The Origins Podcast with Lawrence Krauss - Daniel P. Schrag

Episode Date: July 23, 2019

In this episode, Lawrence joins environmental scientist Dan Schrag at Harvard University to discuss Earth history, energy policies, and what we can expect from a future affected by climate change.  See the exclusive, full HD videos of all episodes at www.patreon.com/originspodcast immediately upon their release. Twitter: @TheOriginsPod Instagram: @TheOriginsPod Facebook: @TheOriginsPod Website: https://theoriginspodcast.com Get full access to Critical Mass at lawrencekrauss.substack.com/subscribe

Hello, and welcome to the Origins podcast. I'm your host, Lawrence Krause. In this episode, we'll talk to the geophysicist Dan Shrag. I first learned about Dan as he gained national prominence for his groundbreaking work on paleo climate, particularly the striking snowball earth hypothesis, now widely accepted that the earth froze over completely on several occasions between 600 and 800 million years ago.

Since then, he's become a leading figure studying current climate change as well as energy policy and technology. He directs Harvard's Center for the Environment and the Program on Science and Technology and Public Policy at Harvard's Kennedy School. Dan presents bold ideas of what we need to do to address the inevitability of climate change as well as mediate it. Our in-depth discussion will inform anyone interested in the complex political and scientific challenges we need to deal with to move beyond our current crisis.

to a more sustainable world. Patreon subscribers can find the full video of all of our programs as soon as are released at patreon.com slash origins podcast. I hope you enjoy the show. Well, Dan, it's good to be with you again, as always, here in your layer, as it turns out. There are so many things I want to talk to you about. Every time I'm with you, I learn something useful about the climate and the earth. Let me ask you, I want to start with your origin.

and so I want to start, what was it about geophysics, geoscience that got you, that made you to do that rather than something else? You know, it actually took a long time to answer that question for myself. Yeah, good. Well, you can take as long as you want to answer it here, too. I was an undergraduate at Yale, and I'd always done science as a kid. In high school, I actually spent four summers working in a laboratory of a neuroendocrinologist. my first paper is written about the angiotensin and the hypothalamus of the Brattleboro rat.

So doing biomedical research, and I think everybody expected me to go to medical school. And I think that was just about the time where all my hormones said that I had to rebel. And so I did something different. Oh, okay. And I think I had this idea that I would become a physicist. And I took a course my freshman year at Yale that was above the course that was normally offered for physics concentrators at Yale. This was a course for people with extreme physics and math preparation, and I didn't have it. And it was a very good life lesson that there are

just a handful of people who are always going to be much better and much smarter than you. At the same time, I had taken a political science course on political theory and a modern philosophy course from Harry Frankfurt, and was totally inspired. But I couldn't quite give up science. And the master of my college where I was living said to me, he was a physics professor, one of your old colleagues, Frank Firk. Oh, yes, I remember. And he was a lovely man. I don't know if he was a good physicist, but he was a lovely man. And he said to me, you know, you should really try geophysics.

But I kind of thought about it in terms of political science and resources. I ended up being a double major in political science and geology and geophysics. It would not be perfect. Yeah, it turned out I didn't put much effort into the geology and geophysics side. I put a lot of effort into the political theory side and loved it. But when it was time to go to graduate school, I couldn't quite imagine becoming a philosopher. I don't know why. Honestly, it was, I think, because I'd never imagined being an academic.

But in the end, I went to Berkeley to study economic geology. and while I was there, luckily ended up meeting somebody switching advisors and working on what I would call really basic fundamental questions. These are about Earth science, about how the Earth works,

that have almost no relevance to people whatsoever. What I was studying was how alteration of the ocean crust, a few kilometers below the ocean floor, how that changes the chemistry of the rocks and how we can measure it by doing some diffusion reaction models. So it was basically modeling fluid rock interaction in basalts.

Pretty obscure. What I discovered was that the changes in the chemistry of the sediments on top was actually pretty significant and that chemistry was actually used to reconstruct ancient climate. So my entree into climate

was actually a very backer It wasn't that I went to graduate school to study climate change or to study the environment. That was the furthest thing from my mind. But, you know, it's kind of, I don't know whether poetic or useful or just serendipitous, that you're, I've always thought of you as someone, maybe because of a kindred spirit, thinking of the physical mechanisms and the actual physics behind, not just climate, but the way the Earth system works. And so that physics background, or at least that scientific background,

has been incredibly important in my mind in what you've done. And in your ability, therefore, to not just communicate to the public, but to be able to do good science associated with climate change. So I think there's two aspects. Part of the reason climate change is so interesting scientifically is that it's actually an incredibly complicated and fascinating scientific experiment in the context of Earth history. Yeah, yeah.

And so the science itself is really interesting, even if it had no societal implication. But it does. But it actually does, and then that makes it a whole other aspect. It's interesting because also in your own life, this beautiful marriage between science and politics has carried out, as we'll talk about. And I want to talk about science and public policy, which you've been involved in. But let's go, one of the big arguments that's given about climate change is, well, the climate always changes. One of the big denial arguments is climate changes and big deal. So the climate's changing now.

It's always changed. And your work over much of your work has involved the historical understanding of climate change, particularly over the history of the Earth, not just over the last 50 years. And you first became known to me with the remarkable work on Snowball Earth. Just to give a sense of perspective of where we're going to go when we talk about today's climate, Why don't you talk about the long-term climate changes and the things that have happened in the earth, including Snowball Earth?

So what's actually interesting is that the Earth has experienced such an incredible array of different climate states over its history. And our knowledge of that history essentially gets worse and worse as we go backward in time. So, you know, for the last 150 years, or so, we actually have instruments.

There are a handful of instrumental records that go further back, but it's, you know, it gets pretty bad before about 150 years ago. Before that, we have tree rings and some ice cores and some sediment cores, and they can give us pretty high resolution records back over the last few thousand years. And then when we go back over the last few hundred thousand years, we actually have sediment cores from all over the world's oceans that give us, you know, century or multi-century resolution going back millions of years, and we can actually take that back, you know, over the last 65 million years. But as you start pushing it further back, a couple of things happen. The records themselves degrade because rocks get buried, they alter, they chemically alter. That was actually the topic of my dissertation. But in addition, essentially, you're looking for a big signal. So when I moved, I taught at Princeton for three years after I left Berkeley and was working really

on two timescales. I was working on sort of stuff that happened over the last 60 million years or so. And then also looking at corals. Corals grow like tree rings. They put down about a centimeter a year of growth, and we can use them to get records of El Nino for the last few centuries or things like that. So I was reconstructing choral records with El Nino, and then reconstructing El Nino with coral records and then working further back in time, but thought that basically prior to 50 or 60 million years ago, it was hopeless. And then I moved to Harvard and started this friendship with a guy named Paul Hoffman. And Paul was a geologist who spent most of his career studying the Precambrian.

But he was an unusual Precambrian geologist. And just for some listeners, the Precambion is some six, seven, 100 million years ago? Yeah, it's before about 540 million years ago. And it is an interesting time period because it's essentially most of Earth history. Yeah. The Earth's 4.5 billion years old. So the first 4 billion years essentially is the pre-Cambrian.

And it is the time. So the thing that marks the Cambrian is the appearance of lots of trace fossils. It turns out, as we look at the record, there are some fossils before the, the, you Cambrian, many of them. But at the time, this was an explosion where you saw all sorts of bioturbation and all sorts of an explosion in the fossil record. In fact, if I'm right, of course, in many people, because that's when fossils first were seen, for many people that early on, that was the origination of life.

They didn't realize that life had gone much earlier than that. That's right. That's right. And in fact, some of the classic work by Harold Uri, the great chemist. at the University of Chicago, early on when he was doing early work on carbon isotopes and oxygen-stable isotopes, he actually wrote in a paper that the carbon isotopic

composition of organic carbon could test whether there was life back through geologic time because of the fractionation from photosynthesis. So, I mean, amazing history there. Yeah, yeah. And I think at the time, the paleo-climate community ignored frankly, most of the Phanerozoic, which is the last 540 million years, they really thought back to the Cretaceous, but not much before that, which is sort of the last 60 to 100 million years.

Okay. When I first got up and gave a talk on the work that Paul Hoffman and I did on the snowball earth, these were two glaciersions that occurred in the Neo-Prederozoic, which was a period from about 750 million years ago to about 600 million years ago. That's when the glaciersions occurred. And just to make it clear by glacier, we're not talking about small-scale glaciation. We're talking about a snowball. That's right. And people said, how could you possibly work on this? We don't know anything about the precambrian.

This is, the rocks are so altered. How do you say anything? And the answer is it's a signal to noise issue. When the environmental signal is so huge, it turns out you can see it above all of the complications. And it'll come back because I want to talk about the Earth and other planets. but the fact that the Earth, which is habitable, certainly, apparently, at this point, was essentially frozen over in its history.

I mean, it was just shocked. I know it shocked me. I think it was very controversial. But that's going to be relevant to understanding the history and origin and nature of life in other planets in the solar system. Well, I think, you know, as you know, science is about storytelling.

Yeah, yeah. We scientists sometimes don't like to admit. that. Yeah. But it's true. Yeah. Good science is a good story. I've said the greatest story.

But anyway. That's right. And I think there is, in all good stories, there are only a handful of themes. And one of the classical themes is catastrophe and redemption. Yes. Right? And that happens again and again. Yeah.

