This article is inspired by a collaboration between the Smithsonian’s National Museum of Natural History in Washington, D.C., and the Field Museum in Chicago, Illinois. It delves into the fascinating concept of “deep time” and how it helps us understand the history of our planet.
Before leaving the U.S. capital, I had the opportunity to witness the construction of the Natural History Museum’s new “Deep Time Hall,” set to reopen in 2019. This exhibit aims to take visitors on a journey from the formation of Earth to the present day, with a glimpse into the future.
To grasp the concept of “deep time,” imagine the Washington Monument as a timeline. At the base, 4.5 billion years ago, Earth was formed. A billion years later, the earliest life forms, single-celled organisms, emerged. The Cambrian Explosion marked the arrival of early animal groups. Fast forward to 232 million years ago, and we see the first dinosaurs. Humans, however, are relatively new, with Homo habilis appearing just over two million years ago and Homo sapiens around 300,000 years ago.
To explore “deep time” further, I spoke with Dr. Kirk Johnson, the Sant Director of the Natural History Museum and a paleobotanist. He emphasized the importance of understanding Earth’s history to make informed decisions about our future. The Deep Time Hall challenges visitors to see themselves as part of Earth’s story and as agents for a positive future.
Dr. Johnson explained that paleontology is about discovery. By studying the past, we gain insights into current issues like climate change. The exhibit uses specimens collected over 200 years, combined with the latest scientific concepts, to present a “future-cast” of our planet.
To further understand the impact of past climate events, I interviewed Dr. Scott Wing, a paleobotanist and Curator of Fossil Plants. His research focuses on the “Paleocene-Eocene Thermal Maximum” (PETM), a significant global warming event 56 million years ago. During the PETM, a massive release of carbon into the atmosphere caused temperatures to rise by 5 to 8 degrees Celsius, leading to ecological changes like ocean acidification and shrinking vertebrates.
The PETM serves as a valuable proxy for understanding today’s human-caused climate change, despite occurring over a much longer timescale. Dr. Wing’s discovery of plant fossils from this period in Wyoming took years of dedicated fieldwork, highlighting the challenges and rewards of scientific exploration.
Dr. Wing emphasized the need to think in geologic timescales rather than human ones. The actions we take today will impact the planet for thousands of years. This perspective is crucial as we make decisions that affect Earth’s future.
Dr. Johnson reflected on the evolution of natural history museums. Originally built during urbanization in the late 19th century, these institutions have adapted to remain relevant in the 21st century. Their mission remains focused on educating the public about the natural world and humanity’s impact on it.
By telling the story of our planet, museums like the Smithsonian aim to inspire visitors to recognize their role in Earth’s ongoing narrative. This educational journey encourages us to consider our responsibilities and the legacy we leave for future generations.
Create a visual timeline that represents Earth’s history as described in the article. Use materials like paper, markers, or digital tools to illustrate key events such as the formation of Earth, the Cambrian Explosion, the appearance of dinosaurs, and the emergence of Homo sapiens. This activity will help you visualize the concept of “deep time” and understand the vastness of Earth’s history.
Role-play an interview with Dr. Kirk Johnson. One student acts as Dr. Johnson, while others prepare questions about the importance of understanding Earth’s history and its relevance to current issues like climate change. This activity will enhance your understanding of paleontology and the role of museums in educating the public.
Conduct research on the Paleocene-Eocene Thermal Maximum (PETM) and its implications for modern climate change. Prepare a presentation to share your findings with the class, focusing on the ecological changes during the PETM and how they relate to today’s environmental challenges. This will deepen your knowledge of past climate events and their relevance to current issues.
Engage in a debate about the importance of thinking in geologic timescales versus human timescales when making decisions that impact the planet. Use evidence from the article and additional research to support your arguments. This activity will encourage critical thinking and a broader perspective on environmental decision-making.
Participate in a workshop where you create a “future-cast” of our planet, inspired by the Deep Time Hall exhibit. Consider current scientific concepts and potential future scenarios. Discuss how understanding Earth’s history can inform our actions today to ensure a positive future. This activity will foster creativity and forward-thinking in addressing global challenges.
This episode is brought to you through a collaboration with the Smithsonian’s National Museum of Natural History in Washington, D.C., and the Field Museum in Chicago, Illinois.
