Summer reads – Thinking in deep time w/Marcia Bjornerud

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This is Living Planet. I'm Kathleen Schuster, and this is episode four 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 Sam Baker. 

For my staff pick for our summer reading list, I spoke with Marcia Bjornerud, a fellow Wisconsinite, a geologist, and the author of Timefulness: How Thinking Like a Geologist Can Help Save the World.  

I got lost in the folds of time in her book, and it helped me find a new appreciation for something I skipped in school, geology, the study of rocks, but really the story of our planet.  

I chose Marcia's book for a few reasons, the main one being her ability to situate climate change in the Earth's long history in a way that made me feel both gravely concerned about what we were bringing about, while also experiencing a profound sense of calm in knowing that regardless of what we do or don't do, this planet will carry on as it always has, evolving and reinventing itself.  

I found Timefulness to be a deeply grounding read and an accessible introduction to geology, a field I now want to explore further. So, I was delighted when on a recent trip home to Wisconsin, I got to meet Marcia in person. We found some time to walk and talk at a spot she told me was geologically significant and not too far from where she teaches.  

The most bare-naked rock. 

Nice. 

I'm Marcia Bjornerud. I'm a professor of geosciences at Lawrence University in Appleton, Wisconsin. 

And where are we standing right now? 

We're on the top of an outcrop called Poppy's Rock, sometimes called Cactus Rock, near the little town of New London, Wisconsin. And this is a pretty prominent spot.  

We have quite a nice overview over the surrounding countryside. It's one of the highest points around, and yet this rock is some of the oldest rock anywhere in the vicinity. So, it's standing higher than much younger rock. This rock is around 1.7 billion years old, and the surrounding sedimentary rocks are only about 500 million years old. 

How did it end up on top of those? 

Good question. So, it's not really on top, but it is poking up through them. So, the big idea is that this existed way back at the time when the seas that deposited the sedimentary rocks rolled in and began to cover a very ancient, very rugged landscape. Probably this thing was gradually buried. And then as these seas retreated, and Wisconsin was again above sea level for hundreds of millions of years, it became unburied. And now we're seeing the contours of a really ancient landscape that existed more than 500 million years ago. 

Before speaking with Marcia, I hadn't realized just how interesting the history of Wisconsin and the Great Lakes area is in relation to the history of our planet. 

People may not realize it, but the Upper Great Lakes region has tremendous geodiversity, a wider range of rocks in the broad Lake Superior, Lake Michigan area than in the Grand Canyon. So, we have some very ancient rocks, as old as 3.5 billion years, just in the northeastern-most part of Wisconsin and the southern Upper Peninsula of Michigan that record an early continent that we call the Superior Craton that probably formed before plate tectonics really became a habit on Earth.  

We had at least three great mountain ranges here that formed between about 2.7 and 1.7 billion years ago, including the rocks we're sitting on here. And then there was a great episode where North America was almost split in half along what we call the Mid-Continent Rift. This was about a billion years ago.  

Huge volumes of basaltic lava were poured out in a geologically short period of time, and these are best exposed in the Lake Superior region. Lake Superior itself is a glacial feature that formed quite recently, but the basin of Lake Superior is quite ancient. This is the work of the glacier. It's just amazingly smooth. And it's not the ice itself, it's the sand and gravel that are frozen into the base of the ice, acting like a giant sandpaper, just scouring this very hard rock. 

Wow, yeah, it is really smooth. And then it has these like quite jagged cuts going through parts of it. Almost, I mean, some of them are really pretty straight line. 

Right, so in some places, the rock surface is almost mirror polished on a day when it's been raining and when the sun is low, it really almost reflects. And there are... crescentic fractures here, we call them chatter marks, that are also indications of a probably mile-thick ice sheet with sand and gravel and boulders frozen into the bottom, kind of chattering along at the base and fracturing the rock in this way that has left these very distinctive marks that also tell us the direction that the ice was flowing.  