And I think, you know, the mass extinctions, whether it's the Promatriassic extinction or the Cretaceous tertiary extinction. So the meteorite hits, all sorts of things die. the dinosaurs get wiped out, but the mammals arise and look, here we are, right? What a great story of catastrophe and redemption. Similarly, it turns out that that may actually be the story of the snowball earth. Yes. That we're doing work right now that links those snowball glacations both that time and then

about 2 billion years earlier, about 2.4 billion years ago, there was another pair of snowball glaciers. Oh. And both of these coincidentally occur right at the time when oxygen jumps up in the atmosphere. The overall pattern in Earth history was for the first two billion years or so. There was essentially no oxygen in the atmosphere. Which, by the way, I mean, most people don't realize. Well, of course, for a long time, Yuri and other, I mean, people assumed the primeval atmosphere was similar to what it is now or in many ways.

And of course, what people don't realize is that it's darn lucky for life on Earth that there wasn't any oxygen early on because oxygen would have essentially, I mean, life is slow burning and oxygen would have basically taken all the organic materials and oxidize them, which is what life sort of does. Well, there's an interesting thing about how much oxygen is too much oxygen. Yeah, yeah. But, yeah, so we think that, you know, there was about, I mean, 10 to the minus 6, 10 to the minus 7 of present atmospheric levels of oxygen.

in the early days. So this happened for the first couple billion years. So origin of life happens in that environment. A lot of people studying the origin of life don't, they sometimes forget that it's truly an anoxic environment. It's very different, possibly hydrogen-rich. Then around 2.4 billion years ago, there's very clear evidence of a jump in atmospheric oxygen.

It's called the Great Oxidation event. Yes. And the timing of it is almost exactly, coincident, we think perhaps exactly coincident, with this global glaciation, one of the snowballs. And then again, around 600 million

years ago, we think oxygen went from something like 1% of current level. So after the great oxidation event, oxygen is higher, but it's not like modern. It's maybe 1% of modern. Okay. So, essentially, everything was still unicellular,

but you started to have algae. Instead of just prokaryotes, you had prokaryotes, you had prokaryotes and eukaryotes. So what that means is cells with mitocondrio, later on with chloroplasts. So it's more like our cells. But they're still single cells. What happens, it's possible that multicellular animals evolved sometime in this period, in the preterozoic.

But if they did, they were really tiny. They were like multicellular little amoeba things. They were tiny little guys. And the reason is because oxygen's only 1%. If oxygen is very low, you can't get big because you have a diffusion problem. Well, yeah, and I mean, to make it even clearer, I think of it in terms of physics, as I, it's not surprising,

but oxygen allows living systems ultimately to get about 40 times more energy than they would in the case of sort of photosynthesis or in a... Yeah, I mean, the key reaction there is actually if you try to eat food, if you're a heterotrofe, and you try to eat food, so you take organic carbon, and you try to oxidize it with something like iron or with sulfate or something like that,

it turns out you get about 20% of the energy that you would get if you used oxygen. Yeah, the point is that, I mean... Much lower energy yield. Yeah, much lower energy yield. I mean, that's what life is for people. It's more machines. But there's plenty of anaerobic heterobic,

heterotrophes that do just fine. Yeah. The point is that that if you try to make a multicellular animal in low oxygen, so then oxygen jumps up 1%. That's plenty for using oxygen now. Yeah, yeah. Right?

So a lot of the zooplankton and single-celled organisms would do just fine in that 1% of oxygen. But when you try to get big, imagine you're the cell in the middle of a cluster of cells, you don't get any oxygen, right? And the way we solve that in our big bodies today is we have a circulatory system. But it's hard to evolve a circulatory system before

you get big. There's a chicken egg problem there. So what we think happened was around 600 million years ago, oxygen went from 1% to something within a factor of a few of modern level. So it went up by a factor of 20, 30, 40, something like that. And that allowed everything to get big. And that's when multicellular animals happened. So in some ways, the interesting part of our work on oxygen and the snowball is that it was the glaciation, this environmental catastrophe that actually changed the environment. We have a mechanism where the glaciation actually allows for a jump in oxygen levels.

Is it simple to describe? Well, it's not that simple, but essentially what we found is that when you think about, when you think about atmospheric oxygen, you have to worry about electrons. It turns out that you either, you're talking about oxidation and reduction. And there are really only a few geochemical cycles that matter. You have to worry about iron and you have to worry about sulfur and you have to worry about carbon. And when you couple those, what we found was that this very simple model we put together actually showed three stable equilibrium states. A very low one, like what the Archaean was, essentially

no oxygen, a medium one that was about 1% of current levels, and then a kind of modern level. This is stable when it's glaciated. No, no, no. Okay, before. The point is that each of, if you were in one of these states, the geochemistry, there are actually some very strong negative feedbacks that keep you in that state. You won't change, but you need something dramatic to make it change. But it turns out you need a kick to get you from one state to the other. And we think the snowball was that kick. So if you actually, so if I were to give you my version of the history or the evolution of the earth and the evolution of life, it's first of all not inevitable that we would end up here. Yeah. It's very important because some people think that there's sort of this,

you know, direction. Yeah. And the answer is, you know what, were it not for those snowball glaciation, we could still be in the Archaean with prokaryotic cells with essentially no oxygen. Yeah, it wasn't written. I mean, that's one of the lessons of all, I mean, from my experience of the whole universe, is a series of remarkable accidents.

There's no way that we were destined to be here. It's a very fortuitous. It makes the appearance of multicellular animals and ultimately humans even more extraordinary. Yeah. Because you realize that these glacations didn't just happen to Earth history. They aren't just an interesting mass extinction.

They actually completely shaped the evolution by actually changing the atmospheric conditions with respect to atmospheric oxygen, which changed everything, allowed life to get there. And I think that's what, I mean, in giving historical perspective, because we're getting into the present ultimately, the point is that we humans who live for such a short time

in a cosmic sense or even a geological sense, think of things as having always been this way, and it's natural to assume they've always been that way, but that the earth is very dynamic, the climate is very dynamic, and the development of life and living systems depends crucially on sometimes subtle changes, and that's going to obviously be relevant

when we think of our own future. And of course, the reason that that's not so intuitive is that these generally have taken place over geological time, and we're in a situation now where there are changes that are happening on a much faster scale that are unprecedented in the history of the earth. But it's interesting to see how dramatic the changes have been in the nature of life and the atmosphere and the chemistry of what's going on on Earth. Yeah, that's exactly right.

I mean, at the same time, I think let's get into what's happening today and talk about the historical context for it. You're right, it is unprecedented, and it's particularly unprecedented in the pace, right? It's the rate of change that's unusual. On the other hand, a geologic perspective on this is healthy because the Earth is going to be fine. Yeah, the Earth will be fine, exactly. And in fact, life, you know, I remember writing, when I was first learning, actually, from one of your colleagues, Annie Knoll, I was learning enough about to write in one of my books about the history of, well,

oxygen on Earth, and I was just learning. and it struck me. I think it's a characteristic generally that, of course, from a natural selection or evolutionary perspective, catastrophes open up a whole new window. So life, in some ways, in the long run, life loves catastrophes.

So catastrophe and redemption is this theme, right? And you keep coming back to it, and it's fascinating. I had a conference a few years ago gathering a bunch of conservation biologists, people who study the science of conservation. It's a little bit of a funny field, but it's a very important thing today, especially. How do you actually conserve species, for example?

And a lot of conservation biologists focus on species. And the reason I was gathering them was because I was trying to be a little provocative. What I wanted to do was challenge them a little to think about the timescale of climate change. One of the things that you understand or that we understand from studying the geologic past is that the timescale of climate change, you know, most of the IPCC studies and the UN stuff, People look at 2100 or 2050. Yeah, yeah, yeah. They might go out to 2150.

Yeah, yeah, right? But remember that, you know, of the atmospheric CO2, so when we burn fossil fuels, about 60% of the CO2 stays in the air, about 40% goes into the ocean and the land, that's 60% that goes into the air, half of that is still going to be there a thousand years from now.

That's a vital importance. I think that if it's one thing people should understand. It's really important. people don't think about it this way, but nuclear waste, high-level nuclear waste, in a thousand years, about 1% of the radioactivity is left, because most of it has short half-life. Yeah, yeah. Right? So, that's what makes it so nasty.

Yeah, exactly. That's why this stuff you worry about is this stuff that is short half-lives. Right. So, a thousand years from now, nuclear waste, 1%. Yeah. CO2? 50% in a thousand years. And probably about a third of it will still be here 20,000.

thousand years from now. So the timescales are really long. We are changing the earth, not just for a few generations, but for tens of thousands of generations of humans, if humans are so lucky to stay on this earth for that long. So that's, you know, hard to get your head around. Absolutely. And it'll become relevant. What many people say is, well, you know, maybe this is a problem, but we have economic problems, we have other problems. Well, let's not worry about it now. Let's worry about it in 50 years. And the problem is if you keep dumping it in there,

dealing within 50 years becomes so much harder than now. So let's come back to that. Because this conference was really interesting, gathering these conservation biologists. What I wanted to do was ask them, okay, so climate change, you're not just trying to save species from extinction. You know, conservation groups,

you know, World Wildlife Fund. Yeah. many of the other NGOs that do species conservation and biodiversity protection. You understand this is a multi-billion dollar a year effort. This is not small. Yeah, yeah. And I sort of felt like, you know, they're trying to save species from extinction. And, you know, if you think about this, you know, are you really trying to save species from extinction today?

