Science Friday - COVID-19 Factcheck, Digital Earth Day, City Nature Challenge, Ancient Antarctic Forest. April 17, 2020, Part 2

Episode Date: April 17, 2020

Can Coronavirus Reactivate In Patients After Recovery? These days, newsfeeds are overloaded with stories of the coronavirus, but Science Friday continues to explain the science behind COVID-19 headlines. Here, we learn about South Korea reports of 116 patients who recovered from the disease tested positive. Angela Rasmussen, associate research scientist and virologist at the Columbia Mailman School of Public Health, breaks down how reactivation works in viruses in diseases such as herpes. Plus, Rasmussen talks about human challenge trials—where participants are given a vaccine and inoculated with a virus—and the debate over the usage of these trials to develop a COVID-19 vaccine. Earth Day Goes Digital Next Wednesday is the 50th anniversary of Earth Day, marking five decades of environmental actions, like community cleanup, planting trees, or marching in the streets.  But this year, coronavirus has led to the cancellation of planned marches and large-scale events. Instead, many people will be participating in a digital Earth Day. Ira talks to Kathleen Rogers, president of the Earth Day Network about what people can do to participate, parallels between climate change and coronavirus, and environmental action in the age of the Trump administration.  Uncovering Antarctica's Rainforest Scientists found 90 million-year-old evidence that Antarctica wasn’t always a snow-covered continent. New ice core research provides evidence that the frozen land was once a temperature rainforest. Marine geologist Johann Klages, an author on the study, discusses what temperature the Earth would need to be to support such an environment in Antarctica, and how that can be used to create more accurate climate models.  Show Off Your Backyard Birds And Bugs Get involved in Citizen Science Month by snapping pictures of nature from your backyard with City Nature Challenge.  Subscribe to this podcast. Plus, to stay updated on all things science, sign up for Science Friday's newsletters.

This is Science Friday. I'm Ira Plato. Later in the hour, we'll talk about the 50th anniversary of Earth Day. It's next Wednesday and due to coronavirus. It'll be a digital day of action. Just to note that we won't be taking your calls during this pre-recorded hour of the show. First up, as the COVID-19 pandemic progresses, so does the speculation, the glut of data, articles and studies coming out about the virus. Well, all the stories coming out on Twitter and Facebook and social media, it can be hard to sort through the fact from the rumor.

So we want to help you fact check your feed and sort through the stories. Last week, there was a story about the risk of runners and bikers spreading the virus. And this week, a report from South Korea about the reactivation of the virus in COVID-19 patients. So how do these stories hold up? And what do they really tell us? My next guest is here to help us sort out the details. Dr. Angela Rasmussen, Assistant Research Scientist, and virologist at the Columbia Mailman School of Public Health.

Dr. Rasmussen, thanks for joining us again. Thanks for having me back, Ira. Can we start with the South Korea item where there were 116 patients who reported recovery from COVID-19 but later tested positive? There's this idea that the virus was reactivated in them. What could be happening there? I'm not clear that these so-called reactivations now are that much different than what a couple weeks ago people were reporting as reinfection.

In all of these cases, there have been these reports that are not supported by data from what I have seen in any case that suggests that patients who have tested negative are then testing positive. You know, I certainly can't rule out the possibility that these patients are actually being re-infected or that the virus is somehow reactivating from being in a latent or sort of dormant state. But I think a more likely explanation is just that the test does have a certain percentage of false negatives that it can give. And we do know that people after recovering can continue to be positive for the virus's RNA or its genetic material. There are a number of viruses for which viral RNA can be

found long after the patient has recovered and they don't actually have any infectious virus. And a recent paper that was just published studying some patients in Germany does suggest that after recovery patients do have these sort of fluctuating levels of viral RNA that can still be detected in their tests, but that doesn't mean that they are actually reinfected or reactivated or potentially still shedding infectious transmissible virus. So it's not something like herpes that stays in your body and comes back and goes away every now and then? That's correct. So herpes viruses have a very specific mechanism that allows them to basically turn off most of the viral genes and exist as sort of a genome, an epizome, we call it, outside of the normal host cell genome. Then when there's a stress or some kind of incident that provokes the virus to fire up its genes again, start expressing viral proteins that virus can reactivate.

