Sean Carroll's Mindscape: Science, Society, Philosophy, Culture, Arts, and Ideas - 276 | Gavin Schmidt on Measuring, Predicting, and Protecting Our Climate

Episode Date: May 20, 2024

The Earth's climate keeps changing, largely due to the effects of human activity, and we haven't been doing enough to slow things down. Indeed, over the past year, global temperatures have been higher than ever, and higher than most climate models have predicted. Many of you have probably seen plots like this. Today's guest, Gavin Schmidt, has been a leader in measuring the variations in Earth's climate, modeling its likely future trajectory, and working to get the word out. We talk about the current state of the art, and what to expect for the future. Support Mindscape on Patreon. Blog post with transcript: https://www.preposterousuniverse.com/podcast/2024/05/20/276-gavin-schmidt-on-measuring-predicting-and-protecting-our-climate/ Gavin Schmidt received his Ph.D. in applied mathematics from University College London. He is currently Director of NASA's Goddard Institute for Space Studies, and an affiliate of the Center for Climate Systems Research at Columbia University. His research involves both measuring and modeling climate variability. Among his awards are the inaugural Climate Communications Prize of the American Geophysical Union. He is a cofounder of the RealClimate blog. NASA web page Columbia web page Google Scholar publications Wikipedia

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topics to cover. And I love getting these, by the way. Many of the episodes that we've done have been arisen as suggestions from audience members. I get way more than I can possibly say yes to. So if you make a suggestion and it doesn't get followed up on, sorry, don't feel bad about that. There's just a numbers game going on. But one topic that has gotten a lot of requests in recent years is the climate and climate change. And we haven't done a lot of climate change. We have done some, but the most pointedly climate-centric episodes that we've done were quite a while ago, Michael Mann, Remez-Nom, people like that. And it's not random that hasn't happened. It's sort of my fault. I have a feeling that, you know, obviously the science of climate change is incredibly

interesting. It's very intricate. There's a lot going on, a lot to think about. But there's also a political, social aspect to it, which to me is incredibly frustrating. Not because there shouldn't be a political social aspect to it. There's a political problem to be addressed, both within countries and internationally. We need to do something about this. But my attitude is that we should all know by now that we should be doing something about that. And it feels a little repetitive and a little frustrating just say the same true things over and over again. I didn't want to fall into that trap. So I'm here to confess that I was completely wrong in that attitude. That was a bad attitude to have. Part of the reason why I changed my mind was because there is something new that was a little bit

surprising, namely that over the last year, the temperature of the earth has been even warmer than it should have been, according to the climate models. So something is not quite fitting, and that raises a new scientific question. So I finally said, all right, it's time to figure this out, learn something, and Gavin Schmidt, who is today's podcast guest, is the perfect person to talk about these kinds of things. Many of you will have heard of Gavin before. He's not only a very respected climatologist, director of NASA's Goddard Institute for Space Studies, co-author of the various IPCC reports, et cetera, but he's also active in public engagement, which is very, very important, more important for climate scientists to do than physicists or philosophers.

Let's put it that way. The real climate blog is one that he and a group of friends founded. I learned by talking to Gavin before today's episode that Cosmic Variants, which was the group blog that I was a part of for a while, was one of the inspirations for real climate starting up. So I thought that was very nice. But they're still going strong. You can still follow them and check them out. So anyway, Gavin is not only very knowledgeable about these things, but incredibly articulated explaining what is going on and keeping interest high. And I think hitting the right notes of giving us insight into the science while nudging us in a productive direction in terms of policy and politics and things like that. So I think, you know, again, I was wrong, my fault,

long overdue this episode. I think this is going to turn out to be one of the best episodes of Mindscape that you will listen to. Occasional reminders. If you like Mindscape, you can support the podcast at patreon.com slash Sean M. Carroll. Drop a buck or two for every episode of the podcast. You get a warm and fuzzy feeling. Also add free versions of the podcast and the ability to ask questions at monthly AMAs. And it's just a good thing to do. You should support good things that you like in a relatively low level of cost, I think, overall. I think it's worth it in an hour of every week. Anyway, with that, again, I think that this is a great discussion of some super important topics in a very clear way. And we get in a bit sciencey in here. There's some isotopic

abundances that we're going to dig into. So let's go. Gavin Schmidt, welcome to the Mindscape podcast. Thank you very much, Sean. Good to be here. So the climate, how's that going? How's the climate doing these days? Well, let me tell you. So, it's It's totally abundant to anybody who ever sticks their head outside that the climate is changing. We are seeing in all the data sets in the temperatures, on the land, in the ocean. We're seeing it in the ice. We're seeing it in the sea level rise. We're seeing it in the change of weather extremes, the intensity of rainfall, the heat waves,

the change in the plant hardiness zones that are moving upwards. and polewood on a, you know, maybe decadal basis, not quite every year, but on a decadal basis. You know, New York City, where I live, is now subtropical, it turns out, and it didn't use to be. But so that makes a difference to what you're planting. It makes a difference to what you're seeing. It makes a difference to the pests that you get. And we're seeing changes in an invasive. You know, I can go through the litany of stuff that people have seen.

But it's everywhere and the evidence for that change is everywhere. And if that's all there was, it would be all. Well, that's interesting on what's going on. But it isn't all that's going on because we actually understand why it's changing. And we have been predicting why it was going to change, why it is changing, and why it will continue to change for many decades now. and we have been doing so successfully. And the answer is,

it's us. And it's our emissions of greenhouse gases, notably carbon dioxide, methane, carbon, the CFCs, changes in ozone, changes in nitrous oxide. It's a whole list of things that we're doing, deforestation, air pollution of various sorts.

We are now, now very clearly geophysical force. And our imprint on the system is comparable to, you know, almost the biggest things that have happened in the last 65 million years. And down. One of the complaints, there are doubters out there. We're not going to give them too much airtime, but there's a lot of people who want to throw up reasons to be skeptical of the whole climate change story. And, you know, one for a long

time has been the climate is really complicated. It's a very complex system. It's very hard to model. We know what's going to happen. And, you know, to be honest, I'm interested in your perspective on this. I never quite bought that argument, but I wouldn't have been shocked. You know, like the climate is very complicated. There are a lot of things. It's kind of amazing how well you folks have done in modeling it. It seems like a very hard thing to do. Yes. Yes. And this is something that is far, I think, well appreciated. You know, we've been doing, you know, climate modeling, you know, at a serious level since the beginning of the 1980s, right? So that's over, that's over 40 years. And the amazing thing was, at the beginning, nobody thought it would be useful, right? You know,

the climate is too complicated. Look at all the weather. Look at all the details. everything is like there's so much heterogeneity. Like you're never going to be able to get something on the, on the global scale, re-reational scale that is going to be anything other than academic. But the fact of the matter is, is that a lot of that noise cancels that. A lot of it is just, in fact, noise.