So they go extinct a few hundred years from now? Or are you actually really trying to put up? preserve biodiversity. And if you actually take conservation seriously, in my view, in the context of the time scale of climate change, you should maybe think things differently. You know, maybe instead of worrying about this species of frog and this species of frog and this species of frog, you might say, you know what, I want to make sure we have frogs. Yeah.

Right? You know, I'm not saying you that the efforts that these are great organizations, they do a lot of good work. And I'm not trying to belittle what they do at all. I'm just saying, I think we actually need to step back and think about what we're doing and question, are there additional things we might be doing in this broader context of the timescale of this problem? And a given, and this is one of the things I really have learned in my time with you that is relevant, is that we can't stop what's already started. And we have to start thinking about how we deal with it. And it's not a matter of giving up. It's not a matter of saying let's throw up our hands and just, you know, keep

driving, you know, big cars and not worrying about that. But we have to recognize that these things are happening and have happened. And we've put in, you know, what it is, or 50 gigatons of carbon into the atmosphere. 500, yeah. And over per year, maybe. And that's there, that's there, and it's going to have an effect. And there are things we're going to have to do with like it or not. That's right. So the interesting. response of these biologists was fascinating. Many of them said, I don't care about these timescales because all the things we study are going to be gone in the next 50 years. It was a very, I mean, I thought, I thought, I thought I can be dark sometimes.

These conservation biologists really had a dark view of the world. But what was the fascinating was my friend Doug Irwin. Doug is a paleontologist at the Smithsonian and is a brilliant scientist. And Doug said, you know, what are we trying to save here? Are we trying to save species? Are we trying to save? But he said from a geological perspective, what I had said was, I would love to try to avoid this becoming like the Cretaceous tertiary extinction or the Permotriassic extinction.

You know, people talk about the sixth extinction. I was just going to say people talk about the sixth extinction. I don't think it's true yet. I think it's slight hyperbole. But there's no doubt that species are disappearing at a much faster rate. They absolutely are. Humans have been, since throughout their history,

we've been done a very good job effectively at causing extinction. But remember that like at the Prometriassic, we lost like 90%. Oh, no, no, I know. So we're not there yet. Yeah, yeah. But Doug said, you know what?

Look what happened after the Prometriac. Like, everything recovered. I was just good, well, I've often wondered that if, especially if we got rid of humans, that there be an explosion of new. So what's interesting is, and I realized, you know,

applying sort of human values and human morality to geologic time and evolution is a very tricky thing. Sure. Because things, you know, catastrophe and redemption, you know, we are programmed to think catastrophe is catastrophic. It's terrible. Especially if it's us.

Right. And it's more complicated than that. Yeah, yeah. No, there's no doubt that we're changing the earth, and there's a lot of species that are going to be extinct, but it's probably unfair to suggest that that won't up, it will be true that that will open up evolution. new species that wouldn't have been able to survive before.

Now, that's often a very bad thing because we often find in the United States and other places that predatory species that are dangerous are now viable that weren't before, and then we're going to have to live with that. But there's no doubt we're opening up, even as we change the environment, we're opening up evolutionary, new evolutionary niches somewhere. That's right. So let's get back to the question of the sort of, historical context for what we're doing today. Yeah, it's good. Because I think it's important to understand,

you know, we actually know the historical climate for the last several million years really well. Exactly. And I think that's an important thing too because people say, well, the question is always, well, people weren't around. How do you know it? And the point is there's lots of evidence. But I want to, I think it's really important if we're really going to have a serious and intelligent discussion of what climate change today to have that historical context. So I'm glad we've discussed it anyway. So, so, you know, we, we, for the last couple million years, we had these periodic ice ages.

And we know a lot about it. They were driven by subtle changes in the Earth's orbit around the sun, changes in how tilted the Earth was or its procession around the sun. And the interaction with essentially two main factors. Ice sheets, which can amplify climate signals, because when ice grows, it reflects more sunlight back to space and has a powerful positive feedback. That's part of the snowballed earth phenomenon, too.

Yeah, sure. And also carbon dioxide. So the carbon cycle is another positive feedback. And these things seem to have worked together to keep us in this relatively stable pattern of, you know, fluctuation between glacial maxima and glacial minima or what we call interglacials. Let me interrupt for a second, just as when you talk about the reflecting sunlight in the space and carbon cycle, what's really important, it seems to me, in talking about this to members of the public, and sometimes politicians, is that this isn't always rocket science.

The details are very complicated models, but the basic physics of energy flow is pretty straightforward. That's exactly right. And what's surprising is that it works. I mean, maybe not surprising, but when you see that these basic physics predictions work, there's a good reason to trust them. Yeah, I mean, the basic idea of climate change has been around for 100 years.

Yeah, I mean, it's just the energy in, energy out. It's not much different. I mean, that's not to minimize the incredible complexity of clouds and the way and where on Earth temperature will change and how it impacts on sea level and all that. But the basic physics of energy out of which carbon dioxide is apart is not rocket science. No, absolutely not. And indeed, you know, people sometimes forget our neighboring planet Venus, right, which is very similar to the Earth in size and is about 460 degrees. Celsius on its surface. Yeah, yeah, exactly.

Super hot. Why? It turns out most people think because it's closer to the sun. And it's true, Venus gets about twice as much solar energy as the Earth does, because it is closer to the sun. But because it's so bright and reflective on the surface, if Venus had the same atmosphere as the Earth,

it would be substantially colder than the Earth, which is interesting. It is interesting. The reason Venus is so hot, you know, it's 460 Celsius. It's pretty hot. Incredible hot. It's because it has an atmosphere almost 100 times thicker than the Earth, and 97% of that atmosphere is carbon dioxide.

Yeah, okay. So, you know, the greenhouse effect as a phenomenon is really not in question. And it was relevant at the early history of the Earth. The Earth would have been, I mean, the sun has been getting brighter. It was 15% less bright in the early history of the Earth. And so we should have been frozen except the carbon. And then there was a greenhouse effect that preserved liquid water on the Earth in the early history of the Earth.

The carbon dioxide density was something like 10,000 times what it is now in the very earliest moments of the Earth or something? Probably not that thick, and there may have been some additional gases as well. But here's the, but the general idea is there's actually a remarkable chemical reaction. So there's a chemical reaction between carbon dioxide, water, which makes carbonic acid, and then rock. Yes. And that reaction, igneous rock, volcanic rock. And that reaction yields, a... Essentially, it's an acid-based reaction.

So carbonic acid is an acid, and it reacts with the igneous rock and basically makes calcium carbonate or chalk or limestone. It stores the carbon. And so essentially, that chemical reaction takes carbon dioxide out of the air and converts it to limestone on the ocean floor. Yes.

What's amazing about that, so that reaction, because that reaction is temperature dependent, that becomes a thermostat. So when the Earth gets too hot, that reaction speeds up, and CO2 is drawn down. And when that reaction goes too slowly,

volcanoes naturally trick. Now remember, volcanoes are only putting out about 1% of what we're burning from fossil fuels. So it's not like volcanoes are in danger. But they're doing it all the time, and the CO2 coming out of volcanoes is balanced by what is going back down is calcium carbonate.

It's this remarkable balancing. And so it's this incredible cycle. Until life evolved. Now, what we're doing to it is really extraordinary. Yeah. We are perturbing it by a factor of 100. Yeah, that's important.

I think that, you know, the Earth will take care of it, right? Again, these chemical weathering reactions, this reaction between water and rock and CO2 will happen. And it will take care of our problem. But on geological... But it will take about 100 to 200,000 years. Yeah, yeah, exactly. So it's just not fast enough.

Yeah. No, so I was going to say, people, when they hear about this natural thermal stuff, they say, the natural reaction be, why worry? look, the Earth's taken care of it, but we're changing things on a scale that the Earth can't adjust to. I think there's another aspect of global warming that, again, is relatively simple physics that people can understand. If you look at a pattern of global warming, what you see is that the Arctic's warmed a lot more than the rest of the world over the last hundred years, and also that the land has warmed about twice as much as the ocean. So, you know, overall, the world's warm by about one degree.

Over land, that number's almost two degrees. And it turns out there's a very simple reason for that. You know, when we plant tulip bulbs in the fall, you plant them a few inches down, and they're protected from the frost of the winter. Right? Since Lord Kelvin in the 19th century, he actually measured temperature down a mine shaft to study the diffusion through soil. So he did all of these amazing experiments. He was interested in the age of the earth from thermal conductivity.

Yeah, it's wonderful. That's what I always love about when I do physics, is that whatever question you have, someone has spent their life studying it, it's really kind of amazing. It's remarkable. But when you think about this problem, it means that the surface of the earth doesn't actually have a whole lot of ability to absorb heat. And the reason is not because it has low heat capacity,

Rock actually has a lot of heat capacity. It's that essentially rock is, you have to diffuse. You're conducting that heat through a solid, and that's fundamentally slow. That's why you can plant your tulip bulbs a few inches down, and they're protected from the winter freeze, right? Okay, so, but the ocean is different. The ocean mixes. The upper 100 meters mixes almost instantly because of the winds and the churning.