Coronavirus don't have any type of mechanism that's known to have a latent period or reactivation events. And I would be very surprised if this virus did as well. We don't have any reason to think it's different from many other coronaviruses. There's a lot of talk about patients recovering and developing an immunity to the virus. How are these things related? So we still don't know that much about protective immunity to the virus. What we do know is that experimentally infected animals that have been allowed to recover can't be infected with the virus, at least in the case of a study that was done in

recess macaques or monkeys. We also know that patients who have recovered from COVID usually have tithers that are detectable of what we call neutralizing antibody. So these are antibodies that can bind the virus and enactivate it or render it non-infectious. Not every patient does have detectable antibodies, but it really is a minority of the patients that have been studied so far that don't have antibodies. So the evidence thus far does indicate that most people will develop an immune response. We assume that that's protective, but we need to do more work to find out exactly how protective it is and how long that protection lasts. There are reports that COVID-19 patients will show signs of

improvement, and then they'll just crash. The cycle repeats itself, and it's due to something called the cytokine storm. What is the cytokine storm? So cytokine storms are essentially an overreaction by the body's immune system and specifically inflammation. What happens in some patients that we don't understand is that the immune system will really overreact. So normally when you're infected with a virus, the inflammatory processes are really important to tell the immune system where to go to contain and clear that infection. The cytokine storm is when the signals that are needed to coordinate that type of response essentially lose all ability to be controlled. So rather than giving calm directions on how the immune system should go, it's more like every inflammatory

process is shouting all at the same time. And so it's essentially immune or inflammatory chaos, and that can trigger this disease that's actually more serious than what the virus itself causes. Yeah. Does the storm, the cytokine storm, play any role in developing treatments or vaccines? So certainly people have talked about using a drug called Tosilazumab. I hope I'm pronouncing that correctly. What that is is an antibody that targets a molecule called IL-6. And IL-6 is a very potent pro-inflammatory cytokine. So it's a message that cells give to say, hey, like, let's turn on inflammation. By treating with Tosilizumab, you reduce the amounts of IL-6 so that really potent part of the cytokine storm, hopefully you could reduce inflammation as well.

I believe that's only been used so far in compassionate use circumstances, so uncontrolled, essentially uses of that drug. But I would not be surprised to find out that there are clinical trials being set up and underway to test that out. Right. Now, let me run a story by you that came out last week that was getting shared. And it was about a Belgian report that looked at how run runners and bikers might spread the virus. But this wasn't exactly a study. Where did this report come from? My understanding of this is a Belgian scientist or engineer who studies aerodynamics

did this model of how droplets spread in certain circumstances, such as when people are running. And this was, I believe, first covered in a Belgian magazine. There was obviously a lot of attention paid to it. People were very concerned that it meant that if you went running, you had to have at least 26 meters, I think, of space between you and other runners to avoid being exposed to respiratory droplets that could potentially be infectious. But there was no paper and no data that was released to show how this model was developed. The original magazine article that this was described in was then translated into English

and released by the author as a white paper, which is typically not what scientists usually think of when they think of a white paper, which is usually a technical description of a study or a model. To my knowledge, it hasn't been published anywhere, so it hasn't undergone peer review, and I would be very skeptical of these findings because they don't really take into account anything that we know about how viruses are transmitted. It really is just a model of how droplets spread through the air. Now, let me move on to another topic that was in the news or circulating. We know that COVID-19 attacks the lungs, and some researchers have been comparing this to altitude sickness and looking at treatments for altitude sickness. What's the rationale here?

Is there an overlap possibly? So the rationale there is that some physicians have made the observation that this pneumonia that COVID causes, is, does not look like typical pneumonia in which the lungs are filled with fluid and there are actually mechanical problems with breathing, which is what mechanical ventilation, of course, helps with. In this case, it appears that some COVID patients at least have lower levels of oxygen in their blood. So this is an issue less of the lungs aren't working properly than there's not enough oxygen getting into the blood. And that looks a lot more like high altitude sickness. but it's really unclear that this is the case for every single patient.

