Summer reads – Learning from dinosaurs w/Evan Jevnikar

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This is Living Planet. I'm Kathleen Schuster, and this is episode three of our four-part summer reading series. This year, our team has read a lot of interesting books on the environment, so we decided to interview some of the authors of our favorite picks. You can already find all four episodes in our podcast feed. Feel free to listen to them in any order you like, and be sure to share them with friends and family when you're done.  

Before we get started with this episode, a quick reminder that we want to hear from you. Let us know what you've been reading this summer, when it comes to nature and the environment, that is. You can leave us a voice note at dw.com/livingplanet. There's no need to download or sign up for anything, just hit record. That's dw.com/livingplanet. Thanks. We can't wait to hear from you. Now over to Living Planet's Neil King. 

I chose Surviving Climate and Chaos because I don't really know all that much about dinosaurs. I can never get the names right, except for T-Rex. And what drew me to Evan Jevnikar's book specifically is that it looks beyond dinosaurs as these giant prehistoric creatures and asks what their rise and eventual extinction can teach us about climate change today. It really was that question that drew me in. So, here's my conversation with Evan Jevnikar.  

Evan, welcome to Living Planet. 

Thanks for having me, Neil. I'm glad to be a part of it. 

Evan, before we start, I should say this episode, it has become very, very popular in my house. I have three young boys who are rather obsessed with dinosaurs. I told them I was interviewing a paleontologist about dinosaurs and climate change, and they were extremely impressed. I've never been so impressed with my work ever. 

Well, I'm glad you're going to have a lot to talk about after this. 

I mean, when did dinosaurs stop being just a childhood obsession for you and start becoming a way of understanding the world? 

It's a good question. I feel like it's always been a way to understand the world. I just didn't know it when I was a kid, because when I was a kid, when I first remember liking dinosaurs, it was kind of around the time that Jurassic Park came out. And I know so many paleontologists are like, man, Jurassic Park is what got me into dinosaurs.  

But for me, the one thing that got me in was this documentary that came out around the same time called Walking with Dinosaurs. 

And it was very different than Jurassic Park, where you have T-Rex and velociraptor running after people, eating them. It's just like, just monsters. Walking with dinosaurs was so different in that it showed these as animals. Like they're just, they're big, they're weird.  

We don't see these things anymore, and they have a completely different lifestyle than us. They kind of look like monsters, but they're actually just animals. They just don't look like anything we see today. And I think that framing really set me up as like, wow, I want to learn more about these animals. 

 Another thing I think when it kind of hit of like, oh, I think I kind of want to really lean into this more is when I was in, I think middle school, we had like this weekly thing where we had to give a report on current events. And every week I would always bring up a new dinosaur. And I just thought it was really interesting that like we're learning more about dinosaurs and we're always learning more about dinosaurs. Like we've never hit this thing like, all right guys, let's wrap it up. We've figured it all out.  

Like T-Rex, for example, we know so much about that dinosaur. It's kind of crazy. Like the fact that we know what its vision was like, what its metabolism was like, how it grew. Our knowledge is increasing as time goes on. And I just think it's such a really cool field to be a part of because you're always learning more. 

Most dinosaur stories begin with extinction. This one begins with survival. Around 252 million years ago, Earth experienced the worst mass extinction in its history. Up to 90% of species disappeared. The world that followed wasn't lush or abundant. It was hotter, harsher, and in many places, almost unimaginably hostile. Yet it was in that world that the first dinosaurs emerged.  

What made dinosaurs so remarkably resilient for so long? 

That's such a good question. We kind of see that some of the first dinosaurs maybe pop up around after the end-Permian extinction, which was the worst mass extinction that Earth has ever faced in all of history. Ninety percent of all life went extinct and it created the pretty hostile conditions of Pangaea.  

A lot of people think of Pangaea, they're like, oh, it's just all the continents mashed together, but most people don't think of like what Pangaea was actually like. And it was just this giant global desert where things were extremely hot, giant wastelands.  