Deeper down, you have currents that mix it on slightly, longer time scales, but decades to centuries, now you're talking about, you know, the upper thousand meters of the ocean and the deepest ocean, the four or five thousand meters down is mixed over thousand year time scales. But what that means is if you had the planet completely land and you, and if we had no oceans at all, and we raise the carbon dioxide level in the atmosphere, like we've done by burning fossil fuels, the Earth's surface would heat up relatively quickly and achieve that equilibrium really quickly because there's not much ability to soak up heat.

We have a world that's covered with ocean, right? 70% of our surface is covered with ocean and it mixes. And so what you can think of this is do the experiment. You're adding carbon dioxide. The earth's trying to heat up, right? Energy's coming in, and the way you achieve that energy balance is by the surface heating up so that the radiation going out equals the radiation coming in.

Exactly. But the problem is the oceans are cold. Yeah. And it takes a while to heat up because they mix that heat downward. And so essentially 90% of the energy from the greenhouse effect that's being absorbed by the surface of the earth

is going into heating the oceans. Where do we see that? We actually see that in sea level rise. So thermal expansion of water. And so in some ways, sea level rise is global warming. Yeah. Because that's 90% of the ocean. the energy. You know, global warming is ocean warming. I want to slow, I want to decompress that

a little bit for people, because I think a lot of people think sea level rise comes just from simply melting of ice, you know, in Antarctica or Greenland. But the point is that the sea level rise we're seeing when water heats up, it expands. It's just simple. And so today it's about half, maybe a little less, 40% of the total sea level rise is due to thermal expansion. There is an important contribution from Greenland and from Antarctica. It turns out that over the next century, those are going to get much bigger. Thermal expansion will continue, but the melting of the ice sheets is what we have to worry about because they're the ones that can really add to the sea level rise.

But today, global warming, like, it's happening. And people too often use, like, surface temperatures to indicate global warming. You say, that's the tail. That's not the dog. The dog is the ocean. Yeah. Right? And if you want to see global warming, measure the temperature of the ocean.

What's incredible is that we actually have new technology now, you know, until 15 years ago, the way we measured the temperature of the ocean is we went out on ships. Yeah, sure. I remember that. Dropped oceanographers down on a wire and measured them. That's what physical oceanographers did. Yeah, yeah. Hank Stommel, the great physical oceanographer, who was at Woods Hole and at MIT,

Hank Stommel, I guess in the 50s, he said, oceanography is like trying to do weather forecasting with a handful of cars towing kites around on a moonless night with clouds so that you couldn't see into the medium. Wow. You know, that's essentially what oceanography was. 15 years ago, they started this program called Argo, where these floats, they actually are designed to sit at about 1,000 meters depth.

And every 10 days, they drop down to 2,000 meters, and then they slowly rise up to the surface, taking measurements every meter of temperature and salinity. And then when they get to the surface, they beam the data back to a satellite. And then they sink back down to 1,000 meters and wait another 10 days. We now, in a few years, we collected more data on the oceans than we had in the whole history of oceanography. How many of these things are out there? There are about 4,000 of them. And it's a huge international program.

The U.S. is the biggest contributor, but we're probably, we've certainly contributed much less than half. There are, I think, 60 nations that have contributed to this float program. It's nice to see a global effort for a global problem. It's always nice to see that.

It is transformed our understanding of the oceans. And it's allowed us to see that the oceans are indeed heating up. And that is, to me, the real proof of global warming. There's another dark side of this, though, which is that, it means that if we were to somehow magically freeze the level of CO2 tomorrow, not emit any more carbon dioxide from burning fossil fuels, which is not possible.

The ocean's probably got another thousand years of warming because the oceans are not in equilibrium, right? The oceans are cold. They're soaking up this heat. And they're going to still coke it up. And the carbon dioxide is still there. And yeah. So if you think about it, the land gets equilibrium pretty quickly, the oceans are lagging behind. And so we may have close to double the amount of warming we've already experienced already committed in the system. Yeah. Okay. Well, that's a very important thing. But there's two points I want to take for this. One is that, yeah, even if we stop things today, there are going to be effects we can change. And two, many people think climate change is all based on predictions and models in the future. But it's

happening now. It's based on data you can measure. And even if, you know, a senator brings a snowball into the Senate, the point is that, you know, you make measurements of the ocean that are unambiguous. It doesn't matter whether it's cold today in Boston. And, oh, my God, there's no global warming because it's we're having a cold winter. There are real measurements that show you exactly what's happening. Unambiguously, it's not model dependent, it's not consensus dependent, it's not politically dependent, it's happening. That's right. And the models we use, honestly, they're problems with them.

Yeah. But it turns out it's really difficult. You know, the Earth's a complicated system. Sure. And to predict accurately what's going to happen 100 years from now is really, really hard. Yeah, yeah, yeah. But when I teach about climate change, I actually don't even mention climate models until the end of the course.

It's not, I mean, there are very important tools to try to test ideas and think about what the future might be like, but I would never use them to actually make a prediction of the future, or at least make sure that I understand that there's some big error bars. There's a lot we don't understand about the system. Yeah, okay, but okay, so let's put now, let's go in perspective and talk about the changes that have taken place due to human industrial activity. What's already happened, the range of possibilities of what might happen, and then I want to talk about dealing with this through politics and technology.

That's for me one of the most interesting things about this problem. And I got to say, for me, this was partly very personal. 20 years ago, I was giving talks all the time about climate change from a geological perspective. So I would talk about paleo-climate, and I would talk about the ice ages, and I would talk about the Eocene, which was one of the last times when the Earth was very warm. And that would put sort of climate change in perspective. And then I would end my talk.

and I would sort of leave people hanging. And for me, I think the audience liked it, but it was very unsettling for me. I was like, this just feels cruel. And so I started teaching a course, and I'm lucky enough to be here where I have lots of colleagues who know a lot about this. I taught a seminar with John Holdren for undergraduates for many years,

and John studied energy systems for years. John Holden, by the way, was the President's Science Advisor in the Obama administration. Yeah. And he started the Energy and Resources Group at Berkeley in 1970, 71, 72, something like that. So, and John's just a fabulous colleague. And so we taught this course together. And for me, it was a way of learning about energy systems. Because I wanted, I wasn't happy just studying climate change. I actually wanted to understand what to do about it. And so for the last decade or so, I've taught a course for undergraduates where I actually make them design a low-carbon economy. The first sort of 60% of the course is about climate and paleo climate. So they learn all of the things we've talked about.

Yeah, sure. And then we take a switch and we say, okay, so now we're going to solve the problem. And they have to design an economy. It's for the U.S., but we talk about the world as well. And we're going to design a low-carbon economy quantitatively. And they actually see how incredibly difficult it is. It's really not easy. Yeah.

Yeah, exactly. Well, one might think it was easy. It would be done. but I'm not even sure of that. It's really hard. Yeah, because people just don't understand the risks. But, yeah. I think that's, to me, the fun part of this,

is not just studying the Earth system and not just studying the modern climate and the future climate, but actually thinking about the energy systems, they interact with it. It's interesting, call it fun. From a scientific perspective is fun, for the fact that society has to do this,

and there will be incredible societal implications. It may not be so fun, but we'll see. Yeah, I've got to say, so, um, I mean, you said this earlier, that's what makes climate change so difficult, is because we always want to push it off. Yeah. You know, some people say climate change is the most important problem of our time.

And I actually think that's exactly wrong. The reason, climate change is the most difficult problem of our time, but it's the most difficult problem because it's never the most important problem. Yeah. That's what's so nefarious about it. It never seems urgent. Yeah. It's never urgent.

It's like the frog in the boiling water. And it, it, and it, it, and it, And I think it's the combination of two cruel aspects of the climate problem. First, and this is me sort of thinking like a political theorist a little bit, but the first is that it's a global collective action problem. And we're really bad at collective action problems. Global collective action is unprecedented in the history of humanity in a sense. The free rider issue, that is, you know, why should I?

I pay money if I can sneak without doing it and let everybody else pay the money, you know, it's really hard. Yeah. Right? So, so, you know, and moreover, why should I pay money when other people aren't? I mean, that's the other thing. Why should we be the first to have a carbon tax or something like when other countries aren't? Why should we suffer? That's right. And it's real, and the problem is it's real money. Yeah. It's real cost. It's going to be hard work to fix this. So, so do Doing this globally is we've never done anything like this. Yeah. By itself, that may make this the hardest problem in the world, but there's another

aspect that makes it even worse and maybe much worse. And that is just about every aspect of the problem has really long time skills. We talked about the oceans, right? That they have centuries, maybe millennia of warming still embedded in them. The time skill of the carbon cycle, we talked about tens of thousands of years. What about the ice sheets? You know, we are, my guess is we've already probably committed ourselves to melting of Greenland. Greenland is equivalent to about seven meters of sea level rise.

Yeah, well, okay, good, okay. We're beginning to get these numbers. Right. I mean, as a physicist, you know, there's what I love about telling audiences about Greenland. Greenland is so massive, it has its own tide.

Do you know this? No, I didn't know that about Greenland. So if you actually, so Greenland has about seven meters of sea level equivalent, meaning if you melted all the ice in Greenland, the Greenland ice sheet's about three kilometers tall, If you melted all the ice on Greenland, sea level, on average, would rise seven meters, 23 feet or something like that.