[Emily VO] Hey, so my time is almost up here in the U.S. capital. But before I left, I had a chance to sneak in and see part of the construction of the Natural History Museum’s new “Deep Time Hall,” which is reopening in 2019 after being completely overhauled and rebuilt over the last five years. When it’s done, visitors will be able to learn about the history of our planet from the formation of the Earth to present day, with a look to the future.
To help us understand this concept of “deep time,” let’s use the Washington Monument as a scale bar. Here’s the formation of our planet, down here at the base – 4.5 billion years ago. The earliest evidence of life took the form of single-celled organisms around a billion years later. Then, the first multi-cellular life shows up. Very early animal groups join the party during the Cambrian Explosion around here. Oh, and here’s our friend Dimetrodon, who, by the way, is not a dinosaur. But around 232 million years ago, we get our earliest dinosaurs, and they largely get wiped out by an asteroid here. The first known flowering plant is pretty late to the party, but honestly, so are we. The earliest humans, Homo habilis, evolved a little over two million years ago. And Homo sapiens didn’t make it on the map until just around 300,000 years ago, right up here.
To get another perspective on this concept of “deep time,” I went to chat with Dr. Kirk Johnson. He’s the Sant Director of the Natural History Museum and a paleobotanist. He studies fossil plants and has been working on the Deep Time Hall renovation project for years.
Emily: So, how do you deal with that interplay between technology accelerating at an unprecedented rate, but you’re focusing on a Deep Time Hall?
Kirk: We live in a world where it’s not just changing, but the rate of change is changing, which means that this Hall has to be future-proof to some degree. And what we’re doing is actually challenging our visitors to see themselves in their part of the story of our planet, which is what other halls don’t do, and also see themselves as agents for a positive future of the planet.
Emily: How do you do that? I mean, you as a paleontologist – you’re constantly looking at the fossil record, your work is in the fossil record, your research is looking at things that went extinct or died tens of millions of years ago. How do you take your background as a paleontologist and interject that into this idea of looking to the future to make decisions that are going to be better for our planet?
Kirk: Well, I mean, paleontology is all about discovery. You’re looking for things, and you find things, and that’s what’s so cool about it. And for me, it’s really helpful to know the history of the planet because it helps me understand what’s going on now. Take climate change, for instance; we know a ton about climate change by looking at what’s happened in the past. And for almost all the stuff we’re presenting in the exhibit, we’re using specimens that we’ve had for 200 years, but concepts we’ve had for as little as 10 years. So the science that’s going through this hall is the latest science, and it’s got this “future-cast,” which is quite amazing.
[Emily VO] On the topic of both the discoveries in paleontology, as well as looking to the fossil record to better understand current climate change events, we went to interview the Curator of Fossil Plants, Dr. Scott Wing. Like Kirk, he’s a paleobotanist, but his research is focused on something called the “Paleocene-Eocene Thermal Maximum,” or the PETM for short. Simply put, the PETM was a massively significant global warming event that happened around 56 million years ago, or about here on the Washington Monument. During the PETM, something triggered a huge release of carbon into the atmosphere that lasted for a few thousand years, and it significantly warmed the planet. The global temperature increased by five to eight degrees Celsius or around nine to fourteen degrees Fahrenheit. This led to a variety of ecological and environmental changes. There was ocean acidification and deep-sea extinctions. On land, many vertebrates began to shrink in size, as the CO2 in the atmosphere caused plants to become less nutritious. And there were other floral and faunal changes occurring, as sea levels rose and the planet became warm and wet. The PETM lasted for around 180 thousand years. And although the impact of the PETM carbon release happened over a period of time that’s a hundred times longer than the human-caused carbon release that’s happening today, it’s still the best proxy for helping us understand the long-term effects of today’s human-caused climate change on our planet. But there’s still a lot of work to be done. And as you’ll hear from Scott, it can take years to scratch the surface.
Emily: How was this event even discovered?