Some of this is based on the fact that not every patient who's put on a mechanical ventilator really has a great outcome and patients are unable to get off these ventilators. But I think this has just recently been appreciated. So a lot more work needs to be done to determine exactly what's going on in these cases. One last question for you. We know there's a scramble to quickly come up with a vaccine. and one way to fast track this is through human challenge trials. What happens in one of these trials?

Is that a recommended way to try out a vaccine? Well, it's certainly a hot topic of debate right now among scientists and physicians and bioethicists. Typically, human challenged trials are not done to test vaccine efficacy, at least not until they've undergone extensive preclinical testing and animals. This is really an emergency situation in which that's even being considered. But what happens in a human challenge trial is you would vaccinate human subjects who volunteered to be essentially guinea pigs to test the vaccine. And then you would challenge them with a dose of the virus. That would be enough for them to get infected. But ideally, and this is where the problem is, it wouldn't kill them.

The problem is we don't know what really all of the risk factors are for getting severe. or COVID, and we don't know what dose, what effect dose has on disease severity. So it's a really tricky ethical question that I think is going to have to really undergo a lot more consideration and debate before we do it, because the last thing we want to do is test a vaccine and ends up causing a lot of injury or potentially even killing trial subjects. Some of the first polio vaccine trials, which were done on essentially mentally handicapped children in institutions, the Willowbrook institution. The idea of human challenges for vaccines, I mean, they haven't really been done since like that, which is obviously unethical to do those types of experiments. You know, I mean, I realize

we're in a desperate situation here, but I can just see so many outcomes of a human challenge trial going spectacularly and horribly wrong, that I personally am not in favor of them, although, you know, people are bringing these ethical arguments to try to minimize risk and justify it that way. So we'll see what happens. Thank you very much for clearing all of this up for us, Dr. Rasmussen. It's always a pleasure to be here, Ira. Thank you. You're welcome. Dr. Angela Rasmussen, Assistant Research Scientist and Virologist at the Columbia Mailman School of Public Health. This is Science Friday. I'm a Ira Flato, next Wednesday is the 50th anniversary of Earth Day, 50 years of action and organizing,

whether that's a community cleanup, planting trees, or marching in the streets. Incidentally, it's also a special day to me as it's my personal anniversary, too. It marks my first story as a science reporter on that first Earth Day many years ago. But not about me. This year, coronavirus has led to the cancellation of planned marches and large-scale actions. so instead many people will be participating in a digital Earth Day. Here to talk about that is Kathleen Rogers, president of the Earth Day Network. She's based in Washington, D.C. Welcome, Kathleen. Thank you, Ira.

The theme for this year's Earth Day is climate action. What are some of the things people can do while they're practicing social distancing? Well, I think, you know, one of the ironies about the pandemic is that many of our activities, we're already geared for a digital world because we're in 192 countries and we have to prepare to send materials to people and get them engaged wherever they are. So we have a variety of actions depending on your demographic and station in life. So if you're a teacher and you're doing online activities, we have downloadable history of Earthdays, work plans, and a number of other activities that you can conduct with your students, whether you're K through 12 or even at the university level.

We certainly have dozens of petitions and opportunities for you to get engaged civically, whether it's committing to vote or sending letters to your representative or your country leader. So we prepared for many things to go digital. Perhaps our most important digital campaign is Earth Challenge 2020, which is a group effort of the U.S. State Department, the Wilson Center, Earth Day Network, and literally thousands of science groups. around the world all joined together to build the largest open source citizen science database in the world, which allows you to take a photo of either the sky or of plastic pollution and upload it to a

map where you'll see yourself and millions of other people participating. But it has the twist that it allows you to take a civic engagement action in your own language and relevant to your own country. So that's a big move for both the citizen science community and others to connect citizen science to civic engagement. And that is entirely digital. Yeah, we're really big on citizen science and engagement. But I've got to imagine because this is a special 50th anniversary day that you had all kinds of big plans and all kinds of celebrations that had to be scrapped. Gotta be disappointing. It is.