And you can extract the signal from that noise in models relatively easily. And then in the data, there's a little bit more noise and so it takes a little bit longer to come out in the data but you can see it and it turns out

that that signal is in fact far more robust to the details than we really anticipated you know 40 years ago and so the climate

is complex right I mean if you ever saw my TED talk but you know but that's how we start The climate is enormously complicated. You can see so many different feedbacks and interactions between the clouds and the particles and the ocean and the land. And it is very hard to keep track of. But the models that we have created, even the first set of models that we created, 40 years ago, have managed to skillfully predict what.

happened in the global mean temperatures, in the pattern of temperature change, in the, you know, the rate of which we were warming and the impacts on rainfall and things like that. They didn't get everything, right? They, you know, we still struggle with getting, you know, the sea level predictions right because, you know, you need to include the ice sheets, the dynamic ice sheets and underneath the ice sheets and all of the other things that happen to water. That's still kind of very much at the cutting edge. You know, we don't get, you know, we haven't been able to successfully predict

when the tipping points of rainforest systems are when you have deforestation and drying and when do they not work anymore. We don't know that. So there are still kind of detailed, complicated questions that we're still working on. And we can get to, to perhaps some of the ones that are relevant for exactly what's going on right now,

2023, 2024, a little bit later in the talk. And so there are very much open questions, but the big question, right, the big issue, like, why is it different now to what it was 100 years ago? It turns out that the answer that we came up with 40 years ago has stood the test of time and it's not going away. And I definitely do want to get into the modeling especially because that's just a fascinating scientific subject. But let's be good empirical scientists and measuring a little bit. Absolutely. My most basic question is, what does it even mean to talk about the temperature

of the earth or the atmosphere? I mean, the temperature here in Baltimore is not the same as the temperature in Oslo or in Cairo. So how well defined is that? Is that something that is a good guess? We all agree. Is there a dispute about what it means? Well, no. I mean, like, you know, temperature is a three-dimensional field, and I can average it over any two-dimensional surface I want, and I can get a number. Now, the question is, is that meaningful, right? So, so, you know, the issue is not, you know, can I define a double mean temperature? The issue is, is that meaningful. And you might think that it might not be very meaningful because, well, you know, all of these things are nonlinear, and so it matters that somewhere is a little bit warmer and somewhere is a little bit colder. And somewhere is a little bit cold. that doesn't give you quite exactly the same thing as if everybody was the same was at the same temperature, right? You know, so, and that's, that's a valid, that's a valid point. But it turns out that it's a pretty small point. The, the kind of heuristic model that we have of the climate where, you know, the sun brings the energy in,

the infrared goes out, and that's kind of mediated by effectively the surface temperature. it actually works pretty well. I mean, it helps explain, you know, not everything that you're seeing, but it does help explain like the bulk issues. And that's why those early models were so successful, right? Because they didn't do very much else other than like kind of chop the world up into quite large boxes and average those together. And so as we've gone to more and more detail,

as we've allowed for more and more of those non-linear interactions and more and more details and more and more complexity, it turns out that those average heuristics that we started off with, they're still pretty valid. Yeah. Again, there must be a explanation for why we should have thought 40 years ago we'd be doing this well, right? Is there some ex post facto way of thinking that we were too worried about non-linearities or chaos? theory or something?

No, I mean, it's not that we don't think the chaos theory is valid. I mean, it totally is. And so, but it's a question of how much of the shift that we see in interannual temperatures or whatever measure that you want to look at is related to, you know, wherever you are on the, on the, on the, the attractor. where that attractor is in space, right? So there's effectively two things. I think some people get caught up by thinking that we're just on that

attractor and we're just going around and around and around and people can, you know, visualize the Lorentz butterfly and you say, okay, well, how can we ever know anything? But the climate problem is not working out where you are on the attractor. It's where that attractor is in face space. Yeah, okay. Right? And it turns out, I'm sorry, some overall kind of well-defined point.

Right. Yeah. Yeah. And so how much of the climate changes that we've seen are that attractor moving and how much of it is like kind of within the wheels. And it turns out that almost all of the change that we've seen is because that attractor has shifted,

not because we don't know quite where we are on that. Do you ever feel like you're drinking from a firehouse? Paycor's intelligent HR solution empowers leaders to turn down the pressure. Their unified platform includes payroll, talent management, compliance software, and a lot more, connecting you to the people, data, and expertise you need to drive long-term business results.

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That's hero.co. Per serving, not a low-calorie foods and products contain alu. See nutrition info on hero.com for sodium and sugar content. hand. Okay, when we compare, when we say that it has warmed, the average temperature has gone up, obviously in the past, we're using different methods to measure the temperature. For sure. So that's the thing. I mean, for you personally, like, what is the most relevant thing, us compared to 100 years ago or 1,000 years ago or 100,000 years ago? And what is the, I presume it gets less and less certain as you go into the past. Sure. So let's let's take that, that, that

view and go back in time. So we have great data back to 1979, which is really the beginning of the satellite here. I work for NASA. We're very proud of the satellites, the contribution the satellites have made, but they really make a step change in how much stuff. Right. And that, you know, that kind of started in the 1960s with the TIROS satellites. But anyway, but 1979 is really the starting point for comprehensive satellite measurements

of what's going. Okay. Before 1979, we have instrumental records on the ground, and that takes us back to, you know, the middle of the 19th century, right? So we had temperatures on boats, we had temperatures in weather stations, and, you know, and there's less and less as you go back in time. But you can get back to the mid-19th century without too much uncertainty. After that, it starts to get a little bit hokeyer, and you need to use alternative methods. And so people have been working on this for many, many decades. If you want high-resolution data, right, so you have data that tells you what's happening every year, every season,

you have to look at things like corals in the tropical areas. They have layers just like trees. Trees have layers. And so you can extract temperature signals from both of those caves, like, you know, stalactites. Stalekites, I think we use stalemites, not stentites, I mean. You know, they have layers. We can date those layers very precisely. We can go back even further.

But, yeah, I mean, it's spire. We have ice cores. The ice cores have annual layers until about 50,000 years ago, something like that you can count individual layers. So there is a lot of data there that comes from a lot of different parts of the world. But you're right. I mean, the further back you go, the more uncertain it gets. Balance that, though, the further back you go, the bigger the signal gets.

And so the signal to noise ratio for a lot of stuff that happened in the past is actually pretty comparable to what we can detect even the last hundred years. right. So you go back to, go back 20,000 years, right? So you're in Baltimore, 20,000 years ago. That was a tundra coastal plain where you are now. You would have been maybe

100 miles from the coast. And it would have been, you know, mammoths and various tundra-like things. Where I am, we would have still been under the ice sheet, maybe a kilometer of ice on Manhattan. And that ice sheet

obviously stretched from, oddly enough, Brooklyn, all the way to the Arctic Circle. And that was, that was, that was a huge climate difference from, from the, the late Holocene that we kind of grew up in as a society. And, and that was, that was about some, what audience would be talking to? Do I have to convert everything to Fahrenheit? No, you can't. No, you can be felt different. And we're going to trust the mindscape listeners out there to plug in if they need to.

