Ayyad. I spoke with Peter Frank Copan in June 23 about his book,

The Earth Transformed, which has even more relevance now. It encompasses, the sweep of our planet's climate history over billions of years. It portrays in devastating, almost cinematic detail the impact we humans are having on our planet's climate. And it does something else. It counters not only climate denialism, it also counters climate despondency. This program is brought to you in part by Specksavers.

Every day, your eyes go through a lot, squinting at screens, driving into the bright sun, reading in dim light, even late-night drives. That's why regular eye exams are so important. At Specsavers, every standard eye exam includes an advanced OCT 3D eye scan, technology that helps independent optometrists detect eye and health conditions at their earliest stages. Take care of your eyes. Book your eye exam at Specsavers today from just $99, including an OCT scan.

Book at Spexsavers.cavers.cair.cairits are provided by independent optometrists. Prices may vary by location. Visit Spexsvers.cavers.cai to learn more. Behind every Olympic moment is a human story. At Homewood Health, we're now proud to stand behind Team Canada and every Canadian, as we have for over 140 years. This moment is bigger than sport. It's about affirming that mental health matters in every arena. Visit homewoodhealth.com today. It is certainly true that there is plenty of good news, much to celebrate, and reasons to be optimistic.

This does not need to come at a cost. For example, a national air quality plan introduced in China in 2013 and the announcement of a war against pollution the following summer helped spark a decline in particular pollution in China of almost 40% in the years up to 2020. Beijing's air pollution alone fell by 55%, adding around four and a half years to the average inhabitants' life expectancy as a result. Peter Frankapan directs the Center for Byzantine Research at Oxford University, where he specializes in the histories of Russia, the Middle East, the Mediterranean, Persia, Iran, Central Asia, and China. So he's obviously more than qualified to have the unique position he holds there,

professor of global history. How does one become a professor of global history? You need to have a combination of great luck. You need to be in the right place at the right time. You need to be able to crawl through the shady corridors at night without assassins jumping out from behind the column. That's a skill in its own right. I know how lucky I am. Let's put it that way.

Peter Frankapan's book is entitled The Earth Transformed. And part of that transformation has been the impact that we, the 8.2 billion humans alive today, have been having on our planet. But he also portrays the cataclysmic changes that occurred eons before humans ever existed. There were still natural catastrophes that had little to no human agency involved. You described one that occurred around 6150 BC when a shelf of sediment 190 kilometers long in what is now Norway became dislodged. If we had had drone video footage of that event, what would it have looked like? Well, it would have been like the Fukushima tsunami, but much, much, much worse. You know, we all remember the horrific scenes.

I mean, genuinely chilling of that wave that to the naked eye doesn't look that bad, you know. But the scale of this one was huge. In around 6,150 BC, a 190 kilometre shelf of sediment off the coast of Norway was dislodged, creating a giant tsunami that swept south through the North Sea. The scale of the wave and the devastation it inflicted can be shown by models which estimate that it would have reached 21 kilometres in land, twice as far as the Fukushima tsunami of 2011. At the time, the wave would have killed everything and everyone in its path.

It swamped and submerged an area known as Doggerland that connected Britain with the European continent. British Isles at that point were connected to Europe throughout this area of land called Doggerland, and that then became submerged as a area. a result. And that single ecological event, that had nothing to do with humans, obviously wiped out all the communities

living on and near the coast. Again, the timing of this event was hugely important, partly because this happened at a time of the year when fishing communities, particularly in Scandinavia, would have been living there. But that served to cut off Britain from the continent. And that, in some ways,

has been maybe not the story of the last thousand years, but it's been a very important one in European politics. For lots of reasons, first, in the way that the British see themselves as distinct to Europeans. Second, because there's a small little gap, it's only 22 miles or so to get from Dover to Calais, but multilingualism in Britain is something different to how it works, let's say, in Europe, where borders have moved a lot to.