I think my inconvenience and sadness about the 50th anniversary is real, although tempered entirely about the worry and concern I have and people at Earth they have about families, food, jobs, and survival. But this was a setback, both from a climate perspective and in our goal to build the world's largest citizen science movement in the world. So do you think that spending Earth Day digitally will have the same impact as, say, spending the day marching or doing a city cleanup? Well, a lot of those activities have been moved. So the great global cleanup, which had almost 500 million people signed up to work on it,

has been moved till September. And that's sort of a knock on wood at this point. And, of course, the fall marks a very politically active moment in the United States as well. So I think the knitting together of the movement is the point where it feels a little precarious because so many people had been revved up and excited about. the 50th anniversary, which wasn't just a day. It was months of action. But that will go on just at a different time, maybe on our half birthday. Your half birthday, yeah. It's interesting you bring up politics because it seems like quietly in the background of the coronavirus pandemic,

the administration is rolling back a lot of environmental regulations that have come in effect since Earth Day and because, you know, her birthday. I mean, Earth Day is definitely credited with having started the modern environmental movement and most of our landmark laws were passed in rapid succession after the first Earth Day in 1970. And the environmental movement as nascent and new and ill-formed as it was back in 1970, really enjoyed a bipartisan, corporate, even honeymoon that lasted a couple decades. And since then, it's been two steps forward one step back and then you have the climate change is a relatively new issue at least in terms of activism in the last 20, 25 years. But we have experienced lately a sort of new turn where

almost every part of the environmental protection fabric is being unwoven and little by little, even under the cover of COVID-19, it seems to be continuing. And no environmental law has or even process or regulation has been left untouched. I do think and believe in human nature generally and our wisdom. So I think that you'll see over time most of those important laws be regenerated or come back to life. But for now, we're all super busy. Yeah, you think people are making little place marks in their lives. We'll, you know, this is not on the front burner. Let's put it in the back burner for a while, but we'll get, we'll get back to that. Yeah, and there's certainly people are drawing parallels left and right between the pandemic and climate change. And the question is,

is now the right time to be talking about it. And there's certainly parallels. I mean, Earth Day was built on science. It was that bright line that everybody crossed between thinking about environment as a conservation of species and national park movement. So one that was based on protecting human health. And it was that science of 150 years of industrial development and polluted air and dirty water, toxic exposure that drove 20 million people out of the streets to take part in that first Earth Day. So is it a question of time of drawing parallels? I think around two issues. One, the belief in science and trust in data. That's certainly a part of both the coronavirus and Earth Day and climate change and what I do for a job. And I'm

And also the need to prepare for potential disasters, both the virus and climate change are certainly two good, big indicators that we need to be prepared. So while we appreciate the news of cleaner air and clean water and of wildlife filling our now empty spaces and a definitely quieter world, and we all long to get back to normal, I think there'll be a time when we can reflect on a cleaner, quieter world

that we're witnessing and experiencing and the need to heed the very clear warnings of the data we have and have had in our possession for years. And the need to prepare, just as the pandemic taught us, that it's life-altering capacity will be weighing on our minds and give us the sort of impetus to move forward. I want to play a clip from Dr. Ayanna Johnson. She's a marine biologist and climate activist, and she's one of the forces behind a green economic stimulus plan that was unveiled in March. That proposal would create green jobs and accelerate the U.S.'s transition off of fossil fuels. She and her team are pushing Congress to back this plan.

This is going to go on for a while, right? Like this pandemic, we don't know when things will be get back to normal or what the new normal will be. And so it takes time for these ideas to percolate into the policy. And so we just wanted to make sure that, these ideas and solutions were on the table. What do you think about this idea that even though we're dealing with coronavirus, that the time to act on climate action is still now? It's obviously weighing on everyone's minds that we have to go back to normal, whatever normal will be.