Okay, okay. So, it was about 5 to 6 degrees Celsius colder. And we've warmed, you know, in the last 100 and so years, we've warmed about 1.5 degrees Celsius. So, you know, the uncertainty on that 1.5 degrees is about 1.2 degrees, right? So let's say, let's say a 10% noise compared to that signal. The uncertainty in the last glacial maximum temperatures is maybe a degree, right? So maybe it was six degrees, maybe it was four and a half degrees, six and a half degrees. Right.

So it's about a degree out of that five. So that's about a 20% error. So we can go back and we can still see those large signals. because they are large, right? So if we go back even further, we can go back to the Pleocene before the Quaternium, before the glaciation really kind of kicked in.

And we have reasonable estimates to the temperatures there is about three degrees warmer than pre-industrial. We can go back to the Cretaceous, even larger signals. You know, dinosaurs flying around everywhere. Theropods probably flying anyway. Dinosaurs everywhere.

And a warm. of maybe eight degrees Celsius above where we were in the free industrial. So we can see those things and we can understand them. And then, you know, then people will read our work as there's all sea climate changed before. And that's always a little bit of amusing because you then asked them, well, what's the sea level? What was the sea level like in the Cretaceous, do you think? And for our listeners, it was about.

100 meters higher than it is today. Something we would not like that half again, yes. No. But I know this is kind of obvious, but just so it's on the record here, the rate at which things are changing now, and for like you said, reasons we 100% or 98% understand, let's say, it has no analog in the historical fossil record. No, I know.

So we don't know quite how fast everything changed in the geological past, right? So that's one of the things that you lose is the ability to say, this took 20 years, this took 10 years. But compared to those last signals that I was talking about, so the warming out of the last ice age took 10,000 years to warm 5 degrees. And we've changed 1.5 degrees in the last 100. so that's

that's that's quite a bit faster um I mean I mean obviously there's there's there's one there's one thing that happened in the in the past that we're absolutely certain took no time at all effectively which was the the KT impact and you know we have we have records there of the day

of the day in the spring when that when that the asteroid hit, which is insane. But anyway, that was very fast, but obviously most things in Geoge Kvast didn't happen that quickly. Also, like with the sea level rise, that was pretty bad when that happened. You don't want to like say.

That was bad, yes. Sure. That was probably the worst day in the last 100 million years, I would say. True enough. And one of the things that I've learned from my very superficial reading about climate change and so forth is that it's not just the atmosphere, right? The water temperature is hugely important.

So can we get reliable estimates of what the water temperature was in the past? Yeah, so that's actually one of the real success stories of paleo climate has been able, has been the ability to pull that out. And there's a couple of things there that kind of tie back into some of things we've said already, which is how big is the single?

or how big is it not. One of the first things that people started looking at once they understood, you know, kind of post-war understanding of isotope system. People invented mass spectrometers, and they were able to, for the first time, measure the ratios of isotopes of different elements in different substances.

And one of the things that Harold Urie, who won the Nobel Prize for chemistry, for his work on this, he was looking at Deuterium and oxygen 18. So, etyterium is heavy, heavy hydrogen,

a stable isotope, right? Oxygen 18 is a stable isotope of oxygen. Most oxygen is oxygen 16. Most hydrogen is standard hydrogen. And it turns out that the ratio of those two things in water changes pretty dramatically.

Depending on whether the water evaporates, whether it condenses, in which pool it's in. And so it's a really good tracer of, you know, water moves around in the system. And then it turns out that it's, it's, uh, the fractionation is temperature, uh, dependent as well. Um, and so if you look at things that form from water, particularly shells, uh, carbonates, uh, you know, so that's, that's C-A-C-O-3, right? The O there comes from the water. And the ratio of oxygen, uh, 18 to oxygen 16 in that, in that oxygen there, um, uh,

actually reflects the water that the carbonate was formed in plus the temperature signal. And people took that in and they said, okay, well, let's see if we can find carbonate around the world. And in the 1950s and 60s, they were kind of really just kind of exploring the ocean. They didn't know about the mid-ocean ridges at that point. That was a new discovery. They would drop cords and then pick up mud. There was a boat here at Lamont Doherty. The goal was, anytime you stop for anything, take a core sample just in case.

And they ended up building this repository of data from the ocean's bottom, the mud in the ocean bottom. He's saying, well, what's that good for? And it turns out that there are little single-celled pheromina that have carbonate shells that exist through time. And you can just like in the ice cores, you can go back in time, and you can analyze that ratio. And it turns out that it doesn't matter where you are in the ocean. You see something that looks very similar. You see this kind of flat beer at the beginning. That's the Holocene.

It goes up. But temperature-wise, it goes down into the last actual maximum, bounces around a bit, pops up again 100,000 years earlier, goes back down, pops, you know, and then goes back in time. And as they put those things together, they started off with like about a million years worth of records. They found out, oh, everywhere you go is the same thing. And putting that together with the theory for why the glaciation's happened, which was developed by a physicist called Malankovic

who had some spare time while sitting in a Serbian jail in the 1920s to calculate all these things, He calculated all of the changes in how much of the sun's energy was coming in as a function of the wobbles in the earth. And that was, you know, this is before the days in mechanical calculation. It was very laborious. And it took him, you know, a number of years. But apparently he had the time to spare. A little time.

And that was that, you know, that was a hypothesis for. why the climate would change. And for a long time, it didn't seem to fit. For a long time, like the dating seemed wrong. But it turns out that it was the dating that was wrong. And when people got good at the dating, and then once they put together this stack of records from everywhere around the oceans, it was abundantly clear that he was spot on. And that there's a 100,000 year cycle, there's a 40,000 year cycle, there's a 19,000 year cycle, and put together those of, of pace, have been the pacemaker of the glacial periods and the glacial, interglacial variations for at least the last three million years.