Scott: Well, it was discovered initially in drill cores from the Southern Ocean off of Antarctica. Antarctica is where the coldest, densest water in the ocean forms today, and that really has a huge influence on the circulation of water in the global ocean. So the question was, how long has that been true? Has that been true for millions of years? What about back when it was generally a lot warmer than it is today? So, you have to imagine a big drilling ship, a bunch of scientists on board, and labs – they’re bringing up cores. They were there to get a sort of long-term record of what happened over the last 70 million years. And what they had noticed was there’s an extinction event that they didn’t really expect to see. So, people published papers on these cores from Antarctica. The next year, a couple of other scientists working in Wyoming, where I had been working for a long time, said, “Oh, we see what we think is the same event in rocks deposited on land in Wyoming.” I thought, well, if there’s a warming event, I work on fossil plants – plants are really sensitive to climate change – I should go find plant fossils in the period of time when there was that sudden warming because that’s going to be really interesting.
Emily: So how did you find these fossils? Did you just get out of your truck and walk 20 feet in the other direction, and boom, there they were?
Scott: No, no. Yeah, that would have been really nice. I knew sort of about what level I was needing to look at, but I didn’t know exactly where, and I didn’t know where the plant fossils would be because I hadn’t looked for them exactly in that zone. This warm period is about a hundred thousand years long. A hundred thousand years sounds like a lot, but it’s a hundred thousand years in the middle of a pile of rocks in that part of Wyoming that represents about ten million years. You know?
Emily: You’re looking for a tiny sliver.
Scott: It’s the needle in a haystack.
Emily: The needle in the haystack, a PETM fossil deposited in the Big Horn Basin in Wyoming.
Scott: Right.
Emily: That’s a less relatable analogy.
Scott: Just a little bit, yeah.
Emily: Not that people are finding needles in haystacks, right?
Scott: Yeah, so I set out looking for them. That was 1993. I went out every summer for the next 10 years.
Emily: It took you 10 years?!
Scott: Yeah, well, 10 years before I found an area where it looked like there were going to be plant fossils, and then it took another two years to find really good ones. I mean, there were other things too. I wasn’t just wandering around like a crazy person lost in the desert, saying, “Where are my fossils? They must be here someplace!”
Emily: So, what was this moment of discovery like?
Scott: It was very storybook. I was out with a guy who just graduated from college, and he had never been in the field before. And so, we walked for a couple of hours up into these hills where I knew the rocks would be the right age, in general. I said, “Oh, you know, I just need to check that out,” because I saw something that looked like maybe the right fossils. I dug into the hillside with a shovel, and out pops a little plant fossil. It kind of looked like this, and I knew immediately I had never seen anything remotely like it. I get down and I’m digging with the shovel on my knees, trying to see what else is in there. Out pops another leaf! I just started to laugh because this is absurd, because it was exactly what you’d expect! So I started laughing, and then I started to cry because I was really happy! And then I remembered that I wasn’t by myself.
Emily: [laughs]
Scott: I had kind of forgotten that I had somebody with me because it was very exciting! In science, I had not had many “Eureka” moments, you know that sort of, “Oh, that’s it!” That doesn’t really happen very often because it’s usually more incremental. So you usually sort of slowly realize something. But no, no, it was like 4:04 p.m. on July 3rd, 2005.
Emily: [Sarcastically] It’s not like you committed that date to memory?
Scott: Yeah. No, I did. Yeah, that’s actually it.
Both: [laugh]
Emily: So what did you do with that information? I mean, because now the search is over and now the work begins.
Scott: Right, exactly! Well, we made a big collection. That took two years – two summers of work because that’s what it takes.
Emily: Rocks are heavy.
Scott: Rocks are heavy, they’re hard, they’re fragile. So then I spent basically another 10 years looking for more places.
Emily: Why is this a significant climatic event in our Earth’s history?
Scott: It is the closest thing we have in the geological past to what we’re doing right now. Along with the warming, we have really strong evidence for a huge release of carbon into the atmosphere. We think that the carbon release may have been triggered by volcanic activity. It’s quite possible that that triggered the release of other reservoirs of carbon. And then you change the climate, and you may start to cause the bacteria in soils to get very happy because it’s warmer, and they eat more of the organic matter in soils, and that puts even more CO2 in the atmosphere. So basically, it’s a train wreck and it just goes “pew,” and that’s why it warms so quickly. Today, carbon release is a little bit simpler. It’s mostly caused by burning fossil fuels. Fifteen percent of it is caused by deforestation and land-use activities of humans. Except, what’s happening now is happening even faster.