And the economy is critically important to every one of us, whether you're looking at your retirement savings disappear or you don't have a job at all or know if you'll ever get one back. So while it's critically important not to let everything go and we're watching what's going on with our laws and regulations, I do think that we will arrive very shortly at a time where we can start talking about how we rebuild the economy in a way that's greener, more forward thinking, more resource conscious. And so I don't think it's off the table, but I am also aware that for almost everybody in America, no one is sailing through. this unimpacted. And I want to be very cognizant of that and cautious about talking about new taxation, new changes to the government when people might reject them wholesale. But if we slowly but quietly

introduce some of these major concepts about how we rebuild, how do we create new green jobs, how do we stay on top both as a global power, but also as a more conscious and careful country. I think the time will come fairly soon. Are you surprised by how active the youth of the world are in this, considering, you know, there are groups like Fridays for the Future and the Sunrise Movement and Greta Thornburg and people like that? I mean, they have really taken this on themselves. No, it's really amazing. And because I've been in the environmental movement 25 years, I've seen multiple generations of young people come forward.

We used to house many of them in our own office building. And we've seen this repeatedly. But I think this movement is different because there's so many pieces and arms and groups engaged collectively in climate change. And I love that they have a take no prisoners approach. I certainly was like that. And I can tell you my late teenagers, early 20-year-olds are like that themselves. And so I appreciate what they're doing. I know that a lot of them put themselves out there.

They sit in front of the UN like Alexandria v. Signore and Greta did for years. And so that's really amazing. And it's also age appropriate that they're putting themselves in a situation where they're both having to juggle school and being teenagers, still not able to vote. And they're able to sustain it. So I'm proud to work with them. And I'm glad they're finding avenues for engagement. Thank you very much, wishing you a very successful Earth Day, Kathleen Rogers. Thank you so much for having me.

Kathleen Rogers, president of the Earth Day Network, based in Washington, D.C. After Earth Day is over, you might still have the bug for going outside and exploring the nature that's in your backyard or hanging out outside your window. And, you know, you can find joy in this. strange time by snapping a picture of a blooming flower or a buzzing bumblebee and sending those to the City Nature Challenge. It's a citizen science project taking place all over the world. And all you needed to do to participate is a smartphone and a sense of curiosity. Leila Higgins is one of the founders of the City Nature Challenge. She's based at the Natural History Museum of L.A. County in Los Angeles. Welcome. Hi, Ira. So tell us.

about the city nature challenge. What information are you trying to collect? So we started back in 2016 as a competition between L.A. and San Francisco, which city could find the most nature. We know that urban areas are kind of understudied on the biological side. And so we thought it would be a fun way to celebrate the very first National Citizen Science Day back then in 2016 to try and fill in those data gaps in the urban spaces. And it's kind of snowballed since then. And now it's a global competition of over 200 cities in, I think it's 32 or more countries. When you say a competition, what do you mean by that?

We're all competing with each other? So in years past, it has been a competition, yes. And this year, because of coronavirus with many of us in our homes, we have turned it into more of a collaboration, a celebration of nature in urban spaces, what can we all find together as opposed to competing with each other? Tell us a bit about how, once we collect all this data, and I mean we, I mean you, how might this data be used?

Yeah, so the platform that most of the cities are using is called I-Naturalist, and it's an open-source data repository. I call it like Facebook for Nature Nerds, and all of the data gets put into that platform. photographs or sounds can be uploaded. And then that is evidence for what is in the city. And we have a biological record, just like a record in a museum collection that has a specimen, this has a photographic piece of evidence instead. And we have a date, a location, we know who collected it, and what that species was. Yeah, I have an I naturalist app on my phone. I use it. But do I have to

send my photo to some place in particular? So no, you don't. The great thing about Inaturalist is the projects that we have created for the City Nature Challenge automatically aggregate within the boundary. So for L.A., it's the entire county of Los Angeles, and any picture or observations submitted during that time automatically goes into the City Nature Challenge. I'm I reflato, and this is Science Friday from WNYC Studios. Can I take a picture of my dog? and send it in? Well, some people do do that, but we really like it if it's wild creatures, wild plants and animals. So domesticated animals like cats and dogs or like a rabbit that you might be having as a pet are not necessarily encouraged.

Animals in zoos not encouraged. And plants in potted areas like in your house or in your backyard, cultivated plants are also really not necessarily what we're looking for. we're looking for those wild species. So a weed growing in the crack of a sidewalk, something that is grown there by itself without the aid of humans. So I guess you're going to be a little bit limited in searching through your locale because you're going to be limited to your backyard or the cracks in your driveway or the sidewalk this year. It's hard.