And I want to step back for a second. Because when people talk, again, it's one of these things when IPCC talks about, oh, there's a centimeter sea level rise or whatever. People think, oh, who the heck cares about that? And I remember when I first was exposed to the data, the thing that amazed me is historically, looking back, and this was from ice cores in Antarctica and in the Dead Sea, I guess, carbon dioxide temperatures have fluctuated, but sea levels had fluctuated plus or minus 80 meters in the last 500,000 years or something like that, I think. Well, so the glacial interglacial cycle, so remember that, you know, 20,000 years ago,

we were in a glacial, today we're in an interglacial, or the pre-industrial, we're in an interglacial. We're kind of a post-interglacial today. During the last glacial maximum, 20,000 years ago, sea level was about 130 meters lower than today. And the reason was there was a big ice sheet over North America called the Laurentide. Boston, here we are, we were under more than a kilometer of ice. Right? Very different world.

Yeah, and that's, people need to realize that there have been changes in almost historical time, in a sense that have been huge. But they were still slow. So remember, the deglaciation where the sea levels rose from 130 meters lower up to today, that took 10,000 years. Exactly. And so it's all about time scale.

So Greenland melting. So I would just tell you about the tides of Greenland because it's a cool little fat. Let's get the tides of Greenland, and then let's talk about what happens when Greenland melts. So Greenland, seven meters of sea level equivalent, right? So if you melt Greenland, sea level goes up seven meters. Let's imagine we melted a seventh of Greenland. Okay. So sea level would go up one meter on average.

Okay. But if you were standing at the southern tip of Greenland, you would see a sea level fall by 19 meters. And the reason is that the Greenland ice sheet is so massive, it actually gravitationally pulls the ocean towards it, just like the moon pulls the top of the oceans. So if it becomes less massive, it pulls it less. It releases the ocean. Toil the rest of the world, I guess. Now, on average, the rest of the ocean is in a meter. That's amazing.

That's how big it is. I never knew. That is quite a minute. But, you know, you sort of step back and you say, wow, it's really big. Yeah. And we are unleashing these kind of forces. There's a similar story about Antarctica. By the way, Antarctica is about seven or eight times bigger than Greenland.

Yeah. So the Antarctic ice sheets massive. Yeah. So we are, you know, with the Ross Ice Shelf, for example, we could be committing ourselves to tens of meters of sea level rise, again, that could be over many centuries. Well, although you can see it. It's something that future generations can't do anything about. They can't, exactly, and we're committing them now.

And, I mean, I've been down in Antarctica, and, boy, you can see the changes. It's extraordinary. And the changes just in the last two decades in Greenland. And seven meters, just so people realize. I mean, it may sound like, well, who cares? I'm more than seven meters above sea level right now. But seven. Actually, right here.

we're a little bit less than seven meters. Oh, yeah, here in Boston, that's right. Well, so actually, right here we're standing. We're above seven meters, but most of the houses where the undergraduates live are below 23 feet. Just the effect. In all of Florida. All of Florida. But forget Florida and us.

Let's talk about Bangladesh. Let's talk about where billions of people live and we're going to have to move. Well, but let's talk about New York and Shanghai. Yeah. You know, everywhere. where all the big cities in the world, they're all affected by that. Although the rich, you know,

we're jumping all around, but I think it's important to hit some of these topics while you mention it. Yeah, New York will be, will be a disaster, but New York also has resources. But much, so maybe,

maybe you can imagine a big wall around New York. I mean, it could get Donald Trump started on that right now, but the third world, where, and again, correct me if I'm wrong, where the,

let's not call it the third world. Let's call it the developing world. developing world, where, especially in the equator level, which is poor and has huge populations, in my understanding, will also get the brunt of the problems having you do with climate change. So, you know, Lawrence, I actually think, I agree with that to some extent. I actually think the climate community has made a mistake in framing it that way. Okay, interesting. And the reason is that many people walk away,

thinking that climate change is about the poor people in Bangladesh. Yeah, yeah, okay. And you know what? Don't worry about it. It's really not about that. Yeah, yeah. There's a couple of things. This gets into the question of what some people call adaptation,

what I call preparedness. Yeah. I think preparedness is a better way to talk about it. Yeah. Because, first of all, I think adaptation sounds painful. Uh-huh. Do you want to adapt? Yeah, yeah, no, no.

Nobody wants to adapt, whereas preparing is very positive. It's what the Boy Scouts and the Girl Scouts do. Well, a lot of this, look, let's face it, a lot of this is going to require words and selling because people are not naturally tuned to think about things on that time frame of children or grandchildren. People, you know, the risk assessment, of course, in humans is just remarkably through evolution inappropriate on these timescales. Our political institutions, our business institutions, everything we have does short time

scale planning. And also small risks and baredalard risk. I mean, it was just, I had to change my plans to come here because of 737 max 8, which as horrible as that was, there are tens of millions of people to fly in those planes every day or we're flying. And, yeah, two planes went down. The risk is probably still less than you taking an Uber from the airport to hear. Yeah, but we have quickly removed all those planes because there's a one in a million or one in a hundred million chance of getting killed in them.

But we're on a slow time scale doing things with 100% likelihood of changing, but we don't think of that as a risk. this gets into this question of preparedness and the time scale issue. And I think those are those two intertwine. I have a friend named Kelsey Worth who's designed, organized something called mothers out front with the idea that mothers are particularly suited to thinking about long time scales in future generations, which I think is a very clever idea. I think we need lots of experiments like that. But in terms of the question about Bangladesh or Indonesia or tropical countries, the developing world, it is true.

True. The developing world is going to get hit hard, but it turns out that develop world's going to get hit hard too. Yeah, okay. And, I mean, look at Houston or look at the coast of Florida, the Gulf Coast after Hurricane Michael. It's like a bomb went off. Yeah. So we are vulnerable too. Now, that's not to say that many people in the developing world because they are so poor and they maybe have no place to go because of political boundaries, various conflicts. In fact, you know, you may see new conflicts arise because of migration. But here's the important point that I think the question of vulnerability is interesting. In some ways, people who are very poor are quite resilient because they have nothing to lose. Yeah, yeah, yeah. Right? And that's not to say that in any way that I'm not sympathetic to the poor people in Bangladesh, but on the timescale of sea level rise in Bangladesh, those people will move.

Well, but here's as complicated as climate systems are, and from your experience in politics, human social systems are at least equally complicated. And when you have several hundred million people who need to move, there is zero doubt, at least to me, that the sociopolitical consequences of migrations, the instability, the government instabilities will trickle throughout the world. And so the developed world is going to be impacted not just directly by hurricanes or sea level rise, but by the fact that there is much bigger instability or at least drivers of instability in the rest of the world. That's absolutely true. And certainly the Pentagon has thought about that and done some of work. I was just looking today, and this is not new, but it's still worth stressing that the same government, and we're the only major country in the world where one of the leading parties still denies, still denies, still denies climate change, that nevertheless, no matter what's being done,

said by the Trump administration, that right now the military is preparing for it at an active level, because they have to. And so the realities are there, no matter what the politicians may say. So in 2012, you know, we had just had a heat wave that summer in the U.S. 50% of U.S. counties

were in emergency drought conditions. And then that fall in October, we had Superstorm Sandy, hit New York and New Jersey Shore. And I don't know if you remember, but in the 2012 election, when President Obama beat Mitt Romney, Mayor Bloomberg came out as a Republican and endorsed President Obama because of climate change about two weeks before the election, or a week before the election. Now, I think probably President Obama would have won anyway at that point. Yeah. But it's important to understand that was a significant point. And I was serving on his Council of Science and Technology Advisors, and the president

asked us for ideas. He said, I want to do something more on climate change in my second term, and I want your help. And so I was lucky enough to draft the memo to the president that we wrote on this topic. And the first thing we said was focus on national preparedness, which at the time was considered radical. It was considered, we were trashed by many climate scientists, climate policy people. Because it, for many reasons, but it makes it, one of the reasons that people are concerned about is they think, oh, you're throwing up your hands. You're saying, let's not, let's not deal with climate. That's what George W. Bush said, we'll just adapt. We don't need to do anything. We'll just adapt.

Yeah, which is, of course, not just equally worse. Now, we pointed out that our, that was our first recommendation. Our second, third, fourth, and fifth all had to do with reducing emissions. Yeah. So it wasn't like we were giving up by any means. But, but. After these catastrophic weather events, we were spending almost $100 billion that year on climate-related damages. Yeah, instead of... We said, you know what?

This is actually important, but there was another point that we made in that report that I think people have lost sight of, which is... And this may get to a little bit of human psychology in the way people respond to this kind of damage. Collective action, global collective action is hard. Why should I do something if China or Russia aren't going to do anything?

Long time scale's hard. Okay, I care about my children and grandchildren, but I've got problems now. I'm not going to pay money so that they can be okay. Now, that's all hard. What do people really care about? I actually think they care about protecting themselves, protecting their families, protecting their communities. That's very primal. So what we argued to President Obama was that if you actually focus on,

on people's vulnerabilities locally. And it's different in Florida than it is in Boston and different in Boston than it is in Colorado and different in Colorado than it is in Iowa. So different climate impacts. You know, if you talk about sea level in Colorado, not so much.