That happened just the other day in the history of this very, very ancient rock, but it's a very, very fine-grained granite. It probably originally formed beneath a great explosive volcano. This kind of rock forms in places like Mount Saint Helens, Mount Rainier, or the great Andean volcanoes that are quite explosive. And so, we're seeing the plumbing system, the magmatic chambers beneath a 1.7 billion-year-old volcanic chain that existed in what is now a very quiet region of Wisconsin. 

Yeah, no volcanoes around here that I know of. Okay, so oceans, volcanoes, ice sheets, this is seen a lot. It's kind of amazing to think of all of the past lives just of this rock, let alone this place here. 

And that is the lens of geology, this understanding that there have been many earlier versions of the world, and there will be many in the future as well. But in some sense, they are still with us. And they define the infrastructure of now. And their stories are astonishingly readable. We can reconstruct these earlier versions of this place.  

My sense is that the past is very much present. It's still with us. It's defining the way we're living today. And I think everywhere, geology is the foundation for the way people live. And if more people knew the stories of where they live, they would have a sense of continuity and connection. 

We know from numerous studies in recent years that experiencing a sense of awe has great benefits for our minds and bodies. It reduces stress, lowers inflammation, and it helps us be more empathetic, patient, and connected to one another. I can't think of much else that's more awe-inspiring than the depth and vastness of time on this planet, especially when you can connect it to the ground right beneath your feet.  

Our planet is over 4.5 billion years old, so about 9 times older than that landscape we were looking at from our perch on the ancient rock outcropping. 4.5 billion years is a really hard number for me to wrap my head around and to find my minuscule human place in it all. One analogy that's often used is if you shrunk Earth's history to the 24 hours in a day, humans only show up in the last second, or fraction of a second really, before midnight. But Marcia isn't a big fan of this popular analogy. 

Yeah, it's ubiquitous in intro geology textbooks, and it's mathematically true, but I think it's wrongheaded for a number of reasons. First of all, it suggests we just waltzed onto the scene from nowhere and doesn't emphasize our deep evolutionary roots.  

Another problem is it sort of is unintentionally apocalyptic. It's like the clock ends at midnight as if there's nothing ahead. There's a deep geologic future ahead of us. And in fact, geologists are more concerned than ever about the future. We're not just backward-looking scientists. We're using what we can learn about Earth's past to understand what its future might bring. And then it also kind of absolves us from any culpability for what we're doing now. If we are just arriving on the scene in the last second, how could we possibly matter to the Earth system? And of course, we are profoundly changing the Earth system.  

So, I find that analogy problematic. I think it's demeaning, too. It makes people feel alienated when they, again, should feel connected. 

To feel more connected to time and our place in it, Marcia coined the term “timefulness,” which became the title of her book. 

It's a deliberate play on both timelessness and mindfulness. So first of all, we like things to be timeless, unchanging. We don't like the experience of loss and the thought of mortality. So that's a natural kind of aspiration. We think, oh, if only things could be timeless. But in fact, nothing is. And certainly when we put on our geological spectacles, we realize everything is the product of time. 

And then the other thing I'm playing with, of course, is mindfulness, which is a good thing, but I think the way that it's sometimes practiced in the West is a kind of narcissistic now-ness, focusing just on the now, not thinking in the longer term, and also kind of cutting ourselves off from the past and acknowledging the influence of history on ourselves.  

So, my whole point with time fullness is developing this habit of mind, which is really what geology is about, of seeing things in four dimensions, including time, and getting a sense for the relative rates of processes in nature and in human enterprise, and making peace with the fact that things do change. And there are many versions of the world. 

And like I said before, those versions of the world can be found right under our own feet, as Marcia showed me. 

Yeah, I also grew up in Wisconsin, like you. I grew up down near Kettle Moraine State Forest, and I remember as a kid learning that it was very hilly down there because there had once been glaciers that came through. And as a small child, that kind of blew my mind.  

But I was wondering about what you think about understanding these past lives of the places we live and how we can do that and how it might help us connect with nature better. 

I've been in this field for so long, it's hard for me not to think that way, but it really does enhance my everyday experience of being a human being on Earth. I can read landscapes. They are legible. They make sense to me. And I think it does create a simultaneous sense of humility, but also belonging.  