It's hard for everyone. And I really feel the difficulty of it personally and from all of our organizers that we've been talking with around the world. So we understand that it's really difficult and we understand that people aren't going to be making observations in the same way. But I'm living with my parents and I went into their garage and I took some pictures of some brown widow spider egg cases. I have been in my parents' backyard and taken pictures of little flies landing on leaves. Wow, yeah, yeah, yeah, yeah. Give us the dates. How long is this collection happening?

So it starts at basically 12 a.m. on April 24th and goes through 11.59 p.m. on the 27th. And so any picture, any observation made within that time period counts. You can upload them right then and there. Or if you are really like taking a lot of pictures, you can upload them over the next week. And we announced the results on May 4th. And all you need is one little app on your set. Exactly. And if you want to learn more, let me tell our list. about the City Nature Challenge. We've got a SciFrii live stream coming up. You can ask a Leela and her co-founder, Alison Young, questions you might have about the event. And that event is on Tuesday, April 21st at 4 p.m. Eastern Time. You can find out more about the City Nature Challenge and other fun citizen science projects at ScienceFriday.com slash citizen science.

Thank you for coming on the show, Leela, and talking about it. Thank you so much for having me, Ira. Leila Higgins is one of the founders of the City Nature Challenge, based at the Natural History Museum of L.A. County in Los Angeles. After the break, we'll take a trip to a forest down in Antarctica, a forest. What plants and animals were roaming 90 million years ago in a much warmer South Pole could be a dinosaur or two. This is Science Friday. I'm Ira Flato. On this planet, if you're looking for a cold place, check out Antarctica, the coldest place on Earth. But listen to this.

At one time, we're talking 90 million years ago, there was a temperate rainforest in Antarctica. So instead of snow caps, there were swamplands. A team of scientists wanted to know just how warm the temperatures were at the southernmost continent. So they went there and drilled down deep into the mudstone. and what they found, their results were published in the journal Nature. My next guest is here to fill us in on that story. Johann Kluggis is an author on that study. He's also a marine geologist and a research scientist at the Alfred Vegner Institute in Bremerhaven, Germany.

Welcome to Science Friday. Yeah, thanks for having me. Let's talk about this core. So you drilled the core down, and what did you see in the core? Yeah, that was pretty exciting for us because it was also a totally, unexpected. First, we had to go through 1,000 meters, about 3,000 feet water, and then drilled 30 meters into the sediment. And all of a sudden, in about 27 meters depth, we got into something very different and something that we didn't expect at all. The first thing we realized was that it had

a completely different color that we have never seen before. And we, all of us from the science crew. We went to Antarctica already several times and we looked at hundreds of different cores and that was definitely very unusual, very dark material, very fine-grained and there were some dark spots in there that we couldn't really explain at first. But yeah, so that was the first impression, very different from all of what we saw before. So did you then realize you had drilled into a temperate rainforest? No, not at that time. I mean, at first it was not really tropical. It was a temperate rainforest, so not that extreme. So a temperate environment, but still warmer than we have right now, let's say, in Germany.

And about the temperature New York City experiences today. But we didn't know that, of course not, because we had to apply a ton of different analysis to really dig into what we found. So that was very exciting and that took another two and a half years until we were there. And if you see photos of the South Pole today, all you see is the white ice. So how come there was a rainforest there where it's not today? That's an interesting question. But you have to realize before. So the latitude we drilled, today is at 73, 74 degrees south.

And back then it was even further south. So at 82 degrees south only 900 kilometers away from the south pole. So that was for us, that was crazy to realize. And then we had the same question, like, how was that possible? And therefore, we wanted to first apply it all these different methods, but then wanted to know what kind of climate conditions and climate dynamics were necessary to maintain such an environment that far south. And that was the time where we decided to get some paleo climate modelers involved. And they really were able to tell us how the Earth at that time must have looked like.

And what did they tell you? What was the climate like down there? So much more extreme than we expected so far. I mean, we knew that the late Cretaceous, and especially the time around 90 million years, was the warmest phase of the late Cretaceous, and also one of the warmest phases in the past 140 million years of the planet. But we didn't really have geological records or geological evidence from that far south.