Yeah, yeah, right? On the other hand, in Florida, that's a big deal. So you have to think about what local vulnerability is and help communities prepare for climate change. That is fundamentally a positive thing, protecting your community, protecting your home. That's just a good thing.

And by the way, it also kind of gets rid of the concern about attribution of storms. You know, every time there's a big storm, people say, is it caused by climate change? And you sort of climate scientists stumble all over themselves saying, well, statistically, it's related, but we can't say that any individual storm, blah, blah, blah, and already the viewers have turned off. The fact is, if you're prepared, it doesn't really matter whether climate change caused the storm or not. You're prepared. It's a good thing. Yeah.

Preparation. And inevitably, again, it makes such economic sense because preparation costs so much less than dealing with after the fact. If you're getting people to prepare and in doing so, they're actually learning about their vulnerabilities. Yeah. We believed that it was likely that people would say, you know what? Maybe we should support some policies to actually fix this problem once and for all. Because the more I learn about this, this is not a good thing.

Yeah. If I'm in Miami Beach, I'm saying, okay, I can prepare, I can protect my home, I can build some sea walls, I can put some things on stilts, I can put some sum pumps in. But this is just, this is not going anywhere good. Maybe we need to stop this. Yeah, although the, you know, the problem, of course, is also, at least when we're observing the current political climate, it makes you susceptible to people who simply have other reasons for not wanting people to deal with this from saying, well, look, these people are scaremongers. They want you prepare for things that aren't going to happen or prepare. You know, they're attributing things to the wrong thing, and they're trying to get you to spend money because the government wants to spend money. So there are people like that, and, you know, we've spent some time.

There's a whole party of the people like that. There are, you know, some, we talked to some of the physicists who are hostile to this when we were in Mexico together a year ago. When you and I were, yes. But the reality is, I think most people, Get it. In fact, the polls say 70% of this country actually is concerned about climate change. But are you at all concerned about the fact that one of the people that we were with in Mexico, who was just totally hostile to any notions, is now the person who's President Trump's advisor on this whole subject? Am I concerned about it? Not any more than I'm concerned about anything else going on in Washington today.

I think the important thing is that look what just happened in Nebraska with the floods. I think you talk to farmers in Nebraska, you talk to farmers in Iowa. They actually get it. And I think that the tide, well, the tide is rising, but I think the important point is that I think we're ready for a big political transformation. And I think what this has to come is it has to become a postpartisan issue. Yeah. A few years ago, I spent some time with Representative Eric Cantor.

Do you remember Eric Cantor? Yeah, I remember Eric Cantor. He was the House Majority Leader And he was very conservative He at least in the press They portrayed him as you know Anytime John Boehner wanted to make a compromise Eric Cantor wouldn't pull him back to the right

And I spoke to Eric Cantor in his office About climate change He asked me to come in And I was a little surprised Because I was on President Obama's Science Council Yeah And so like why are you talking to me?

Yeah And he said we talked about climate change. He chastised me a little for some comments I made about coal. But then he said he liked how I talked about the problem and about technology. And he wanted me to help his staff

design a strategy for conservative Republicans that would be acting on climate change not through denial. And I was a little surprised. I said, why are you doing this? And he said, number one, we've purged all knowledge from our party

so we don't actually have anybody to advise us on them. And number two, Republicans under 35 think we're crazy. And he saw the writing on the wall that basically the Republican Party needs to switch. Yeah, no, this is a really important point. I think you're absolutely right. One can look around, and I think people are ready for change. Now, remember, he lost his primary three weeks later. He lost it.

I know, exactly. So I never got to do this work. And let me say, and I was a little concerned when you talked about this, interestingly, when I was chair of the board of the bulletin atomic scientists, one of the things we did, we had an event in Congress where we talked about climate change and other existential risks. And I was saddened at the time that it was open to all staffers. And I was hoping, and what surprised me was that only the democratic staffers came to that. And I was really surprised because I thought it would be a bipartisan issue of just learning about the science.

And by the way, I should, since we should make full disclaimers, You were not only on Obama's science counsel for while he was president. I was on his advisory panel when he was running into, so we all have our connections. But here's the interesting thing. I think that the path forward in this country, the real sea change will happen when both parties are competing for better solutions. Yeah, but I also think it'll happen within its generational.

I think you hit the point that Republicans under 35. I think that what is clearly happened, and it's good. And in spite of the incredible amount of money being spent to obfuscate the issue, that generationally we're beginning to see, and, you know, young people be concerned about many things. And anytime young people are concerned about many things, I think it's a great thing. And that's a property of having grown up in the 60s, I think. But once you have a generation that wants to change it, it doesn't really matter what the politicians are going to do. And so are you encouraged?

There was this young student strike here in this country. And I think at Stockholm, there's a young girl who is, there's all these, I mean, I'm not sure. So I had dinner last week with the Sunrise Movement, which is the group who started the Green New Deal. These are incredibly thoughtful, interesting young people, 25 years old, the founder, a lovely woman named Varshani Prakash, fabulous. Now, at 25, is she an expert on energy technology and policy? Of course not. But what she gets, which frankly, a lot of people in the climate policy community haven't gotten over the last two decades is the urgency.

Yeah. She says, we need to do this now. We're going to do this in 10 years. Now, there are all sorts of technical reasons why that's not possible, and I can explain why that. You just can't, and the reason is the energy system of the U.S. the energy system of the world, it's just too big, too much cement and steel, you can't possibly build all that infrastructure in 10 years. And they say, why not? And you know what? I think they're

opening up an opportunity to do something way more substantial than anyone imagined. And I think that's really important to watch. I think that, yeah, that you made a key point that was that what we're doing now, what's already been done, forget what's doing now, is going to, you know, is going to impact our children and our children's children, we have left them a legacy. And it is, they're the ones who are going to suffer. Now, you can always say, well, if you care about your grandchildren, care, but, but it seems to me that that, therefore, is the community of people who should be most receptive because you're younger than me, but still we're not going to, we're not going to witness the most severe implications of what's already been done to climate.

And so it seems to me that we really need to reach the young people, not just because they're the future, but because they're the ones who are really going to have to live for that. Yeah, I think we need to reach everybody. Young people, unfortunately, don't vote, and that's a terrible thing in this country. But they will. But the point is, I guess, you know, it's funny, you know what happens, Lawrence? Young people become old. It's really strange.

I know it happens. But if they're radicalized when they're young, I can't help but think that the fact that I grew up in the 60s has impacted on my politics now that I'm in my 60s. Anyway, so that's one thing. So here, I think there's a couple things to say about technology that's really important. First of all, in 2009, when Obama came into office,

we were in the midst of one of the most terrifying financial crises. And most of the leading economists in the U.S., both conservative and progressive, they really believed that the whole financial system of the U.S. could topple. Yeah. And it could be a total collapse. Yeah. They were terrified.

So we, remember, a Republican Congress passed a trillion-dollar stimulus package. Yeah. Unbelievable. Why? And Democrats bailed out the big banks. Yeah. Things you wouldn't expect on either side. Things you wouldn't expect.

because people were scared. Recently, a radio show talk host said to me, well, did President Obama miss an opportunity there to do the Green New Deal? Because we had a trillion dollars. Yeah, yeah. You know, he actually spent close to $100 billion on energy systems, which was extraordinary.

But here's the difference. In 2009, the price of solar and wind were about five times what they are today. we have seen an extraordinary change in technology in terms of cost. Five years ago, six years ago, Massachusetts, Boston was considering Cape Wind, which was windmills out in Nantucket Sound. The Kennedys opposed it. They didn't like their view from Hyannisport being damaged.

But a lot of people opposed it for one simple reason. It was almost 21 cents a kilowatt hour. That's the wholesale cost, not the cost of consumers, right? You probably have to triple that. I mean, that was like three times the cost of the power they were competing against. Just this year, Massachusetts signed a contract with Vineyard Wind to build a 400-megawatt offshore wind farm at six and a half cents a kilowatt hour, a factor of three lower in just a few years. So the point is that we have technology today that we didn't have then.

Electric vehicles, which, you know, still are too expensive. Yeah. But you know what? We're beginning to see a change. You know, not 2018, 2% of electric, 2% of new vehicle sales were electric vehicles. Yeah, which is... That's extraordinary. Which is extraordinary, given, you know, a decade ago.

So, again, are we there yet? No. What do you, let me just, I'm going to try and be the devil's advocate. What do you say? And I've heard this for some people saying, yeah, this is all good stuff, but it's going to get better. So why do it now? I mean, you know, solar and wind will be cheaper 10 years from now, so let's wait till 10 years from now to do that.

What do you say to that? The answer is perhaps, but right now, offshore wind in Massachusetts at 6.5 cents is actually, you know, substantially preferable to almost everything else. You know, a few years ago, just a few years ago, I had a student do a study of renewable energy choices in Massachusetts. And offshore wind or bringing wind from far away, We're far, far more expensive than building a cable up to Quebec and bringing hydro power down from Quebec. But you know what? That's no longer true. Offshore wind has gotten really cheap. It's almost directly competitive with natural gas. And in the winter, we actually don't have enough natural gas pipeline capacity. And so natural gas power is really expensive.

And so in fact, offshore winds could be a very good deal. It's really competitive. So I think those things are really close. Okay. What do you do about there are powerful groups with lots of money that spend that money to direct public opinion, much more than the research budget of the IPCC is spent trying to obfuscate this issue. And so these are rational policies, but rational. policies aren't always enacted.