I think both of these things are good, affirming things. We're reminded that we're not the whole story, but we're part of the story. And happily, today, there are so many sources of information. Online, people can usually find geological guides to where they live, places where the rocks speak clearly, like here, they're sticking out of the ground, and they're very easily accessible.  

So, here in the States, almost every state has a geological survey, and I know in the UK, the British Geological Survey has lots of free information, maps and guides, and clear explanations. You don't need to have all of the vocabulary to begin to learn to read the landscape. The top here is a very nice place to watch meteor showers. Just lie back, look up at the dark sky. Yeah, but I sometimes think of the journey this rock has had. I sometimes feel like, what would it say? What is the experience of having seen the world change so many times in so many environments. I wish I could speak directly to it. 

Yeah, I guess you don't want to anthropomorphize the rocks, but you would like to know what they've seen. 

And yet they, yeah, they are speaking to us quietly. 

Going back to your concept of timefulness, how can this idea help us think about not only our own place, but in particular climate change and how we deal with it? 

Well, I think it has both practical and sort of psychological implications. The practical one is getting some sense of the rates of change in nature versus the ones that we as humans have accelerated. It's very important to realize that the rate of injection of greenhouse gases into the atmosphere that is caused by us is almost unparalleled in geologic time. That's terrifying to me.  

Some of the great mass extinction events of the geologic past, including the very worst one at the end of the Permian, before the dinosaurs, were caused by periods of unusual volcanism that spewed large amounts of carbon dioxide into the atmosphere. But this played out over thousands of years. We, in the last century and a half, have essentially matched what those terrible volcanoes did all that time ago.  

And the Earth's system was profoundly destabilized for very long periods of time. But we are condensing some of these great crises of the past into a very short period of time.  

So, from a pragmatic standpoint, I think if people understood more the time scales of planetary change, which can be quick and can be unforgiving, maybe that would change our behaviors. 

 But then the spiritual side is, again, having some sense of our place in time and the context of humanity in the larger story of the Earth, for me, is grounding. And I hope to share that sense of being an earthling with people, which I think is a deep existential source of solace. 

So, I know you're a geologist and not a paleontologist. I talk about fossil fuels all the time as a climate reporter, but I think I often forget or don't really think about that fossil part of the phrase. How do you think about that and this connection of this cause of climate change that we have dug up and how that connects to the history of the Earth? 

Right, so fossil fuels are literally the remains of organic matter, mainly microbes living in shallow continental shelf areas, becoming buried in sediment, and then not completely decomposing away, but changing gradually to various types of hydrocarbon compounds.  

And we don't always appreciate that what we're doing is taking millions and millions of years of sequestered carbon that helped, at that time, keep the climate on an even keel by putting away carbon dioxide, essentially. We're extracting that, and in just a matter of a few decades, releasing it back into the atmosphere. We think we're so clever, we find all this energy that's available to us by tapping into those ancient carbon stores, but in the process, we've completely overwhelmed the thermostatic controls that the Earth has had over long periods of time. So, we're releasing the equivalent of hundreds of millions of years of stored carbon in a matter of a few decades, and no wonder there are consequences. 

One of the things I loved most about timefulness was Marcia's ability to put climate change in perspective like this, both its place in Earth's other geological and climatic changes, but also our role in changing Earth's trajectory. I asked Marcia how the climate change that we've triggered compares to past major changes in the Earth's climate. 

Well, change can happen at many different time scales. So, in the main, luckily, Earth does change slowly. That means that we have a stable home that most of the time we can rely on. But sometimes things become destabilized and things can change very quickly. And the great mass extinctions in Earth's history, there are five in the last 500 million years. Only one was caused by a rogue space rock, the dinosaur extinction event at the end of the Cretaceous, and that one probably really did play out in days, weeks, years.  