And so we now knew that we had a very diverse environment with a lot of different plant species and very warm temperatures all year long. And so we put that as a target value for that model. So what is necessary in the climate system to meet these environmental conditions? And it was crazy because we needed at least 1,120 to 1,680 ppm CO2 in the atmosphere. So to put that in perspective, today we have around 410, 420 ppm. So several times more, but not only that, it was also in order to meet that, in order to be able to simulate that in the model, we needed to assume that Antarctica was

completely covered in vegetation and no ice was present at the time, so no ice sheets. And so where was the continent itself at that point to give you such a warmer climate? It was interestingly more or less in the same position that is today. And as I just said, it was for this particular location we talk about, so where we took the core, it was even further south. So if we go back 90 million years ago, we have an interesting time. So we have the phase where Gonvana was breaking up. So Gonvana is the last big supercontinent.

90 million years ago, Zelandia, so the submerged continent of Zilandia, only New Zealand now is looking out the water. But Zelandia was just about to break up from West Antarctica. But Zelandia was drifting or moving much faster than West Antarctica did. So West Antarctica basically remained in place, more or less, and Zilandia was drifting away very quickly. And now it's several thousands of kilometers away from West Antarctica. But West Antarctica itself remained pretty stable and remained south. So, yeah, 90 million years ago, it was even further.

south, so even closer to the south pole where we drilled. That is amazing. So what you're saying is because we basically had the greenhouse effect going on there with all that CO2 in the atmosphere. We knew it was one of the last big greenhouse climates on the planet. We had several of those, but the late Cretaceous greenhouse climate was the most extreme. And we knew that before. But what we now revealed is that it was even extreme.

than we saw it because the records we had so far, so geological records with really solid evidence, where from about, let's say, maybe 70 degrees south, so 1,400 kilometers further north. And now we are much further south. So what we brought up from the current sea floor is by far the southernmost Cretaceous record available on the planet so far. and therefore it's a unique insight into the polar environment at that time. And when I say polar environment, it really means very close to the South Pole. And that was not available before.

All right. Well, now that you've wedded my appetite, you have to tell me what you actually did see. What did you see in those core samples? What kind of trees and pollen and things like that? Yeah, that was exciting because I told you when we first saw the material on board, And some colleagues wanted to look at it immediately. So that means splitting the core. But some of us said, no, no, we definitely won't do that because we already knew that something very special is inside them.

And you have to realize it only has a diameter of six centimeters. And it was three meters long, this late Cretaceous section. So it's a very valuable material. And therefore, we decided we bring it back home. And then the first thing we did was CT scanning. So a 3D CT scanner, and that was the first time we really saw what's going on in that core. So when we first looked at this 3D data, we saw this pristine and very well-preserved network of fossil roots. And these roots go down to the bottom of the core, and it's within a matrix of very fine-grained material.

so silty clayy material and this material was full of pollen and spores and in situ pollen and spores so no, we're working nothing. And that we already found out on board that this is a completely entirely terrestrial assemblage of pollen and spores and also the material itself

must have been completely deposited in a terrestrial environment. And so all the evidence that came together then, also the geochemical information and the sedimentological information, all pointed into the same direction that we discovered a temperate rainforest environment

at 82 degrees south. So that was just amazing. That is amazing. Now, you know, of course, when we talk about going back 90 million years, we know, our listeners know that that's at the time when dinosaurs roam the planet. Could there have been dinosaurs there too?

Yeah, it's very likely that there were. I mean, I just told you how little materials, we got six centimeter diameter and three meters long. So we have no direct evidence of dinosaurs or any faunal life in there, but from records further north. So for example, from an outcrop on the Sema Island, which is on the Antarctic Peninsula, we have evidence for dinosaurs.

For that particular location at 70 degrees south back then, we have evidence for that. And because it's a similar environment, it's very likely that they were also there. So it would be much weirder if no dinosaurs or insects or flying dinosaurs were present at the time. You talk about how much CO2 was in the atmosphere causing global warming at that point there. Is there a lesson for us? You study the ice sheets.