Is there a way to get this message through in a way that people... So now you're talking about communication. Yeah. I think there is a way. I'm doing an experiment with a colleague of mine. A friend of mine is a chief marketing officer at a large marketing firm in New York. We've created something we're calling potential energy. And what it is, it's actually never been tried.

What we've got is we've got about 20 of the world's best advertising agency. all pledging to work pro bono. Okay. Doing serious marketing research like social science. Yeah, sure. Coupled with creative work. These are the companies that do advertising for Nike and for Coca-Cola and for, you know, these are the most creative minds in the business.

And they want to work pro bono because they care about this issue. And we're trying to raise some money to actually produce spots. We're focusing regionally. So we're starting with Florida. Okay. But this has really never been tried. Environmental groups have used advertising agencies to project their message. But that's not quite the same thing as saying, let's look at the research and actually figure out just as they do with products.

You know, when they take Coca-Cola, they're not marketing just with creatives. They're doing very careful research about who is the target audience and what is it that they're going to respond to. Well, it's great to doing this pro bono. It'll be interesting to see. So we're going to see if we can try this. Again, to me, you have to take shots on goal. You've got to try. Just try everything and try a lot of things.

See what works. We used to say, even in the nuclear issue, what will be the Sputnik moment? And people keep saying, you know, in terms of dealing with not just nuclear weapons, but other existential threats like climate change. You know, Sputnik was somehow, it changed this country in terms of the decision to put resources and education and science. There's one other thing that's really important. Years ago, in 2004, I had an event at Harvard with Vice President Al Gore and Larry Summers. It was very interesting combination. Larry Summers was president of Harvard

and had just stepped down as Treasury Secretary in 2000 in the Clinton administration. And Larry Summers got up on stage and said something I think that's very wise. He said, and this is in 2004, just after the Kerry election, losing to Bush. Larry Summers said, you know,

action on climate change is going to take a really long time, much longer than people think, in Washington. But when it comes, it's going to come really fast. And the role of a university is to be prepared with a plan because the staffers in Washington are not going to do the careful analysis and discussion and thought that a real plan for dealing with this requires. So we need the plan. And I think that's really sage counsel.

Now, that plan needs to be constantly updated to different technologies and different things. 10 years ago, you wouldn't have predicted that solar and wind would have gotten quite as cheap as they've gotten. So it's changed everything. Yeah, no. And I put my optimistic and my pessimistic hats on alternately. I hope that I'm not always optimistic that good plans will be, even if they're available, will be. So I actually don't like the optimism versus, I don't like the optimism, pessimism framing. And I'll tell you why, Lawrence. I have a lot of colleagues in this field, in energy policy, climate policy.

who say, I've heard them say, well, we have to give people hope. We can't let people despair. Yeah, yeah. And I step back and I think about it and I say, you know what? I'm a scientist. My job is to observe the natural world with as few biases as I can, you know, I try to shed all the biases I have. It's not that I don't care about nature. I don't, you know, I care about all these things.

But when I'm observing the world, I try to put those perspectives aside and see things as they are as best I can. Yeah, sure. And then describe it. Yeah. And to me, sometimes in my class, people say, boy, you sound so pessimistic. I'm like, no, actually, I think about myself as an optimist. Yeah. I just don't think that pessimism or that optimism based in delusion is very helpful. No, no. I mean, what we do, what people deserve is reality. But, you know, when even we've done public events. I think what we, is just what you said, the reality is dismal, but that doesn't, but what we don't want people to do is say there's no, that they can't do anything. So there's one aspect of this that I also think some of the environmental NGOs get wrong,

which is human capacity to adapt. Yeah, absolutely. Humans, I, would I have a lot of faith in, and maybe this is just faith, but I, but I think there's historical justification for it. Humans are ingenious. We are the most innovative. We are the most innovative. incredible species. Yeah, and I think a lot of predictions miss the fact that technology and human adaptation will do things you hadn't expected. I've been giving talks about this

where I sort of say, look, the timescale of energy systems, the timescale of climate change, they're all long. Yeah. You know, there are many decades at least to many centuries to millennia. This is a killer problem. It's the collective action problem. It's the long time scale problem.

Humans are really bad at that. But there's a great quote from H.G. Wells that I love. He said, we are kept keen on the grindstone of pain and necessity. And I think there's some truth to that. That's not to say that humans won't suffer. Many humans will suffer terribly, maybe even die because of climate change. And we need to take that seriously, and that's a terribly moral obligation we have to the future. But I also believe that the 21st century, because of climate change,

is likely to be the most innovative century in our history, but not necessarily in energy technology. It's going to be in things like architecture. There'll be things like transportation, agriculture, maybe even governance. You know, the fact is, dealing with climate change,

we haven't talked about solar geoengineering. Well, no, we're going to get there. Things like that require new global governance that's way beyond what the UN can do. And you know what? I actually think humans will muddle through and figure out By the way, nature is going to get screwed. Yeah.

Right? Yeah. The fact is, you know, the natural world, first by human land use and now climate change is going to come finish the job. It doesn't mean there won't be natural things. There'll be plenty of wild space and trees growing and birds and animals. But, you know, it'll be nothing like what's going to be Earth 2.0 or 3.0, yeah. That's right. And, I mean, in terms of adaptation, I think you're right.

I think it was Sarker said the humans can learn to live in the trunk of a tree if they need to. Don't underestimate how adaptive humans are. Humans are incredibly resilient. And by the way, there's sometimes when you hear people talk about climate change and you, you know, say, oh, four degrees is the end of the world. And you sort of say, no, it's not. 50 million years ago, the Eocene, the earth was probably eight or ten degrees warmer than today. And you know what? Had we been living there, we would have been just fine.

Yeah, yeah. Now, the problem is getting from here to there in a thousand years or 500 years or 300 years, that's really stressful and a lot of humans will suffer. But there's nothing inherently unlivable about that. Well, there's nothing inherently unlivable. Let me, let me, let me, I'm not to worry that physically it's impossible for humans to live under those conditions. What I'm more worried about is that the transition will cause instabilities that will cause human to use the weapons of mass destruction to end human life on Earth. So I totally agree.

I think that's more. The big risk is that our social systems and, you know, when humans are stressed, often it's not very pretty. Yeah, yeah, I think, so I think that's a more realistic concern than ending life. I often hear it saying this could end life on Earth. Well, it won't directly, but it could cause humans to take the action to do that. Before, I want to talk about, you know, we've skirted it, but I want to make it clear to people who haven't heard of this issue, exactly what the change is in greenhouse gases. We really haven't said what the impact of human industrial activity is

on that global historical time scale, just so people could put in perspective. We skipped it, and I think it's worth you spending a few minutes just giving that. Sure, sure, sure. So 20,000 years ago, last glacial maximum, we have a kilometer of ice where we're standing in Boston, in Cambridge. Carbon dioxide levels were about 180 parts per million.

Okay. The pre-industrial, the interglacial, about 280 parts per million. And we've seen that cycle periodically over the last few couple million years. When Dave Keeling started measuring CO2 in 1958, it was already at about 315 parts per million. So up about 35 parts per million from the pre-industrial level. Today we're about 412 parts per million. So we are really going into completely unexplored territory. That has not been seen on earth in at least the last few million years.

At least probably four or five million years. And by mid-century, we're going to be well above 500 parts per million. And now we're talking about maybe 30 or 35 million years. So we're doing something extraordinary. And it's really important to realize that when people talk about it, you see parts for million, who the heck cares about parts for million, that the natural cycle has not anywhere approached this level. And, and, moreover, as the natural cycle has varied over that, climate has varied tremendously.

It's not as if, it's not as if, sure, people can say, well, it didn't never varied much, but who cares? But it varied a small amount and climate change dramatically. We're doing something that has never been, an experiment that's never been performed, at least in the last few million years. That's exactly right. And we can look at the paleo climate record to get a pretty good sense of how sensitive the Earth's climate, system is to changes in CO2. Because we have CO2 reconstructions and we know how much the temperature changed.

And the answer seems to be that the sensitivity, that is, per doubling of CO2, you get a surface temperature change of about three or four degrees. Now, what we've experienced over the last hundred years is only about, you know, maybe one and a half to two degrees per doubling. Because we've only warmed by a little more than a degree, and we haven't yet doubled CO2, right? Yeah, but we've got the oceans. But that's it.

So you have the ocean. So the other half is still coming. Yeah, the other ocean. So that's probably the resolution of that. So it's probably about three degrees per doubling. And just understand, three degrees doesn't sound like that much. But remember, the difference between the last glacial maximum, sea level 130 meters lower, you know, North America, half of North America covered with ice, the ice coming down to New York City.

Completely different world, right? That was five degrees lower, colder. Right? So we're talking about probably in the next 100 to 150 years being five degrees warmer. It's extraordinary. Putting that in context, I think, is really important because to me, when I talk to people, I say, well, we don't know what's going to happen, but here's what has happened, here's what may be possible, here's the context. Do you want to gamble?