So that was a huge triumph of that kind of empirical science. Yeah, so you emphasize that measuring these water temperatures at different points, different places around the globe, gives you a consistent story. And I'm presuming the story that you get is also somehow consistent with the atmospheric temperatures. Yes. So this is before anybody had the ice scores. So the ice scores kind of came in in the early 90s. So people were very excited that there had been some early ice school work in the 1980s, which kind of said, we can see something interesting there. But that wasn't really done to the level that was required until the 1990s. And there were a number of efforts in Greenland, and there were a few efforts in Antarctica.

that gave extremely complementary and coherent results. In Greenland, they go back one glacial cycles, so they go back 120,000 years, but in Antarctica, and now they've gone back almost a million years. You can see these ups and downs of the glacial cycles, and the greenhouse gases, right? That was the new thing that the Antarctic ice ice ice courts gave was the bubbles in the ice itself, we were able to measure how much greenhouse gas

there was in each of those bubbles, which is incredible, right? And so we get this, this, this, this, this, this, this, this, this, this, this, this, this, this, this, this beautiful record of the, the, the, the carbon dioxide, uh, which have gone hand in hand, uh, together, um, until, until, uh, until very recently over the last stream of because when you say the phrase greenhouse gases just so we're clear again with the audience that doesn't mean created by human beings necessarily there are gas no no no no no no I mean

so greenhouse gases in the rain are natural right so our planet is much warmer than it would be if it was a ball floating around in space without an atmosphere because of the the heat-trapping properties of small constituents in our atmosphere, but big deals in terms of the climate. So most of our atmosphere is made up of nitrogen, 78%, and I'll tell you a good story about why it's important to know that,

maybe later on. 21% oxygen, small smattering of argon things. It turns out that nitrogen and argon are almost totally inert with respect to infrared radiation. So they don't absorb or emit any, infrared radiation. So they absorb and emit at the higher frequencies. But there are some gases and other substances in the atmosphere that, that absorb in the infrared. And the infrared is important because that's the temperature that the planet is emitting. And so if you absorb

in the temperature that the planet is emitting, then you can make a difference. And so water vapor, which is triatomic H2O, carbon dioxide, triatomic, CO2, right? Methane, five atoms. All of these slightly more complex atoms have vibrational modes that absorb in the infrared. And that's what makes them greenhouse gases, and that's why they are so useful at keeping up the Earth's surface much warmer than otherwise would be. Okay, you've got to tell us an amusing story about why the abundance of nitrogen in the atmosphere is so important. So let me tell you, four decades of my life, right, I spent learning. totally obscure facts about science and the earth

and they never came in handy until one day I'm sitting in a bar and there's a as a cute girl just next to me at the bar and I had positioned myself so that I was being next to said cute girl

but I was trying to the bartender but anyway she turns around and asks me do you know the primary composition of air. And I said, yes. Yes, I do. And I saw, I said, oh, it's nitrogen, 78%. And at which point she kind of went white and then turned back to her conversation.

And it turns out that she had been trying to demonstrate to her conversational partner that nobody knows anything about science. And that this, I'm going to prove it by going to this random person, see you next to me, and they're not even going to know the first thing about the primary proposition. And that was the beginning of a big conversation and blah, blah, blah, blah. And, you know, she's now my wife. Oh, that's very good. I was hoping you didn't get away.

Yes, no, of course. Yes. Her white at first, but okay, she overcame back. Love bread, baked goods and pasta, but not the way they make you feel. What if I told you there are macro-friendly options that don't taste like sawdust and sadness, satisfying sandwiches, fully loaded bagels, noodles, noodles that can stand up to your favorite chunky sauces, all delicious. Craveworthy and smart, each serving of Hero Bread has up to 19 grams of protein and 32 grams of fiber and just 0 to 5 grams net carbs and zero grams sugar.

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Use code iHeart for 10% off. That's hero.co. Per serving, not a low-calorie foods and products contain allulose, see nutrition info on hero.com for sodium and sugar content. Okay, but one thing that I, one loose thread here is, I would kind of like to understand just a little bit better why the ratio of oxygen 18 isotopes to oxygen 16 isotopes depends on the temperature. You know, I'm literally just the dumb physicist here.

They're just isotopes. Why do they care where the temperature is? Well, so they don't. But you have to think about the water cycle on the planet. So where does water come to and go from in the atmosphere, right? It mostly evaporates in the subtropics, right? So kind of just north of the equator or just south of the equator. And when you evaporate water, it's much easier to evaporate lighter atoms.

Right? So when you evaporate water, you leave behind the oxygen at 18s and you have more oxygen 16th. So the ratio of 18 to 16 changes when you evaporate the water. Okay. And now that water, where does it go? Well, effectively, it kind of moves north and you've got this export of water vapor towards the high latitudes towards the poles. And as it gets further towards the poles, it gets colder. and as it gets colder, it rains, you know, more of that water

rains out. There's a lot more humidity in the tropics than there is in the mid-liditudes and certainly as there is in the poles. And so as you rain that water out, what rains out first? The heavy atoms, right? So the oxygen 18 gets more and more depleted. And so by the time

you get to the snow that's falling in Greenland, you have much less oxygen 18 than you started with. And it turns out that if it's a little bit warmer, you have a little bit more. And if it's a little bit colder, you have a little bit less. And so if you measure the oxygen 18 to oxygen 16 ratio in that snow,

that it becomes the ice that goes down through that ice core. When there's more oxygen 18, it was warmer. And when there was less oxygen 18, it was cooler. And you can calibrate that against the number of different other ways of doing it. And so you can actually end up with this paleo thermometer that is not perfect, but really quite good. Now, I'm sorry, keep going. Yeah, so, but that's not the only place where you're recording these isotopes, right? So I mentioned carbonate in four aminaferro, which are a small plankton, but also in cave records, caves are carbonate as well.

And it turns out that the, when you form carbonate, right, you take the oxygen. So carbonate is formed when you have, you know, carbon dioxide dissolves in water. It formed dissolved, deacrious carbon dioxide, carbonate, bicarbonate. And then when you want, if you're a creature or if you're a cave record or a stagite, you condense out the carbonate. But the oxygen came from the water. And as you do that, again, it's slightly easier to take the heavy oxygen and make it into a solid than it is otherwise. And that that's temperature dependent.

So there, if the temperature is high, you get a little bit more carbon 18 than you would do otherwise. So it's actually the opposite sense than in the ice cores. but in practice, it allows you, again, to go back in time and to derive a paleo thermometer that has other things going on, particularly, you know, the total amount of ice on land also changes the oxygen-18 content of the ocean. But effectively, it gives you a temperature sick. My kind of entry into climate modeling was really to try and simulate the interaction between those things. So how could you look at the paleo record and instead of trying to invert those records and try to work out when we're on, you know, could you forward model the kinds of things that you would be measuring?

So could you include the isotopes in the climate models so that when the climate changed, it would tell you what the isotope signal should be, both on the land and in the ice cores and in the ocean? And that was really my kind of my gateway drug into global climate modeling and the complexities of it. Because it turns out that that's actually a very big job. And I think it took us about eight years

to be able to do the first, coupled simulation of the full oxygen-18, the oxygen isotope climate record in a model. And I did not think it was going to take quite that long, but it did. And it worked out. You know, stories like that just remind me in a very nice, romantic way of how awesome science is. I mean, there's so many moving pieces in what you just talked about. And they all come down to the laws of nature being obeyed and they work and you can test them and they're robust. And we human beings can kind of mostly figure it out.