The other ones were more gradual, not to say they weren't severe, you know, huge percent of existing species wiped out in a geologically short period of time. And those are the ones that I think are more instructive for us. We can see how inexorably there are sort of domino effects or knock-on effects that you destabilize the climate. This begins to change ocean ecosystems. You begin to get dead zones in oceans. And there's just this kind of one ecosystem after another destabilized to the point where the whole global ecosystem is compromised. And those are the ones that to me are the most sobering.  

And most of them have had something to do with destabilizing the carbon cycle and usually spiking temperatures that, again, also lead to ocean acidification and ocean anoxia, things that we are seeing globally today. And so, I'm more disturbed by those non-asteroid related extinctions than the drama of the dinosaur event. 

And I think it's a shame, too, because most of us who maybe only got a little bit of this in grade school or something, the dinosaur one is the only one you learned about or the only one you remember. But these other ones, like you say, are much more instructive to our current moment. 

Yeah, and I mean, it's hard for us to understand things that play out over thousands or tens of thousands of years. But that's part of this geologic habit of mind is stretching our capacity, in a way, for empathy, I think. Being able to think on time scales that aren't going to be directly experienced by ourselves. Every year I teach a course called History of Earth and Life, the 4.5 billion year story of Earth in 10 weeks. It's a completely absurd thing.  

But, in the process, it's like I'm on a trip, a journey with my students, and we get to know the players of any given geologic moment. What was the biosphere like? And we actually do experience kind of this cycle of grief and then relief to know that life did come back. But I think getting some sense of that potential for things to go badly wrong and how they go wrong can motivate people to do better. You can really see the contours of the land. 

Yeah, you know, I think sometimes about if future species are looking around at the rocks on the level we are, or maybe some alien life makes it here, what might they find and what may they think of the traces that we leave behind? 

Most geologists do agree that we have changed the geological rules in a profound way, and looking back at our time, ranging from evidence of a mass extinction to certainly unusual nuclear isotopes that have been produced by nuclear testing, novel materials that just never had appeared before on the surface of the earth, PFAS, the forever chemicals, and whatever might become of the plastics that we have made and other compounds that are just unprecedented in the history of the Earth, evidence of ocean acidification again, the disappearance of coral reefs and subtler geochemical markers of the kind that we can look to in the rock record. 

 We can tell in the geologic past when there have been moments of upset in the carbon cycle, for example. So there are lots of things. Even if we could clean up our act today and live more harmoniously with the way the Earth functions, we will have left our mark pretty clearly, I think, in the rock record. 

It makes me think of, I've spoken to many climate scientists who study ice before and who are talking about, what we need to do by 2100, but they're like, it's going to keep going after 2100. 

Right, but extending our vision by even that much time is a good thing. We have lost a collective sense of where we're going and what we want to leave for future generations. There's an irony to me that as our lifespans individually have increased, thanks to modern medicine, for which I'm very grateful, our visions have shrunken, I think, that we have this illusion as individuals that we're going to be around forever, and we are less connected either to our ancestors or to future generations.  

There's, you know, this terrible irony. Our attention spans are shrinking, and technology is doing this to us, feeding on our worst tendencies to be distracted, rather than to think deliberately about what it will take to create the world of the future that we can all thrive in. 

And it's interesting to me, you bring up our shrinking attention spans. There have been a lot of studies out recently that experiencing awe can really help reduce stress, calm our central nervous system. It has a lot of beneficial effects for our mental health. I was wondering if you think there's a connection here with learning more about geology and as we see young people feeling more and more climate anxiety, if this could be sort of a counterbalancing experience to go after? 

Yes, I certainly do. For me personally, that's true. I find some existential comfort in knowing that the Earth is old and robust and resilient. That's not to say that we shouldn't be concerned, but the Earth has seen earlier crises. The biosphere has never been entirely extinguished for at least 3.5 billion years. The oldest evidence of life we have goes back that far. And that does give me some comfort. 

And that sense of awe, the sense that this is not all about us, is strangely comforting. I think we're so much in our own heads and in our own creations. We've lost this sense that there is great natural intelligence around us that is just waiting for us to be receptive to it. And it's a great relief to know there is this deep wisdom in nature that if we just learn to be receptive, it's there. 