We don't find any fossils in that time period in the equator because it was so hot. The first dinosaurs were really good at adapted for like an apocalypse scenario. They are really well adapted to this thing called the Lilliput effect, which is, I think when people hear of extinctions and evolution, it's like, you know, survival of the fittest, the strongest, make it through, but it's actually the total opposite. The biggest ones are the first to go, and all of these really specialized animals, they go extinct very quickly.  

It's actually the small, generalist, omnivore animals that can hide, that don't need to eat much. They're the ones that can make it through these climate crises or just any type of extinction event. 

To put that into perspective, the extinction event Evan's describing there wiped out roughly 9 out of 10 species on Earth. What struck me listening to that answer is how different those first dinosaurs were from the creatures we usually imagine. No giant predators, no towering long necks, just small, adaptable animals, making a living in a difficult world. It's a very different image from the one many of us grew up with.  

Your work, it sits at a really fascinating intersection of dinosaurs, climate science, and human vulnerability, right? And did you always see those connections or did they sort of emerge gradually while researching the book? 

They emerged gradually while researching the book, because this is kind of an idea, like, I'm just going to be clear, like, I did not come up with the idea that climate change affects dinosaur evolution. That's kind of something that's been growing in paleontology already, but in isolated bits, like, we know that climate affected dinosaur evolution in like Asia, and then in North America, in Europe. So, we have all of these isolated incidents, putting all that data together, and then connecting the dots, it really put this grand picture together, like, whoa, like climate change, like it's integral to how this is, and in a way grander way than I had originally thought.  

And so, I actually learned so much just from writing the book. Like, I had an idea going in, but then I feel like I learned more after the book was written. 

One of the things that's easy to lose sight of when talking about dinosaurs is the scale. Tyrannosaurus rex lived closer in time to us than it did to some of the earliest dinosaurs. We're not really talking about a single age. We're talking about almost 180 million years of evolutionary history, long enough for climates to transform, oceans to change, and entire ecosystems to come and go. Which is precisely why dinosaurs make such a useful case study.  

Evan, I mean, you argue, right, that dinosaurs are actually one of the best ways to understand climate change. Can you perhaps elaborate there, why? 

Sprecher 3 

Oh, for sure. Yeah, I think they are. They're like the best case study for evolution for a couple reasons. So one is that they lived for a long time. Dinosaur, if we're not including birds, dinosaurs existed for 180 million years. That is a long time. If you include birds, then it's almost 250 million years, a quarter of a billion years. That is insane. That's a long amount of time.  

And evolution takes a long time to work. So, you have this huge time span to watch evolution change. We have found dinosaur fossils in every single continent. We found them in the North Pole, the South Pole, the equator. We found them on every single continent. So, they lived everywhere, which means they adapted to every type of environment, which is great when you're understanding evolution because it's like, okay, we can see how these animals that all have a common ancestry, we could see how they changed over time and how they enter new ecosystems, how those ecosystems changed their biology, how they adapted to it, who went extinct, who didn't. 

Kids, they tend to see dinosaurs as these, you know, giant, invincible rulers of Earth, predators in many films. But your book almost reframes them as vulnerable to environmental change, too. So I mean, is that part of the lesson here? 

Yeah. Even something as daunting as a T-Rex or like an argentinosaurus, the biggest animals to ever exist, they're vulnerable to climate change. Everything is vulnerable. That's like what causes things to live and die is whether their environment goes away. I mean, we can even see that with just, modern examples, too, is like the dodo bird. Like that just goes extinct. That's a pretty big bird. A dodo bird's pretty specific. It's a very specialized animal. It's subject to extinctions. I know that's caused by humans, but kind of the same thing. Same with woolly mammoths and saber-toothed tigers. Like all these really big animals are charismatic animals that we think from a human's perspective, like, oh my gosh, we're so weak when it comes to nature. But so is all animals. Like it's all life.  