It never is easy to amaze me. Well, I don't know if we can mostly figure it out. We've been able to figure out some things. And the fact that we've been able to figure out anything is remarkable. But, you know, but a lot of times, you know, we spend our time looking underneath the street lamp and not. in the dark. And so it's not quite clear what we're not see. But where we can see things, we have been successful at doing so. And we continue to push, you know, that zone of illumination, if you like, about the natural system. Well, I have the luxury of being able to take the cosmic

view over which all of human history is very short. You actually have more urgent things going on. So you want the rate of progress to be a little bit faster. So let's, on that note, think about these models that we were talking about before. You know, everyone has probably seen some two-dimensional diagram of photons sitting in the atmosphere and being captured by

the greenhouse gases you already talked about. Take it that the models you get professionally paid to think about are a little bit more complicated than that. I mean, you give the audience like just a feeling of what are the elements that go into these. What do you, what do

what do the modelers have to keep juggling in their codes and their heads. Oh, yeah. So let's start at the source, right? So the sun is the source of 99% of the energy that comes through the system. So you start off with that. Well, what does that look like? Well, it's spectrally interesting, you know, so it's mostly in the visible, but there's a

component in the near infrared. There's a component in the UV. That comes in. How does it interact with the atmosphere? Well, the atmosphere is made up of lots of different things. as we mentioned water vapor and greenhouse gases and ozone and clouds and small particles which can be absorbing or reflective or scattering or a little bit of all of them. And so you have to track what happens to that ray of sun.

It has to be broken up into the spectral bands. It has to interact with all those different things, you know, one by one. there's a lot of what's called photolytic chemistry. So there are reactions that happen just because there are photons that come in and make that reaction happen, particularly in the stratosphere. And so you have to include that. And now you have to obviously, you need to keep track of, well, where is the sun? You know, and, you know, well, the Earth is rotating. Half a bit is in the dark.

Half of it is in the light. You have to keep track of where everything is. What happens at twilight? Something's a kind of chemistry-wise. The twilight is a very interesting time. You have to include all of those things. Okay, then now this sunlight kind of reaches the ground. Well, some of that reflects because there's snow.

Some of it gets absorbed because the ocean is dark or the land is not quite as darker. And then that temperature changes and now you have to go back up again. Okay, so everything down here is radiating in the infrared, depending on its temperature. I have to calculate that. then you have to do all those calculations going back again with what gets absorbed in the infrared. And so that could still include the clouds and could still include the atmospheric particles. It can still include the greenhouse gases. And finally, you know, some stuff gets out.

Okay, you say, okay. But like now, that's set up a whole bunch of different things inside. So, you know, those temperatures have set up gradients. They influence the winds. And so now we have to solve the equations of motion. Effectively, the oiler equations is a little bit of, Now, yeah, Stokes near the surface, but basically the oiler equations in the bulk of the atmosphere. But then that leads to upward motion and downward motion, and that leads to changes in the surface fluxes,

which brings water into the atmosphere, and then that water condenses. And okay, well, now that's a cloud. How does the cloud interact with all those little particles? And what's the chemistry on the cloud particles? What's going on inside the clouds? How does that change the reflection or the absorption? And so you just keep on going. And I haven't, you know, that's sounding complicated, but I haven't even started.

And so, so, you know, you try and do your best. You kind of chunk up the atmosphere so that you're not doing that, you know, with every tiny little point. You're doing it on a kind of column that is maybe, you know, 25 kilometers by 25 kilometers. You can go, you can do higher resolution, but it starts to take much more time. And that makes it a little bit easier. A lot of the physics is just vertical. So, you know, the radiation you can think of as just being a vertical process to very good order. Convection is also just a vertical process.

So there's a lot of things that you can do in the column that allows you to be quite efficient about how you solve the equations. So you can have each column like sits on a different processor. And so you can do lots of things at the same time. And then they interact via the winds and the waves and those kinds of things. Do you ever talk to astrophysicists who study stars or supernovae is relatively similar, sort of spherically symmetric but not quite dynamic and energy transport going on? Yeah, they have a, so in some ways it's more complicated, some ways it's simpler. So they have to deal with magneto-hydrodynamics, which we don't really have to worry about.

And it's a lot harder to get direct information from the middle of the sun than it is to get information from the middle of the atmosphere. atmosphere. So I think we have some advantages on Earth. I think probably that's why we're a little bit ahead of the game in terms of making useful prediction. You said that the sun is almost all of the energy input there. What are the other things that matter? I mean, when I drive my car, obviously if it's a gas guzzler, then that's something. But does the heat generated by the car matter? Does the heat generated by cities or for that matter, volcanoes matter to the budget? Not very much. So the heat generated by volcanoes is part of the whole geothermal flux, right? So that's generated effectively by there's a little bit of residual heat from, you know, the formation of the planet, but mostly it's generated by radioactive decay, right? So that's a, but that's a pretty small number. It's about, it's, it's about 0.05 watts to meter squared. and you're comparing that to the the average absorbed solar radiation of about 240 watts per meter squared. So it's three or four more, three or four orders of magnitude are too small to worry about.

But you do, I mean, you start, you do need to include it, right? Because that's, that's part of what sets the temperature profile underneath an ice sheet or in the soils, right? So you need to include that. It's a small term that changes the temperatures, you know, changes the desert ocean ridges and things like that as well. And go ahead. Yeah, and then there are, you mentioned the waste heat component. So we use about 15 terawatts of energy as a society.

So that's everything. You know, the renewables that we capture, the coal that we burn, the trees that we chop down, everything that we do. there, including bioenergy and the energy that we give out. I mean, but that's actually not a very large number either. So if you take the 15 terawatts, you divide it by the surface area of the planet, it's still not a very large number.

And the changes that we have put into the system because of the change in greenhouse gases, totally dominates that. So you can think of, you can assess that by thinking about, okay, here's the situation when we had the greenhouse gas levels in the past. Here's the situation now with the current day greenhouse gas levels. There's a lot more of them. It's a lot harder for the infrared energy to get out to space. And that means that if you just took like an instantaneous thing,

it didn't change anything else. What would be the change in energy at the top of the atmosphere by changing the greenhouse gases? It would be, well, the same amount of energy is coming in, but there's less going out. And so there's an energy imbalance. And so you would calculate that. And it turns out to be roughly two and a half watts per meter square.

So that's the forcing that we have put on the system in the last 100 years or so. Okay. And that's what's driving the warming. That's what's driving the climate changes. And that's quite a large number compared to the waste heat fluxes or any of those other things. Do you ever feel like you're drinking from a firehouse? Paycor's intelligent HR solution empowers leaders to turn down the pressure. Their unified platform includes payroll, talent management, compliance software, and a lot more,

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That's hero.co. Per serving, not a low-calorie foods and products contain alu. See nutrition info on hero. Hero.com for sodium and sugar content. Okay. And you did say one note that I have here I wanted to follow up on. You mentioned that most of the physics that was relevant here is vertical in the atmosphere. But in one of your article, as I read about the idea of teleconnections, these sort of non-linearities that are induced by currents in the air or the sea.