Also, the way in which, because we don't have land borders in the United Kingdom, apart from with each other, with our friends of the Scots and the Welsh and in Ireland, that meant that the way in which the British government, or first England and then Britain developed its armed forces, meant that it invested in naval power. And that naval power turned out to be hugely significant when it came to the age of empire, where we were not necessarily in such a good place to fight our European neighbours, but we didn't have to. So the size of the British Army, for example, was around about 60,000 at a time when the Austrians, the French, and others would have to put two or sometimes 300,000 men under arms. And that's a lot of textiles to clothe them.

That's a lot of food to feed them that the government pays for, the king pays for. There's a lot of extra rifles. That's a lot more dead when people go wrong in battles. So the British, for example, partly because of that event, had just a different ecological, geological, linguistic, political, and economic history. And there's a slightly cheeky line, and it is a cheeky line. Britain's separation from continental Europe was crucial in everything, ranging from the development and dominance of British sea power,

to the military outcome of the Second World War, to the exceptionalism that helped drive the Brexit vote to leave the European Union in 2016. It didn't cause Brexit, but, you know, there is definitely a drive, by which we feel in Britain that we are different to the continent of Europe, that we have a different history. And I don't think that that's because of tsunamis and geologies, but you know, you can't walk completely away from that. So we've been talking about the non-human impact on the earth and climate,

but let's turn to the effect of human presence. So when cities originated in Mesopotamia in southern Iraq, about 5,000 years ago, the civilizations that built them saw them as triumphs of ingenuity. but they were still incredible drains on the surrounding environment. Can you give us a sense of just how draining? Well, people who live in cities consume a lot. I mean, you have tradesmen and workers and so on.

But the first thing with a high population density or concentrated population, whether it's villages, towns or bigger, is you need to be able to have water sources. You need calorie availability. And quite often what happens is, I mean, as it happens, the kind of the major areas that become cradles of civilization. Mesopotamia's one. The Nile is another obvious one, the Yellow River and the

Yanksy River in China and the Indus Valley, others. In the case of all but one of those, they're in prescribed zones. It means you've got fertile lands and lots of water, but to either side of that fantastic strip, you've got mountains or, in the case the Nile, the desert. And that means that as your population starts to rise, there comes pressures on your natural

resources. That's one thing. But I suppose almost more important is that that also creates demand for the single most important thing, which is manpower. And manpower, whether it's coerced, whether it's paid for, whether it's enslaved, is crucial when it comes to building big monuments. It's crucial to ideas about hierarchies, about kingship, about economic elites who take the best land and want to keep hold of it and pass it to their next generations. And so there's a competition that starts to evolve when there's demographic pressure. And the one place that doesn't happen seems to be in the Indus Valley where houses around the same size, you don't find levels of inequality obviously on the ground in quite the same way, possibly even slightly different ways of understanding nature and understanding cosmologies. But Indus Valley scripts are still undeciphered. One very clever explanation, convincing explanation for that, is to do with the fact that the rivers that come down from the Himalayas carry a lot of siltz with them and therefore their courses change often. And because their course has changed often, it means you don't get to live next to the River Thames and you know where it's going to flow every year.

So try to make an investment in real estate and to the best plots. It's slightly different in the Indus Valley or seemingly to how things work in these other locations. And then you find the things that archaeologists and historians love, which is big monuments being built, big city walls, temples, palace complex. There are shows of force and of status, but also they require the memorabilms. of human labor to build them in the first place. Well, I want to go on in this vein for a minute because cities in the developed world now are where most of humanity actually live, and increasingly so in the developed world. So how different are the stresses that contemporary cities impose on the environment?

How different are they from what happened with ancient ones? Well, again, it's the speed. So at the moment, we're on average adding three million new city dwellers per week around the world globally. The urbanisation in China in the last 30 years is the fastest in human history by far. Some estimates suggest that between 2011 and 2013, China used more concrete than the United States did in the entire of the 20th century. Now, cities are not only bad places where producers of emissions and consumers of energy. And there's been a lot of activity around city planners and people working on sustainable cities over the last couple of decades.