Like everything dies and it's all kind of tied to their ecosystem and how stable it is. But as we just established, the Earth is not stable. In some points it's really unstable and that causes a lot of extinction. So, all life is subject to that. 

We'll be right back after this short break. 

There's a tendency to think of extinction as something that happens to other species. The dodo, the mammoth, the dinosaurs. But the fossil record tells a more universal story. Every species, no matter how successful, ultimately depends on the stability of the environment around it. And that's where the parallels with today start becoming harder to ignore.  

One thing that struck me reading the book is just how familiar some of these climate effects sound. You know, we've got expanding deserts, stronger storms, flooding, collapsing ecosystems. How fair are those parallels to draw these parallels? How close are they? Or is it a bit of a stretch? 

I don't think it's a stretch at all. What I wanted to show in the book was that climate change is not some hand wavy, magical force that we don't know what's happening. Like it's all natural processes, which means if it's all natural processes back then, it's happening right now. And when we think of global warming, we think like, oh, it's this uncontrollable force that's happening. But it all boils down to natural processes.  

And you can see that when you look at around our planet. Like there's this big part in the early Cretaceous where oceans were becoming anoxic. And I was like, and it was explaining like, it's because of, climate change, things are getting hotter, but then a lack of circulation in some areas of, the sea. I was like, wait, we have some parts of our, like the Gulf of Mexico. I'm like, that doesn't have a lot of, circulation. It's kind of like this, you know, Gulf. I'm like, does that have ocean anoxia? And I look into it and yeah, there's actually a lot of ocean anoxia in the Gulf of Mexico. Not as much as what the dinosaurs experienced, but it is there and it has potential to increase. 

And then to your point of like desertification, like I grew up in Arizona, so that's where I was born and raised. So, I know that like deserts, how hot a desert can get. You know, I lived through periods where some days were like 140 degrees Fahrenheit. It's hot. It's really hot.  

So, to me, when I hear deserts expanded back then, I'm like, oh man, that is rough. And then to think about, well, that same thing can happen today. And we're kind of on that course if it is tied to just certain natural processes, like climate increase, global warming, it can happen right now. And it is happening right now. 

One thing I kept coming back to while reading the book was the issue of time scales. Many of the climate shifts dinosaurs experienced unfolded over thousands or even millions of years. Today's warming is happening within decades, and in the history of life on Earth, speed often matters as much as magnitude.  

I mean, this is also something, I think, that a lot of climate skeptics latch on to sometimes, isn't it? That they say, we've had all this before. Climate change isn't anything new. You know, it's not a problem. We'll deal with it, etc., etc. But this is also something I think you brought home really well in your book, the fact that, sure, you know, there were certain episodes or long episodes where the dinosaurs had to deal perhaps with more global warming than we're dealing with right now. But speed is a huge factor, right? What's happening right now is just going very, very fast. 

Yes, yeah. I didn't want to write this book from a doom and gloom perspective to your point of like, oh, dinosaurs went through this. Like, I think that's what skeptics say. It's like, well, life has lived through ups and downs. Like, we're going to make it through. And it's like, life will make it through.  

But do we want to just make it through? Like, do we want, we're not the kind of animals that will make it through mass extinctions, mind you. As I said in the book, like the first dinosaurs were small, just omnivorous, like generalists, and they could hide. That's not us. We are not built for handling, you know, climate crisis. And a lot of animals today are not.  

And so it's kind of understanding like, okay, we're not the kind of things that are going to make it through, but we know that animals can make it through. And when you look at how dinosaurs rebounded after all of these extinctions, you see that like, okay, like there's things that happened that cooled the planet or that warmed the planet up from these cold snaps. And it makes it realize like, okay, if that stuff happens essentially randomly and without any influence. Dinosaurs just had to take it. Like if the climate warmed, they couldn't cool it down. Or if it got cold, they couldn't warm it up. They just had to see who made it through.  