As soon as you just say that word and say that concept, I think that probably in the minds of the audience, the complexity of the problem sort of expands quite a bit when you start to take those things in the consideration. Right. I mean, and this is what you see on a, on a weather map, right? You're seeing those far fuel connections. You see if you look at a, if you look at a satellite picture of water vapor, right? And you see that a lot of times.

So if you Google atmospheric river, for instance, you'll see, you'll see water vapor pictures. And what you'll see is these, there's a lot of water vapor in the Toronto. and then you'll see these kind of rivers of water vapor kind of escaping out of the tropics and then intersecting with the continents, maybe in California, maybe in Europe, you know, and then dumping a huge amount of rain. But what you're seeing there is this kind of idea of a teleconnection, that something happening in the tropical Pacific is going to affect the weather a long, long way, many thousands of miles away from the tropical Pacific. And we have a pretty good empirical track record of like how that works. You know, so the El Niño, Laninia events, a bit of a sloshing of warm water along the equator in the tropical Pacific. If you have an El Niño, that's the warm phase.

So it's warm right next to South America. That tends to lead to wet periods in the American Southwest, It changes in the northeast Brazil, more fires and drought in Australia and Indonesia. And then when you have a landina, it's the opposite pattern, not quite the opposite, but close enough. And so these are patterns that, you know, big things moving in the tropics and then impacting, you know, what seems to be the more chaotic and further afield weather and climate elsewhere. And that's one of the reasons why one of the things that people struggle with is we talk about the global temperature, which we started talking about. But then the global temperature going up doesn't mean the temperature in every place simply goes up, right?

There's a patchiness. There's all sorts of these nonlinear effects. Is my impression correct that increased variance in weather events is part of global climate change? or is that just because our expectations are not quite being met in the same ways that they used to be? So there's more to that question than perhaps people realize.

So are we seeing greater variability or are we seeing, you know, variability and then that variability is shifting? Right. And, you know, so it's a statistical statement, right? So it's quite easy to see if there's a change in the mean, right? Because law of large numbers, I just take enough data and I can see whether there's a change in the mean. And there has been a change in the mean almost everywhere on Earth, right?

So over the last, even since the 1970s, it has warmed over something like 98% of the planet in a detectable way. There's a few places where it hasn't walked. There's a patch right to the south of Greenland, and there's a little band around the Southern Ocean near Antarctica. Unfortunately, nobody lives in either of those places. So anywhere that people live has walked. Now, then you say, okay, well, so has the variance changed? Well, as you might think, like to calculate the variance,

where you need to have an accurate picture of what that whole distribution is, and that needs a lot more data, right, to be able to say that with, with some confidence. And we don't quite have enough data to be able to say that the variance has increased. We have enough data to say that the distributions have shifted.

Yeah. Right? So are we getting as many cold, super cold days in St. Louis or in Baltimore No, we're not getting as many cold days. In fact, the climates in New York, in Baltimore and San Luis, have shifted by about a month in the seasonal cycle.

So what used to be, you know, March temperature, they now get in February. It used to be February, they're now getting in January. And the coldest month has now just disappeared. And so we're seeing much less of the cold outbreaks. and we're seeing much more warm-map rates. So if you look at the number of days above 90 degrees, number of days about 100 degrees, in general, these have all been increasing

over the last four to five decades. But this last year has been the worst. I mean, not just the worst because it's the most recent and therefore we're up there, but even compared to the models, my impression is, if we're hotter than we expected to be. That's true. And we have been,

in, you know, we were talking earlier on about like how surprising it is that we've learned anything. Yeah. And then, you know, perhaps we get a little bit complacent. Perhaps we then say, okay, well, you know, we know everything. And for the last 10 years or so, on the back of both those long-term trends, which we understand, and then that's sloshing in the tropical Pacific, the El Nino, Lanina, I think. I've been doing this.

There's a little college industry of people that kind of predict next year's temperature at the beginning of the year, right? So before you've had any data, just on the basis of what the trends are, and then whether you're in a Lanina or in an L'Dio. And for 10 years, that made us look extremely clever. Right? And we're going, okay, well, it's going to be a little. We call it's going to be a little.

But the trends are going to be up. you know, here's the chance of a new record temperature. And for 10 years that worked out. Until last year, last year it was a total bust, total bust, like way outside any of the uncertainties that you would add into such a prediction. And those uncertainties are based on the past data, like how good a prediction that would be given all the different things that have happened in the past. Right?

So you would think that the noise in the system, would be well sampled by just going back 100 years and seeing all the things that had happened. But it turns out, no, no, no. And we will weigh off. And we still don't know why. And that's a little disquieting. You know, is it because those empirical relationships that we derive, they're no longer any good because now we're in a new climate regime and, you know, the past is no longer a pretty, of the future, that would be a little bit concerning.

Or is there something else that's happened that I didn't include in that simple empirical thing? So there are things that could be happening, right? So, you know, the sun is going through its cycle and we're kind of on the upswing now towards a solar maximum. Is it that? Doesn't seem to be.

Is it changes in pollution in China or in shipping lanes because they've switched to cleaner fuels? Maybe. but the quantification of that has not matched that. Is it related to there was a quite interesting volcano that happened a couple of years ago, the Hungatonga-Hunga-Hpae volcano that put a very surprising amount of water vapor into the stratosphere? It increased the stratospheric water vapor by 10% on its own, just in a day.

It was an incredible eruption. It hit 56 kilometers, right? So that's over 40 miles into the atmosphere. And it was an underwater volcano. Like nuts. I mean, so that's very dramatic. Did that do it? So there's people calculating those things.

It doesn't quite seem to add up. So if you take all those different things and then you add up, okay, well, maybe it's a little bit of the weather here, a little bit of the weather there. It still doesn't quite add up. And so we ended up with records at the end of last year, August, September, October, November. that were, like, they were off the charts,

but then they were off the chance in how much they were off the charts, right? So they were breaking the records, but they were breaking the records by a record-breaking amount as well. So that's the kind of double, that's record-breaking squared, if you like. The second-order record-breaking.

And we don't really have a good answer for that yet. And I know that there's a moral work that's being done. You know, people are saying stuff. We're going to have a session on this. Hopefully, it's at the, at the big meeting in December. We're looking into it ourselves. But we don't really have a good idea.