that has been really quite productive. So the United States, for example, today has about 30% lower emissions than it did in 2005. So, you know, there are some real triumphs, but, you know, you can't just, I think, absorb populations in vast numbers indefinitely. And you mentioned the developed world. I mean, you know, in the United States, there is nine, maybe ten cities with a population of more than a million people. In China, there are 156 cities with more than a million people. Extraordinary. So when you look, when you look at air quality,

in many parts of Central Asia where I go to Bishkek, for example, and it's absolutely awful, trapped in valleys. The air quality in Delhi is as bad as smoking two packets of cigarettes every day. The quality of air in the UK, 90% of it's below World Health Organization standards. In Southeast Asia, places like Philippines, Indonesia, Thailand, Malaysia, nudging almost a billion people, you know, 700 million plus, they have an average life expectancy for every single man, woman and child, one and a half years lower than it would be

if the air quality met WHO World Health Organization standards. The other correlation that's intriguing that you draw is between changes in the climate and the prevalence of conflict, from spikes in anti-Semitism to all-out war. What example of that correlation surprised you the most while you're writing your book? Oh, well, the correlation of anti-Semitism and climate

is extraordinary. I mean, it's the idea that, that when climate changes, you know, when there's suddenly inflationary pressures, as a result, a lot of things, a war in Ukraine, wheat prices, energy prices, spiking, global markets, then there are consequences. And one is shortages, inflation. And inflation is not always to do with shortage. It's to do with anxiety and fear, people buying things that they don't even necessarily need for the time being, but to stock up. And, but there's data drawn from the persecution of Jews in Europe across a thousand cities over the course of about seven or eight,

centuries, which is a sort of pretty good data set, shows that a decrease in the average growing temperature season of about a third of a degree Celsius, which is not an enormous amount, is correlated with the rise of probability of Jews being attacked in the subsequent five-year period. And in fact, there's a higher proportion of Jews that get attacked in areas with boressoil and places with weaker institutions, so where there's, you know, a single autocratic king rather than diets or parliaments or groups of nobles who hold powers. So those kinds of things I think they make one think about what have we got that lies ahead of us. You know, who gets blamed for problems or who are the minorities that can get picked on?

There's a section in your book about weaponization of climate to use the weather to actually fight the enemy. So I'm thinking of the Vietnam War where the U.S. military ceded clouds to disrupt North Vietnamese troop movements. How did they try to do that? I guess you could take it slightly further back in time, which is, I guess, one of the functions of of different religions is to change the climate by making interventions to the divine,

whether it's God or multiple gods. You know, my favourite in Mesopotamia, the goddess who had beer left outside a tempine that would be quite a good as a deity, as long as it's cold on a hot summer's day. So I suppose the human efforts

to try to influence the climate through rain dances, for example, in many Chinese cultures, in West Africa and other parts of the world where I write about two about attempts to show that there are,

some people, shamans or priests or whoever, to bring the reins. And the difference, I guess, is to do that through scientific methods rather than perhaps more random attempts to try to convince beneficence. But I guess one of the interesting things is that the US Army started experiments on this in the 1830s and 1840s of trying to fire explosives up into the sky. And that didn't work particularly well. By the 19th century, attempts to intervene in the weather had become rather more determined in their methods and aims. Interest was particularly strong in the United States, where several pioneers set about trying to conduct experiments to see if rains could be induced.

One was James Espy, the first federally funded meteorologist who conducted a series of experiments in the 1840s to generate artificial precipitation by setting fire to large tracts of forest in the hope that a giant column of heated air would create clouds and would thus generate rain. Although these experiments ended in failure, other scientists developed new ideas based on the supposed correlation between battles that involved heavy use of artillery shells and the rainstorms that often seem to follow soon afterwards. Despite the lack of results, the US government took a keen interest, with Congress allocating funds to the Agriculture Department in the second half of the 19th century

for experiments to shock rain from the sky using a huge. explosives. The follow-up proved less successful, with no rain being produced over the course of two months of incessant destinations in what observers described as full-scale limitations of a major battle. This was hardly a surprise, according to well-placed commentators. The premise was flawed, a waste of taxpayer dollars, and the silliest performance that human ingenuity could devise. With that, the funding that had not yet been spent was returned to the Treasury. By the beginning of the 20th century, there was an idea that iodine seeding and cloud seeding of firing up iodine particles into the clouds would find a way of forcing moisture to gather