We're actively influencing our climate right now and causing global warming. That's pretty established. So, if we're making it warmer, we can also make it cooler, which is really encouraging that like, hey, we don't have to be like the dinosaurs and just see who makes it through global warming. Like we can actually fix this.  

And it's all based on just the things I talk about in my book of like, expanding green spaces or, carbon sequestration. Like it's all things that we can actively do and break it down into steps that makes it less despair. Like it actually makes it encouraging in a way and hopeful for the future that this is a problem that we can fix. 

You just touched upon it. I mean, one of the ideas running through the book is that climate change doesn't affect every species equally: some collapse, others suddenly thrive and have a bright new future ahead of them. Humans, you already just pointed out, are probably not among those survivalists, these species that are smaller, more general in their approach that we're not going to make it through a kind of extinction event that the dinosaurs faced.  

Hypothetically speaking, how would we have to evolve as humans to make it through? 

To make it through? That's a great question. I think realistically we can't, but let's pretend that we can let’s pretend that we could alter our biology to make it through global warming. We would essentially have to take notes from reptiles and look back to what things were like in the Triassic, because the reason why the Triassic is filled with reptiles is based on a lot of things. Before the dinosaurs, it was mostly the ancestors of mammals that were reigning. Like reptiles were not that big. It was kind of a colder planet at the time, similar to modern day our climate right now.  

But then as things got warmer, reptiles just like crushed it. And that's when we have this diversification of reptiles. And it's called the age of reptiles, the Mesozoic. I know dinosaurs make up most of those reptiles, but predominantly it's the reptiles. And it's because of their lungs. So, we breathe in and out and we have just our, you know, two chambers of our lungs, which is fine for our atmosphere now, but back then it was extremely wasteful because we don't actually absorb all of the oxygen in the atmosphere. We waste a lot of it when we breathe it out because we have to breathe in and then out.  

Archosaurs, which are modern day crocodiles and alligators and birds, which also dinosaurs, they fall into archosaurs. They have what's called a unidirectional lung. So, it's kind of hard to imagine. They still like breathe in and out, but it's like a circle. So, the air passes through, actually it goes through an air sac first, collects oxygen. It sits there, moves to the lung in the next breath, collects oxygen, moves to the next air sac, takes a breath, and then goes out.  

So, they're extracting way more oxygen than mammals do. And then when you pair that efficient lung, with the fact that CO2 is the main driver of climate change, when like an oxygen starved environment that's also hotter, they can breathe better than mammals that are wasteful breathers.  

We would also, not to get crude, but we would have to pee differently. Reptiles have, they don't have the same, you know, excrement as we do, because they also draw in more water. Whatever they're cycling through their digestive system, they're able to extract more water and not lose it when they, go to the bathroom. Whereas we also waste more material, which is good if you're living in a desert. You got to hold on to all that water. It's literally could save your life.  

And then also the fact just minor stuff too, like scales are a little better at retaining water than, you know, our bare skin, you know, condensation and just perspiration. Our skin kind of lets off a little more water than a reptile does, it helps lock it in. Those are kind of the main things. 

If there's a recurring theme in dinosaur history, it's that evolution rewards what fits the world as it is, not necessarily the world as it used to be. The reptiles that flourished during the age of dinosaurs were extraordinarily well adapted to hotter, drier conditions.  

Humans, as it turns out, may be far more dependent on a narrow set of environmental conditions than we often assume. I also haven't found it very striking the way you described in the book. You write that humans are actually dependent on a surprisingly narrow climate niche. It really kind of brought it home to me as well, just what a great window of opportunity we currently have on this planet, the conditions that we have right now.  

Can you perhaps explain a bit more, just how narrow this niche is? 

Yeah, it's surprisingly narrow. I think we think that humans can live everywhere because we currently do. But when you realistically look at the data, there's a study that came out that looked at, you know, the past, I think it was like 50,000 years or longer and looked at like the population of humans. And it found that we cluster towards temperate forests.  