And so that, that, as I said, is disquieting because, well, what does that mean for the future? So we're still, March just happened was also a record-breaking month. So we've had 10 months in a row of global record-breaking months. I think March might be the last one, maybe April, maybe a tad, but I think that this particular run is almost done. And we would anticipate, based on those cellar connections that we have derived from the empirical data, that as the El Nino has faded in the tropical Pacific, so that's kind of going away. and then by the summer it will be in a kind of neutral condition and it may even go to the cool condition by the end of the year

that those record-breaking temperatures will kind of come off that peak and will kind of will still be warm, we'll still have that, you know, 1.5 degree warming since the pre-industrial, but it won't be like bonkers. And we'll be back to being able to say, oh, well, we told you so because of the increases of the United Gasis. but right now it's a little bit tricky. But if I just want to understand,

if March only barely broke the record, that's compared to last March, which broke the record by a lot, right? So it's not like. No, so the record that it was breaking was March of 2016, which was the March following the last big Elvenio event, So normally what we expect is the El Nino peaks in December, January, and then like a couple of months later, we get the peak anomaly in the global green temperature, right?

So that these daily connections take a while to get out there. It doesn't happen at the speed of light. And so we expect, and all the times this has happened in the past, we expect the highest anomalies to happen in February and March following an El Nino event. And up until this year, until 2023, up until last year, that's always what happened. So the fact that the highest anomalies last year were in August, September and October, is like, that's never happened before. What's going on? But the fact that the anomalies are happening this year in February and March is actually very predictable.

And so we may be back to predictability land, but we are shaken in our confidence. And so, you know, when a model kind of fails at a multiple sigma level, then you have to go back to the model, right? Well, and just as a point of science, because I think it's very interesting, you mentioned empirical relations. By which I take it, you mean, you know, in science, sometimes we can start with the basics, with the periodic table or with atomic physics and electromagnetism and derive everything. Other times we just kind of look at what actually happened and notice that these two variables are correlated. And you're suggesting that previously reliable empirical correlations might have been off this last year. And that is, like you say, it's a little bit scary because that means they can get off more and more. Because they were never like, if it were founded in the fundamental laws of physics, you would figure, okay, they're going to come back.

They're going to be fine. But if it's empirical and we're not exactly sure what the derivation is, that changes in the underlying condition. can lead us places we don't want to go. That's absolutely right. And that ties back in with some of the things we were talking about before. You know, the temperature isotope relationships that people had first derived for the ice cores and for the things. It turns out they were wrong, right?

Because they were based on empirical data that was derived from spatial variations that we can see today. But really what you want is changes in time. And it turns out that the things that cause things to change in time are not the same things that cause them to change in space. And so empirical relationships that are derived from data that's available rather than the data that you need can indeed lead you to lead you astray. And it took us, I would say, 30 years to get to the point where we could

calibrate those paleo thermometers accurately using multiple methods, right, replication, and then like kind of doing this forward modeling of how things are actually happening based on more fundamental physics, perhaps not quite at the totally first principle level, but at a much, at a more complicated level than the empirical correlations that people would use up until there. Okay, so let's just get a handle on where we are now then. We had a scary year, which you don't quite understand yet, but there is an overall trend that we're still seeing. You've mentioned 1.5 degrees Celsius as, I mean, that's the number that I hear for the average amount of warming over less 100 years or so. Yeah, I mean, plus or minus 0.1.2,

we're not actually going to know when we cross that 1.5 threshold. There's not nobody, No, but there's no cosmic sign that says, you've done it now. Bing, Bing, Bing, Bing, Bing. No, so we're just going to, it may have happened. It may not happen for another 10 years. It's a little. What is your feeling about, okay, the next 10, 20, 50 years?

I know this is late in the podcast. We can be a little speculative now. So we're going to continue to warm on the aggregates because we are continuing to put carbon dioxide and other greenhouse gases into the atmosphere. until we get effectively to net zero, right? So no more addition of carbon dioxide to the atmosphere. Temperatures will continue to climb.

The less we put in, the slower that will be, but it will effectively, you know, if our best estimate of when global warming will stop is when we get to net zero. Yeah. We're away from that, right? You know, there are promising signs, right? So in the UK, they burnt less coal last year than any year since before 1800.

So that's pretty impressive. You know, per capita emissions in the US are down at like 1920s levels. That's pretty impressive too, right? You know, the rollout of renewable energy is going very, very well, you know, exponential, much half faster than expectations, etc. etc. But it isn't really displacing very much of the fossil fuel sourced energy.

And in fact, a lot of the people were even wanting to they're wanting to retire the fossil fuel plants but then they're being bought by Bitcoin miners who need an easy source of energy to make up stuff that is of no use to man or beast.

We can get new things to spend energy on. So that's Well, that is a problem. That is a problem. But anyway, so there are promising science, right? You know, there are promising technological things that are happening. Energy efficiencies is improving electric vehicles, not just Tesla's, but electric cargo bikes. So we, I'm a big fan of electric cargo bikes. It makes life in the city so much easier and more people should have those, right?

And that reduces the pressure on the roads, reduces pollution levels, a bit of a win-win all around. There are solutions that are coming out. You know, cities are more livable now than they were 20 years ago. Pollution levels are down. They're more walkable. There's a lot more, you know, space for pedestrians, that's like, etc. So my feelings on the matter, you know, really kind of depend on what I'm reading. in any particular day, right?

You know, I see an interview with the more paleo wings of various parties, and they're all into, oh, no, climate change isn't real, we should just burn everything, and then I see the worst-case scenario. And then I see, no, here, we did this solution in this small rural part of North Dakota. We, you know, Texas is building, you know, absolutely massive amounts of wind and solar. And I think at some point last week, it was 70% of their grid was, which this is Texas. That's impressive, right? They're not, they're not doing it for ideological reasons.

They're doing it for very practical reasons. And that's, that's great, right? So, you know, the cost estimates of these things keep going down and the money available to invest in these things keep going up. And you think, okay, we're on a good. We're not on the optimum path. We're not on the path that will prevent further damage and prevent the need for further adaptation. So we're going to have to be doing, we're going to have to be building client resilience. We're going to have to be adapting.

We're going to have to be mitigating. And you have to do all three. You can't adapt to an ever getting worse situation, right? It has to at some point stabilize. And you can't just mitigate because we're already seeing the impacts. and there's a lot of places that are not well adapted to even the climate we have now, which is not the climate we had 30 years ago, but they're certainly not going to be adapted to the climate we're going to have another 30 years.

So there's a lot of work to be done. I see a lot of people trying to push things in the right direction, try to improve those decisions that are being made. And so that gives me some, you know, yeah, I wouldn't say hope so much. But as we said, just depressed me quite as much as seeing people who know nothing, like spouting on about the climate change and how we need to drill, drill, baby drill. Do you have any optimism for very, at this moment, hypothetical, technological fixes for the atmosphere, like actively going in there and poking around in the atmosphere to lower the greenhouse effect?

So some of these are totally speculative. Some of them are based on real science that will work. But the problems that arise with these things are often not scientific. So let's take the most plausible thing that we could do, which we could put sulfates into the stratosphere, just as has happened with big volcanoes, like Mampson a tubo in 1991, and that will cool the atmosphere.