around the iodine particles and to fall as rain. And that sort of peaked, I guess, during the Vietnam War, where two things happened in terms of influencing and engaging in nature. One is one called Operation Ranch Hand, which was the use of herbicide to deliberately destroy forests and destroy fields to drive out the Viet Cong and the American US enemy which

galvanized something the charge of ecocide which we've again seen with the mining of a dam, the Khorfka Dam in Ukraine, deliberate destruction of environment. But the other one was to use cloud seeding and to use the ability to make rainfall. The Americans, what were trying to do is to make

the supply chains for Ho Chi Minh's army so muddy that vehicles wouldn't be able to deliver food, ammunition, hardware to Vietnamese positions. And then there was, of course, the scandal about this because it was denied by the American military

for some time until it turned out that in fact was happening. So there have been lots of efforts to do that during the 60s. There were many countries that have had climate change, enhancements and attempts to reshape to modify the climate since then. Some of those, for example,

have been used to keep the skies clear over Beijing when China held the Olympics. some have been used to clear the skies over Moscow when Paul McCartney was giving a concert where the transition went from rain to clearing the skies so much so that all of Paul McCartney's roadies had to wear sunglasses because the sun was burning so brightly so these things can be used for cosmetic purposes but I mean I think that we should all be not surprised to know that these are also going to be a part of our common futures where the ability to try to control particularly rainfall it's very advanced.

in China. One would expect in a few other countries too, but that will sit alongside, I think, other less sort of science fiction type ways to control the environment. So, for example, in the Himalaya region and the Pamirs, the mountain range across Central Asia, connecting it to China, have 650 hydroelectric programs either under construction or proposed. And those will achieve effects that I suppose not entirely dissimilar, which is to block river systems that will decide who gets access to water and who doesn't. And in the world I work on in Central Asia, for example, the expectation now is that the glaciers in places like Tajikistan will be gone by at least by 2050, possibly before, and 230 million people on the Himalayan plain in northern

India at high levels of water risk. And, you know, in fact, the taking water out of the ground in northern India has been so profound in the last 30 years that the position of the Poles apparently has moved. So, you know, there is a finite limit where if you keep taking from nature, there is the obvious point at which a payback happens. If you keep taking groundwater out of the you drill down boreholes or take water out, you change the water table. And of course, those all can affect the plates that sit underneath. And unfortunately, we're not all born equal. Some of the plates we sit on are more fragile and more difficult than others. And some, they're moving anyway often. But the ways in which those work, I mean, for example, the East

coast of United States, so much water has been taken out in Carolina, New Hampshire, and so on, that there is, again, an idea that the ground has slipped by multiple centimeters over the last 30 years. You know, if you take a lot of water out of things, then you deplete not only the resources, but you can shift the geology of what happens underneath you. And if those plates move, you can have all sorts of consequences. The most obvious is earthquakes, which has tsunami impacts and, of course, the physical damage that comes with it, but presumably the volcanoes which

sit alongside these plates too can get triggered. I think the thing what I'm more worried about volcanoes is that we haven't had a really big one since 1815 when Tambora in what's now, Indonesia went off. It followed two other reasonably sized, but not quite so big eruptions in the previous two, three

years. And that created what's been called the year without a summer because of these atmospheric changes and the fact that had on crops. That made worse the fact that the Napoleonic wars had just come to an end. So many men were being sent back home, being discharged by the army. They weren't being fed by the army anymore.

The pressures on food, the pressures on consumption. And in the case of Britain, anyway, those rains and the inflationary pressures, the price of food going up led to a series of changes that were ultimately quite good for democracy because the people who suffer most in any form of crisis, whether it's economic compression, inflation, cost of living, or climatological or single one-off events, are the people who are the poorest and sometimes the people who are the poor take matters into their own hands and demand change if they're not if those aren't met by by elites and those can be very very bloody then there are other events that could have severe effects on human life on earth the threat of impactors

is also a very real one the asteroid first named 1989 fc passed 680,000 kilometers from the Earth in March 1989. Had it approached six hours earlier, it would have struck the planet. But by far the biggest risk to global climate comes from volcanoes. The clock is ticking, and indeed may be ticking faster than in the past. Recent investigations have shown that volcanism and volcanic activity are closely connected to the melting of ice sheets and to sea level rise, suggesting a causal link between pressure on the Earth's crust and mantle.