They also looked at like the health of modern countries and they found that some of the healthiest countries were in temperate forests. And so, like Europe, obviously Europe is like a, it's been a hub of like Western civilization for thousands of years. It's because it's a temperate forest. Same with a lot of North America, like the United States.  

Its success is also partly based on the fact that it's a temperate forest. And then also places like Asia, like if you kind of look at the strips of where most of the successful countries, like the more developed countries, it's because they live in temperate forests. And I thought that was really striking. I was like, that's really crazy. And then when you pair that with, oh, climate change affects the distribution of these temperate forests, you know, they recede closer to the poles and they tighten.  

That's not good, that means that countries are going to become harder to live in, the success of countries. It affects like global economics, which is kind of out of my wheelhouse, but the fact that it causes economic changes, it causes global changes in population dynamics. I mean, we see a lot of migration between different peoples and stuff, and that's because of an increase in desertification, because we are naturally drawn towards these temperate forests in a way. So, it sounds so simple, but it's a very interesting and profound thing to kind of realize, like, oh, if we just kind of optimize towards that, or at least try to keep it from shrinking, then that's a great North Star to hold to. 

The final note for the dinosaurs, they were unfortunate in the end, right? Because the event that eventually killed them all, it just happened too fast. It was something that didn't have the time to adapt. But I'm sort of wondering, is there any prehistoric climate event that genuinely gives you hope? 

There's two. One is in the early Jurassic, because it showed that there's a lot of instability in the reign of the dinosaurs. But the early Jurassic was this long period of kind of cooling. And that long period was what caused a lot of the diversification of dinosaurs. We don't get our most charismatic dinosaurs during that time period, but that's when their families were created during the early Jurassic, when there was all this stability. So that gives me hope of like, okay, that's kind of the goal is just to make things stable.  

It's hard for our brains to understand because we're only live for about 100 years. We can't see that far into the future. But if we can expand our time horizon to millions of years, we can create a sustainable ecosystem and environment.  

And then the second thing was that there's this event that happened in the mid-Cretaceous. It's called the Cenomanian-Turonian Thermal Maximum. It was the middle of the Cretaceous and climate change, they went through a serious period of global warming, similar to today. We're going through a lot faster global warming than they did, but it was the hottest that dinosaurs had experienced in almost the entire Mesozoic. So, it reached these huge peaks and it caused a lot of changes and a lot of extinctions, but then it dropped at equally the same. And then things rebounded. And during this rebound, what caused this rebound was the diversification of flowering plants. And so since we know that temperature is tied to CO2 levels, CO2 levels were really high. 

Higher than now, right? 

Yeah, like now. So, we're not there yet. We're, I want to make that clear. If we're not there yet, we're maybe a fraction of the point. We're on track. But those, at that peak, it was actually really good for plants because plants take in CO2 and create oxygen.  

So, it was like a balancing effect of like, it was bad for animals, but then plants just went crazy and they diversified. That's when all flowering plants came around. As plants expanded, green spaces expanded, which then brought in CO2, created oxygen, and cooled down the earth. To me, I see that as like almost a one for one case study of like, okay, this is how we can change things. And it gives me really a lot of hope for today.  

I know it sounds very simple and I know there's probably a lot more that goes into it, but it's a pretty, I don't think it would be a bad idea to plant more trees and expand our green spaces because it's going to help produce more oxygen and cool down the planet. 

Evan, thank you so much for your time and sharing all this fantastic expertise on Living Planet with me and our listeners. 

Thanks, Neil. I really appreciate you having me on. 

Evan Jeffnikar is a paleontologist and a passionate science communicator who combines hands-on fossil research with a gift for storytelling. His book, Surviving Climate and Chaos, should appeal to any species capable of reading. 

That's all we have for you for this week's show. This episode was part three of our four-part summer reading series. You can check out the other episodes by visiting our podcast feed on Apple, Spotify, YouTube, or wherever you get podcasts. And be sure to leave us a review. Thanks for listening.