It will cool the service. There's no question, right? The stuff stays up there two, three years. There comes out. You have to put it back. But the problem with that as a solution is that you need to keep doing it, right? Until you get your emissions under control,

and it doesn't want to keep getting warmer anymore, you have to keep doing it. And if you keep increasing your emissions, then you have to increase the amount of stuff that you're doing. And then you say, well, how long do you need to keep doing that? And the answer is hundreds of years. And so you say, okay, well, so are there mechanisms in place that could ensure that this thing continued, regardless of wars, economic downturns, regional configurations, people like complaining,

sabotage, rura. And the answer is, no, there's no, there's no, there's, there's, there's, there's very, it's very hard for me to see how such a system would be resilient to the stuff that we're seeing every day, right? You know, the Iranians upset that it's not raining in Tehran,

but the, but it's raining in, uh, the, the, uh, the, the yellow river valley. the Indians upset the failure of the monsoon and blaming it on China who's running the you know these are you know these are not all rational people making rational decisions and when things happen people are not going to go back and say well let's just have a

solid scientific commission and work out exactly why this is going on unless you know that people are just going to start shooting at each other And so the chances that a system of solar radiation management, what they call it, is, will be robust to, like, the standard level geopolitical crises that we see every day seems entirely fancibly. And that means that if you start, you will stop. And when you stop, it's much, much worse, right? It's like all of that climate change in like a year. Right.

And, you know, we're having trouble dealing with it. when it's been over 100 years and now you're saying, okay, well, let's make it stop for a little bit. And then everything that we didn't have, we're just going to have all at once. And it's like, that's recipe for an absolute disaster. And so people that put their faith in that, I think are,

they're taking a much bigger risk than perhaps they relapse. Now, that's a very good point. I actually had not thought of it. I mean, as we said before, the changes to weather patterns over the earth are sort of, you know, multifaceted, et cetera. So maybe you could probably make an argument that anything that would make the overall climate better would make someone's climate worse. Well, yes, yes. And who decides, right? We don't have a global governing council to decide exactly who the winners and losers are going.

going to be. It's effectively, it's fought out, literally, it's fought out. And, you know, and losers are not usually very happy about that. And so I don't see it as a solution that is

going to lead us down the primrose path to peace and will prosperity. I did recently interview Hannah Ritchie. I don't know if you know her work. Oh, I do know. Yes. She has a new book out, arguing that Like, look, things are very bad, but we can't just say things are bad.

We also have to give people some hope. Otherwise, they stop fighting for it. I mean, do you have, you've been in the public sphere having these arguments for a long time. Do you have any, since we're near the end of the podcast, do you have any, like, words for the audience in terms of both the attitude they should take towards these challenges and how to maybe even do something at the small individual level to make things just a little bit better? All right, so let me make two points. You know, I don't think that as scientists, we are obligated to give people hope.

Like, that's not really our job. We're not motivational speakers. We're, you know, trying to tell people what is going on in the real world. And if you don't like it, well, the real world doesn't care. Nonetheless, right, you know, there are things that deride from the science that are, that people like to hear, right? One of the things that people would like to hear is the fact that if we get to net zero,

global warming will stop. If we got to net zero tomorrow, global warming would stabilize. I mean, the sea level will continue to rise a little bit, but slower and et cetera, et cetera, but the temperatures, which a lot of the weather extremes are associated with, would effectively stabilize.

And that means that any future change in temperatures, is actually related to future emissions, which means that we are in control. Which means that we as a society, and the rich emitting parts of that society are in control. And we have agency, which means that, no, it's not hopeless in that sense, right?

We have agency. Now, what do we do with our agents? How do we translate our feelings, our personal feelings and our personal actions into agency that makes a difference of the global scale, right? The key thing to remember is that we wear many hats,

right? We're consumers, sure, you know, we can make better decisions as consumers. We're commuters. We can make better decisions as commuters, or we can not commute at all. But we are often members

of our faith community. We are often members of the Parent Teacher Association. We can go to our town halls. We can go, we can go our city halls. We can vote in our local and state and federal elections. We can write letters to the editor. We can put comments on blogs. We can run a podcast. We can get our voice out there.

If you have something interesting to say, keep saying it and eventually people will hear you. our influence is not limited by our consumer choices right that would be bizarre I mean you think about Greta Thunberg whatever you think about her personally it's clear that a Swedish schoolgirl with no disposable income has had a massive global effect right now not everybody is going to be a Greta but we can find ways to multiply our voice, our opinion, our body of thought beyond, you know, just choosing to recycle some plastic bottles or something. But let me finish on one thing, which is kind of related to that same thing.

I said we wear multiple hats, right? and we've been talking about making predictions and, you know, doing science. And you might understand this. So where is the joy of being a scientist come from, right? It comes from observing things in the universe, encapsulating that in a theory, encapsulating it in some code, and then making predictions about things that you haven't already seen. And when you make those predictions and those predictions are skillful,

and you say, okay, I have a useful theory. I've done something great. I've taken the vast, inchoate mass of information that's sitting out there, and I've turned it into something useful. We're supposed to feel happy. We're supposed to find satisfaction in our job because we've made successful predictions. But when the predictions that you make suck, even if they're accurate, it's not joyful. It's not satisfying.

It brings me absolutely no joy to be able to tell people that the next decade is going to be warmer than the last decade and it was warmer than the decade before that. It gives me no joy to tell people that, oh, yeah, we're going to have another record-breaking year this year, next year, whenever. Because I'm not a such a bad. I'm a scientist, yes, but I'm also a person. And we live this dichotomy, you know, the people who are working in this area. And we're not the only scientists who work in a troubled system area. I mean, like, you look at Oppenheimer and you say, okay, oh, look, look what we've done? Oh, shit, what have we done?

It's a very, it actually runs through a lot of science, right? What do you do when you have predictions that work? but you don't want to see them come true. And, you know, that was encapsulated by Sherry Rowland, who won the Nobel Prize for the chemistry of ozone depletion. And he said exactly that in a New York article. What is the point of sitting around waiting for your predictions to come true? Right.

And so we don't, right? So in fact, right now the joy, the status. that one gets and being a scientist now is being able to tell people what is happening and having people act accordingly. And having them understand what it is that is happening in order to avoid our predictions being correct. Well, I hope that being on this episode can move you epsilon closer to feeling that feeling of accomplishment. Because I think that you really, look, I'll be, I'll be, I'll be. very honest. I have mixed feelings about talking about climate change because I know it's happening. The science is fascinating, but I very much feel that frustration, you know, the sort of sense

of banging your head against a wall that you alluded to. But I think this is going to energize people. I think this might just do it. I think this episode might eventually solve climate change. That's my guess. Yeah. Thanks so much for being on the Mindscape podcast. You're awesome. Thank you very much.