We'll be right back. 

All right, I want to come back to Wisconsin here. As a fellow Wisconsinite, I appreciated the beginning of your book, which starts with snow days. And I remember getting up early and hoping, hoping that my school would be closed. However, every time I come home, it seems that the winters are warmer and less snowy, and that's just in my single, you know, insignificant lifetime. How do you think about this change in a place you're from compared to your understanding of geological time? 

It is striking to me that at the beginning of my training as a geologist, I didn't imagine that I would experience climate change. You know, I was an undergraduate in the early 1980s. And that was really just before we began to realize the magnitude of the effects that humans are having on the planet.  

I've worked a lot in the high Arctic in Svalbard and Ellesmere Island in Canada, and those are places that are really the canaries in the coal mine. They're the places that are changing most rapidly.  

So, I certainly feel it here in Wisconsin, and I feel a sense of loss, but it's been even more obvious in the high Arctic regions. And I feel a real sadness. There are so many cultural traditions that are wrapped up with the climate of a given place. The winter traditions of skiing and sledding and skating. And then there are pragmatic things that just this last weekend, actually, my elderly mother's basement flooded because of the strange new trend in Wisconsin winters of having fluctuations above and below freezing.  

It used to be that by the end of November, it was cold and we got snow and the snow stayed on the ground and the ground got quite cold and frozen. But lately, including this winter, we got a lot of snow, but it kept coming and going, coming and going. And the snowmelt would seep into the ground because the ground never really froze very hard. And so that we arrive in early spring and the water table is very high. And then we got a heavy rainstorm and the water table was extremely high. And so just flooding happened in many people's lower levels in their houses. That just never used to happen.  

And it really brought home to me that this is climate change. This is what it means, is that the way we've built our houses, the presumptions about what we're going to be doing day-to-day in a given month, we don't know what to expect. So, I have a sense of grief, aggravation at having to clean up a mess like that, and frustration that somehow, we can't motivate ourselves to take the action that we need to take. 

You mentioned there kind of the cultural aspects. I think we often take for granted how stable climate has been in human history, which also included evolution of our cultural traditions and things that maybe are in a more graspable past for us, but that those are changing as well. 

Yeah, people don't appreciate that the Holocene, the last 10,000 years, essentially all of recorded history, has been an unusually stable period of time. The Pleistocene, which came before the Ice Age, was actually not just a time of cold, it was a time of a lot of climate oscillation. And then beginning about 10,000 years ago, we came into this much more stable time, and even small fluctuations in global temperature or in regional precipitation often were the things that instigated great times of conflict or migration of people. And so, we've just sort of become complacent and thinking, the Earth is stable, we can build wherever we want and nothing will change. But sea level rise is making it clear that is not the case. So, understanding that the Earth responds and is noticing what we're doing is really essential for our long-term survival. 

One more thing before you go. Remember how this place we were hiking was also known as Cactus Rock? Well, I have never seen a wild cactus in Wisconsin in my life. So, when Marcia told me that there are prickly pear cactuses around this site, I was bound and determined to find some. 

Oh, that's a good one. 

It's like got many little fingers there. 

Yeah. Oh, there's a few. 

I don't know how they make it through the winter. What they do, they kind of just shrink down and... 

Yeah, they look a little shriveled at the moment. 

Look at all these. They're very green, so I have faith they'll make it back. Yeah. 

They're always here. They're very prickly. Again, you just have to respect them. They're pretty hardy. Ow, ow, ow. gosh, they really are prickly. I'm sorry, I did not mean to uproot you. 

A big thanks to Marcia Bjornerud for showing me that even familiar landscapes can hold hidden stories and surprises. She's written a few books on geology, and they sometimes also intertwine with her own personal history. I can highly recommend Timefulness: How Thinking Like a Geologist Can Help Save the World for your next summer book. And hopefully, you can find a bit of timefulness amidst the hustle and bustle of daily life. 

That's all we have for you for this week's show. This was the fourth and final episode 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.