Do you feel lucky? Now, speaking of gambling, we've talked about adaptation or preparedness and the reality of the social difficulties. Some people might say, well, look, I mean, and you would still say, look, there's this carbon dioxide that's going to impact on our children, our children's children, our children's children, and on, can't we do something to help them? And a lot of people are talking about geoengineering is a way to not just be prepared or live with this new future for the next thousand years, but change it and take it back, either somehow removing carbon dioxide from the atmosphere or doing things like blocking the sun or. So understand that those two things are really, really different. And we've collectively, unfortunately, called both of those things geoengineering. I think that's a terrible mistake.

I agree with you completely, because one involves, we know what will happen if you remove carbon dioxide. We don't know what's going to happen if you put... So removing carbon dioxide from the atmosphere, first of all, people should understand that most ways of doing it are incredibly expensive. Yeah, it's...

There are a lot of Silicon Valley entrepreneurs who think that they're going to invest in some magical technology. And what they don't understand is, even if it gets as cheap as some of the advocates say. With $100 a ton, it's still incredibly expensive. As long as some other countries are still burning fossil fuels, why would I pay to remove it?

You know, think about it, you know, you're on a lake, and your neighbor across the way is on the same lake. You both have houses on the lake, and there's some pollutant in the lake, and you're paying to take this pollutant out, and they're putting it in. Yeah. Like, that's not going to happen. And by the way, we're not talking about, side payments of a little bit of money, we're talking about, you know, trillions of dollars per year.

Like, this is not, this is not a small amount of money. So, so, but there's another point, even if you did that, even if you could convince our country, for example, to spend Pentagon-scale dollars on removing CO2 from the atmosphere every year, you'd need to do it for the next hundred years. It's inherently slow. Yeah. Because it's, it's on the same time scale that we burn the fossil fuel. and put it in.

So, I mean, people forget that. The world is putting in 40 billion tons of CO2 a year. That's what I was saying, 40 billion. Right. Yeah. So the idea that even if you took out a few billion a year, you'd have to be doing it for. Unless, of course, I mean, yeah, you're right.

Undoing it would take a really long time. So make it practical would require some kind of seed change in technology. It's not clear if the laws of chemistry and physics allow such a change. And the fact that Bill Gates and a variety of other entrepreneurs are putting money into these companies, a colleague of mine, David, Keith has a company like this that's building a factory to scrub CO2 from the atmosphere. And we built a group at my old university. I know.

You know what? I don't think it's going to amount to anything, but I love that it's happening. I have no problem with people. Me too. But the argument, you know, but if somebody asks me as an investor, should I invest in this because are they going to make money in the next 20 years? Like, wait a second. At least not the kind of money they're thinking.

Okay. But the other kind of geoengineering is a total. different things. Exactly. Let's get out of the kind because there's discussions of it, but there are concerns that one, at least that I have, so maybe you can... So solo geoengineering, it's an old idea, right? It was in a presidential report to President Johnson, okay, in the 60s. Okay, so this is an old idea. This was a favorite idea of Edward Teller, which is a good reason to sort of be skeptical of it. Well, or be concerned, yeah, yeah, that's right. And there's certainly people, you're irresponsible.

responsible in this who say, oh, we should just do it because it's cheap. Not realizing that what we're talking about, and when I say solar geoengineering, I'm not talking about, so let's say there's different ideas. Some people say we can make low-level clouds that will reflect sunlight and cool the earth. Other people say we can put aerosols in the stratosphere and reflect sunlight. Other people say we could put mirrors in space. Yeah. Now, I'll tell you, I think the only thing we're talking about is the stratospheric aerosols. Yes.

Not everybody agrees with me, but let me explain why. The space-based mirrors, lovely solution, unbelievably expensive. Yeah, it just seems not going to happen. It seems very Star Wars like that. Very expensive. The low-level clouds have the opposite problem. They may be cheap, but the problem is the time scale of control is really short. They last hours to maybe a day.

Which means if you're going to use it to control the climate, you need to be doing it all the time. No interruptions. The time scale of stratospheric aerosols, depending on a lot of. how you put them is one to two years. Yeah, yeah. That's a time scale that you still need to keep doing it. But, you know, if you have a couple weeks of crisis, you can... Well, yeah, no, the aerosols, I was talking about the low-level clouds.

I'm not... I think clouds and their impact on the... The aerosols with a couple, sort of one-to-two-year time scale, to me, that's the right time scale of control that's appropriate. Oh, by that. Now, you're absolutely right. We don't understand enough about exactly what it does. Remember, reflecting sunlight is not the same as reducing greenhouse gases. The physics work differently.

For example, night and day, right? The greenhouse gases work 24-7 because the Earth's radiating heat all the time and the greenhouse gases are working all the time. Reflecting aerosols only work when there's sunlight. So it changes the day-night difference. There's all sorts of subtle ways that this is going to change the Earth. It's not going to perfectly compensate for greenhouse gases. It's imperfect.

But it is instantaneous. If you did it tomorrow, the climate would cool tomorrow. Yeah, yeah. Okay? So that's kind of cool. Yeah. The best studies we've done show that actually it works a whole lot better than most of us thought. That the best models we've done and we've done many, many different generations and people have tried to show all the problems.

Is it perfect? No. In particular, there are changes in precipitation that may be problematic. But you know what? If you compare it to not doing it, then when I get it, public talks about it, I use Winston Churchill's quote about democracy. You know, the democracy is the worst form of government in the world, except for all the others. I think solar geoengineering is the same. I think solar geoengineering is a arrogant,

crazy, techno-fix, awful way of dealing with the climate problem. But it may be the better. Except for the alternative, which is letting the climate system happen. People say, oh, we should just take CO2, we should just remove the CO2. And you say, I wish it were that easy. Yeah, if it were that easy. I mean, that's the obvious, if we could do that, that's the obvious solution. What is dangerous and what a lot of people get uncomfortable about solar geoengineering is what they call the moral hazard, the idea that by doing it, you reduce the pressure on reducing emissions, so people keep going. And that is a real concern. But you know what? To me, you know, we're talking about human misery. We're talking about the end of nature. So,

You've got to think of drastic problems. And here's the other point. This is a mistake that I think a lot of physicists made in the Manhattan project. They thought they were going to make the decision on whether to use the technology. It's not our decision. And so I feel like we actually, so what we're doing at Harvard is we've created one of the first big research programs on this subject. And the reason is, I feel like we have a few decades to figure out all the possible things that might go wrong. Already, for example, I think we've made a big difference.

I think the research community, not just at Harvard, but around the world, if 10 years ago, if you were to talk about solar geoengineering, the way you, and if say somebody wanted to do it, say some country that China or the U.S. wanted to do it, they would inject sulfur dioxide or sulfur particles into the stratosphere, it would make sulfate aerosols, get oxidized, and reflect sunlight. But what we learn now is that that would come with a very big risk. risk of hurting the stratosphere ozone layer, which protects us from UV radiation. So what we're talking about now is putting other types of particles, maybe calcium carbonate, maybe other things that actually wouldn't, they might actually help the stratosphere ozone layer.

So that's the result of research. The point is, it's not our decision, but it is our, we have the potential power to help nudge the decision makers about how they do it and if they do it. And I think we need to study, to me, I've been very insistent that all the money we put into how to do it, an equal amount of money should go into what are all the possible ways it could go wrong. Well, absolutely. Because we need to essentially do a serious risk analysis of this. And, you know, the problem of course, actually, let me say, the problem with all these things is that often what goes wrong is what you don't perceive.

But the good thing... But let's get a whole lot of good smart people trying to think about all the problems. So, yeah. And for me, the one solace is, as you said, is it's got a half-life of a year or two. So you screw things up, at least you're not screwing up for 10,000 years.

But understand that it's addictive. So when I say, I personally think that we're likely going to need to do this because I think the alternative is worse. Yeah. But remember, the best analogy I've heard is that it's really like morphine. Which is, yeah.

So solar geoengineering, putting aerosols in the stratosphere, it legitimately removes some of the pain of climate change. It is possible that we could, for example, freeze Greenland and keep it from melting more. Hard to put the ice back, but at least we could keep it from progressing. But understand that it doesn't fix the core problem. And so it's a little bit like, you know, you have an appendicitis. You can take morphine.

And by the way, you want that morphine, they operate on you because having surgery, serious surgery, without any anesthesia, you'd be in misery. But if you only take the morphine and never actually get the appendicitis taken care of, it's a bad idea. Yeah, there's a line from the Rocky Horror Picture Show related to that too about affecting the symptoms and not the cause, but that's cool. And here's the other analogy that's important.

It's addictive. Yeah. Because once you start doing it and you keep emitting CO2, CO2 gets higher and higher, you keep doing more of it. But now, if you'd have stopped up, it would be a lot worse. The climate would suddenly warm abruptly, and that would be a disastrous. Look, this has been a fascinating discussion of what is not an easy problem, but unless we talk about all these options, unless we inform ourselves of what the issues are in a realistic way, then we're not going to go anywhere. So I'm just so happy we had this chance to do some justice to the many aspects. And we

could do this another time for another two hours. I'm sure we could dig it more. But thanks a lot for coming, Dan. It's been great. Thanks. Thanks, Lawrence. The Origins podcast is produced by Lawrence Krause, Nancy Dahl, Amelia Huggins, John and Don Edwards, and Rob Zeps, directed and Gus and Luke Holwurda, audio by Thomas Amos, web design by Redmond Media Lab, animation by Tomahawk Visual Effects, and music by Rickalus. To see the full video of this podcast, as well as other bonus content, visit us

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