If this is indeed correct, we may be facing an accelerated timetable for the next mega eruption that would inject vast amounts of ash and gases into the atmosphere and make discussions about climate change redundant, possibly at the cost of millions, or even of hundreds of millions of lives, as temperatures suddenly cool, harvests fail, and plants and animals'

die. Some estimate the chance of a major eruption before 2100 as one in six. In other words, hundreds of times more likely than asteroid and comet impact combined. The last section of your book was admittedly the hardest to read of the entire book. Fact after fact of what's happening to be to the water, to the air, the land, how it's all being degraded. It's as though I've heard this all before, but somehow not so bleakly. as it is presented by you in this book. You know, how land itself is disappearing, the overfilled landfills percolating with carbon emissions,

oceans being deoxygenized, all of that. I mean, after having gone through this exercise, does it help or hinder your sleep? Well, I suppose, you know, I think my job as historian is not neither to be optimistic or pessimistic, but it's to be pragmatic. I mean, I think because I follow this now, more closely than I did.

When I was growing up in the 70s and 80s, you know, environmental concern was really high up the agenda. I mean, I'm part of a generation that has felt before anxieties about what might happen and part of a generation that sort of avoided that bullet. So I'm sort of sanguine about what science and technology, investment, incentives, regulation by governments, that there can be hoped. And in fact, more than that, those who've catastrophes and prophesied the end of the world since the beginning of time. So far, thank God, have been wrong. So I don't really want to join

my name to the list of people who've been predicting the end of time, although I was with an astrophysicist from Yale a couple of weeks ago who said, yes, she reckons the human life frame is around 150 years top. So that was even worse than I thought. But I think when you follow this day-to-day carefully, you know, for example, there was a water conference in New York where the UN called water consumption globally as a vampiric and warned that 3.5 billion people on Earth experienced severe water shortage for at least one month of the year. And I think we lose that noise. We lose it in the noise, rather, of, you know, who's playing soccer and how's the

World Cup going or, you know, the horrors in the war in Ukraine. There are so many other impulses. So in a way, compression into a chapter that lays this all out. I recorded the audiobook myself for this. They asked me who I'd like to read it, and unfortunately, George Clooney wasn't available. But I had a very brilliant young producer. sitting in the booth who would sort of tap on the glass every time I made a mistake, which is, by the way, it's much harder to read out now,

particularly in 700 pages, then I'd realize. So I get the knock on the window quite often saying, you said this rather than the. And I'd say, sure, no one's going to complain about that. And people will email you. But I got, I was reading the last chapter, and I said, this is what's happening in the world today. You know, research that says that 25% of mortalities in India, Chad and Madagascar

are through air pollution, that he tapped me on the window. And I said, look, I'm sure. said something wrong. He went, no, no, I just need, I actually need to detach. I need a couple of minutes to kind of digest this because, you know, I was aware that this is a problem, but, you know, and then I said, don't worry, you know, I've got some, some good news too. And then I gave him the good news, and he tapped the window again. I went, what, I definitely didn't make a mistake this time. And he just said, look, I'm, I'm just really grateful you put something positive in. You know, those things are really, that they're quite substantial. And I don't really want to

argue about why they're happening or what might happen next, it would seem obvious to me that we need to take some pretty drastic steps. And some of the colleagues I work with here in Oxford and also at Cambridge, their line is that we're well past the idea that we can slow this stuff down or kind of get to a point of carbon neutrality. We need to now be looking at interventions and finding ways of making the polarise refreeze. You know, when you have polar temperatures that are significantly above, in some cases, double digits above where they should be. You know, those changes happen quickly. And, you know, we're quite adaptive as a species.