Is there a lesson for us here today? Yeah, there's definitely a lesson because so right now climate science and also paleo climate science is lacking, so the understanding about these greenhouse climates in general. And so the only chance we have is to go back in time and get really empirical evidence about the climate dynamics during these greenhouse climates. Because right now we are on a good way to drift again into climate states that could be pretty similar and could drift into something like a greenhouse climate. And therefore, we need to understand climate dynamics in these extreme times.

So we call them end member climates because these are really the most extreme climates we had on the planet so far. But climate models really have struggled to simulate the global climate dynamics during these times. And yeah, especially because we don't really have, or so far didn't have records from polar regions for this and South Pole regions for this time. frame. And now we know it was probably much more extreme. And the temperature gradient between subtropical and tropical regions and the polar regions was much shallower than we knew before. And that has profound consequences for climate dynamics during that time. And we need to understand that because, as I said, climate models, if you force them with these high temperatures in polar regions, they simulate way too warm temperatures for tropical or subtropical regions,

are unrealistically high. So therefore, there must be a lot of bugs in these climate models, and these have to be evaluated and assessed in the future. And you think by drilling into the ice core, you can help fix those models? Yeah, because we can calibrate the models with that. So because we can tell the modelers how it was, which kind of values they have to target in their models. If this is not possible, at the same time,

for tropical, subtropical regions where we have a lot of records from this time frame and now these new records from polar regions, then it's not a good model. And therefore, it has to be re-evaluated and much more work needs to be done in order to meet that in a reliable way.

I'm Ira Plato and this is Science Friday from WNYC Studios. What can the core samples tell us about the big ice sheets there now, the West and the East, Antarctic ice sheets. You study the ice sheets, I know. Yeah, we are pretty lucky right now to have them. You have to imagine these huge ice sheets that we have right now. So the East and Arctic, West Antarctic and Antarctic Peninsula ice sheets, so the four big ones, they act as gigantic

mirrors for the radiation that comes from space and gets reflected back to space. So therefore, this radiation is not really acting as a, as a, warming on the planet. So therefore, they have a huge effect for us right now to cool down the planet. And so the Antarctic ice sheet, which is by far the largest one on the planet, acts like a huge refrigerator for the planet right now. And therefore, they have a profound effect on climate right now. But we have to say that not only atmospheric temperatures affect, those huge ice sheets, especially in Antarctica right now, and this is another topic where I intensively work on, is that warm ocean waters and not surface waters, but deep ocean waters,

that they spill onto continental shelves in Antarctica and melt the ice from below, so from underneath. And that was a process that was not really known 20, 25 years ago. And this in combination, so a warming atmosphere in the future and also warming deep ocean waters. That will be a combination that won't be good for the future. You've been there many times doing research in Antarctica. I was there once many years ago. It is a gorgeous, gorgeous place, right? What's it like for you when you go back down? And if you go back down, if and when, and you're doing more core samples, what's the next thing for you? Yeah, so I've been there now four times. It's just such a fascinating environment.

It's so huge and so beautiful and so quiet that you realize, okay, this is the planet without humans. I mean, besides the ones that are on the ship with you together, but you don't see anything in any way affected by human behavior. So that's one very amazing thing. And when I work in Antarctica, and I mean, we have long days on the ship. We work basically 24 hours in shifts. And once a day, at least, I need to go. up on the upper deck and just realize how fascinating and surreal this environment around me is. And the next steps for us now is, yeah, it's really to understand what the West Antarctic

Ice Sheet in particular, but also parts of the East Sand Arctic Ice Sheet, can tell us so that the past processes of these environments can tell us about the future development of the ice sheet. So getting to know most detail the history of those very vulnerable parts of the ice sheet in the geological past, how this can tell us about its future behavior. And I think this is the main driver for us right now to work there. Well, we wish you great success and great luck, Dr. Klages. Thank you very much. Johann Klagas is a marine geologist and research scientist at the Alfred Veginer Institute in Brimrahaven, Germany. If you missed any part of the program and you would like to hear it again, subscribe to our podcasts or ask your smart speakers to play Science Friday.

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