Emily: How does it resolve itself? Does it resolve itself?
Scott: After about a hundred and fifty thousand years of being really warm, it starts to cool off again. A combination of weathering and productivity are pulling the CO2 out of the atmosphere.
Emily: So at one point you mentioned that it’s important for us to think in a geologic timescale, rather than thinking in a human timescale, especially as there are policies and other decisions being made today that are contributing to the overall warming of our planet. What does that mean to think about a geologic timescale versus a human timescale?
Scott: Yeah, I think it just means to be aware. We can’t just think about next year, or ten years from now, or a hundred years from now. Because the things that we’re doing today are going to have an impact in a hundred, or a thousand, or 10,000 years. It’s really like “Spider-Man.”
Emily: Really?
Scott: Yeah, you know, well…
Both: “With great power comes great responsibility.”
Emily: It’s true.
Scott: Yeah, and there’s the time dimension to that responsibility.
Emily: So what does this mean for the Natural History Museum’s looking to the future?
Kirk: I mean, if you think about it, these museums all were built during the time of big urbanization between 1880 and 1920. So at the end of the 19th century, was the formation of the big temple-like buildings in urban areas. And people are moving into the city, away from the countryside. They were learning that there was stuff to be preserved, like herds of bison were disappearing, and people naming National Parks. And then the 20th century happened! The 20th century went by fast, but it had the World Wars, it had the Depression, it had the Cold War, it had Sputnik, and it had the rise of science centers. And all that time, the natural museums got lower and slower, and lower and slower, and lowered. So by the early 80s, they looked like 19th-century institutions, but they weren’t because they were these places where families worked to learn about the natural world and people kept going. So they really are 19th-century organizations that are dialing forward into the 21st century. And our message is the same, but changed. Right? The same because we’re really worried about the natural world and humans’ impact on it. That was our original mission. It’s our mission now. And we’re trying to prepare people to realize what the impact of humanity on the evolution of their planet is. And this is how we do it: by telling the story of our planet and then making them realize that they’re part of that story.
Emily: I’m convinced.
Kirk: Okay, good, done.
Emily: Yeah, you’ve got my money, but you’re a free institution.
Kirk: Oh, that’s right, but we’ll still take your money.
Emily: [laughing] Okay?
Emily: It still has brains on it.
Deep Time – A concept in geology that refers to the vast time scale over which geological and biological processes occur, often spanning millions or billions of years. – Understanding deep time is crucial for comprehending the slow processes that shape Earth’s landscapes and life forms.
Paleontology – The scientific study of the history of life on Earth through the examination of plant and animal fossils. – Paleontology provides insights into how species have evolved and adapted over millions of years.
Climate Change – A long-term alteration in Earth’s climate, often due to natural processes or human activities, affecting ecosystems and weather patterns. – Researchers are studying the impact of climate change on polar ice caps and global sea levels.
Fossils – The preserved remains or impressions of organisms from the remote past, typically found in sedimentary rock. – Fossils of ancient marine creatures can reveal information about Earth’s prehistoric oceans.
Ecosystems – Communities of living organisms interacting with their physical environment, functioning as a unit. – The health of coral reef ecosystems is a critical indicator of marine biodiversity.
Carbon – A chemical element that is a fundamental building block of life, playing a key role in biological processes and Earth’s climate system. – The carbon cycle describes how carbon is exchanged between the atmosphere, oceans, and living organisms.
Vertebrates – Animals with a backbone or spinal column, including fish, amphibians, reptiles, birds, and mammals. – The fossil record of vertebrates provides valuable information about the evolution of complex life forms.
Geologic – Relating to the study of Earth’s physical structure and substance, its history, and the processes that act on it. – Geologic formations like the Grand Canyon offer insights into Earth’s ancient environments.
Natural History – The study of organisms and environments, focusing on observation and description of the natural world. – Museums of natural history often display specimens that illustrate the diversity of life on Earth.
Evolution – The process by which different kinds of living organisms develop and diversify from earlier forms over generations. – Evolutionary biology seeks to understand the mechanisms that drive the diversity of life on our planet.