We're very creative. We're very good at solving things. You know, we did solve the ozone layer when the US and Soviet Union and others in 1987 agreed in your great country, the Montreal Protocol. And there's no reason why we couldn't do that. But of the G20 countries in the world, not a single one had kept its pledges that it had given at the 2015 Paris Accords. Which is surprising. And that would seem to me a problem here in the UK where we don't actually take much energy from Russia. But since the war in Ukraine started, we've built in the UK two land wind turbines. Well, this produces one megawatt of energy.

In Ukraine, they build wind turbines that produce 114 megawatts since the Russians invaded, right? A country at war. So you can do things if you're resourceful. You can do things if you're under pressure. You can do things if you're scared. And actually, you can make good decisions if you're forced to. But, you know, I do think that the thing I've learned, again, the last 10 years, that the single topic that unites every single one of my students of whatever, gender, sexuality, beliefs, background, whatever they're going to do next in the life, one thing that all of them are concerned about is climate and about climate activism and how to have high levels of representation of climate and energy policies in Parliament. And I don't know how to solve that problem.

That's definitely above my pay grade. But, again, what I learned a long time ago is that young people are pretty much always right. You know, young people are very good at identifying problems and demanding change. But, you know, I take my hat off to those who are saying that we, as a generation, haven't done enough because they're right. In your conclusion, you say, and I'm quoting you back to yourself here, on how the climate change problem would be solved, it would be nature rather than human action that ultimately...

It will be nature rather than human action. That ultimately brings net emissions towards zero. It will do so through catastrophic. depopulation, whether through hunger, disease or conflict. With fewer of us around to burn fuel, cut down forests, and tear minerals from the earth's crust, the human footprint may become drastically reduced, and we will move closer to the sustainable, lush paradise of our fantasized past. Perhaps we will find our way back there through peaceful means. A historian would not bet on it. A historian would not bet on it. Peter,

your historian, would you bet on it? Well, I mean, what I don't tell anybody in my book is actually historians are pretty bad when it comes to putting money in the casino. They tend to lose their money quickly. I mean, look, I think that there is a set of circumstances whereby human beings are capable of treating each other with profound kindness and profound generosity and understanding it. Every time there's a humanitarian disaster, you know, Canadian citizens will run to the phone or log on. Absolutely. Give money to people they've never met before, never heard of before and have nothing in. common with at all, you know, face value, apart from their fellow humans who they see

suffering. So, you know, we are capable of those things. But unfortunately, we have a very dark side where we are capable of terrible things too. And, you know, we are no more enlightened than those who've gone before us. But, you know, I think there are lots of things in which we think we're scared. And when you're scared, it's true, you can make good decisions if you have to innovate. So, you know, I'm concerned, I think, about the world as it seems. We do really need to learn how to tolerate people with different views, different opinions, how to show each other and treat each other with kindness every day. And I do think, having written this book, you know, I'm very aware of what a small cog I am in a big wheel.

Our lives, they're gone in a blink. And so, you know, do good and try to encourage other people to learn more, keep studying, and to try to preserve what we've got rather than keep burning. Well, this little cog is an important contribution, and thank you for talk to us about it. Absolutely pleasure. Thank you so much for having me. It's honestly, it's such a pleasure to come and talk about history. I know from your questions, how well prepared you were.

Oh, it was wonderful. Thank you so much. If your listeners, give me a good thumbs up, a good mark out of ten. Please, please have me back one day. Oh, my God. We'd love to have you back. Honestly, there was such a pleasure. Thank you.

Thank you. Bye-bye. Peter Frankapan is Professor of Global History at Oxford University. His multi-award winning book is called The Earth Transformed, an untold history. Our special thanks to the ever-helpful Sharon Klein at Penguin Random House Canada. The web producer of ideas is Lisa Ayuso. Technical production, Sam McNulty. The senior producer is Nicola Luxchich.

The executive producer of ideas is Greg Kelly, and I'm Nala Ayad. And yes, we will get Peter Frankapan back on ideas before the next extinction event. For more CBC podcasts, go to cbc.ca.ca slash podcasts.