StarTalk Radio - The Science of Climate and Weather, with Kathy Sullivan

Episode Date: June 16, 2017

Neil Tyson explores the challenge of predicting weather and understanding climate, with ex-NOAA admin. Kathy Sullivan, co-host Scott Adsit, climate scientist Radley Horton, meteorologist Nick Gregory, paleoclimatologist Linda Sohl, astrobiologist David Grinspoon, Bill Nye.NOTE: StarTalk All-Access subscribers can listen to this entire episode commercial-free. Find out more at https://www.startalkradio.net/startalk-all-access/ Subscribe to SiriusXM Podcasts+ on Apple Podcasts to listen to new episodes ad-free and a whole week early.

Welcome to StarTalk, your place in the universe where science and pop culture collide. StarTalk begins right now. Welcome to the Hall of the Universe. I'm Neil deGrasse Tyson, your personal astrophysicist, and tonight we're going to be talking about the science of climate and weather. We're going to talk about tracking storms and measuring the atmosphere and how that will come in to predicting the safety and future of life on Earth. So let's do this.

Thank you. My co-host is actor Scott Agagsit. Scott, welcome. Hello. It's not your first rodeo here. No, we've spent many hours together. I'm very excited to give my ignorance a run for its money. And you were the voice of Big Hero 6. Well, yes, Baymax in Big Hero 6. Okay, so we also have Bradley Horton. Welcome from Columbia University. Thank you. Climate scientist. We're going to be heavily drawing on your expertise because we're featuring my interview with Kathy Sullivan,

who is the top dog at the National Oceanic and Atmospheric Administration, otherwise known as NOAA. NOAA. These people think about and worry about climate and weather like it's nobody's business. And so I've got my interview with her, but before she became head of Noah, she was a NASA astronaut. And I had to ask her about that. She was in the first class of female astronauts. So let's find out a little bit about that past. NASA's got like 30 astronauts left over from the Skylab Apollo era, reckons they need about

100 to make what they think the flight cycle will be with the shuttle. The shuttle was coming online. This is all about the shuttle now. So they put a big announcement. And a crew is six, seven people. That's right. Yeah, so this is boatloads. Boatloads.

Yes. And it's now the mid-70s, post-civil rights legislation. So this next generation astronaut class, how do you turn this into something that looks like America? Right. How do you make it credible to people who have maybe dreamt of it before and have never been allowable in your world? You've never let these kind of people in. Women go back home. Women, people of color, yeah, explicit.

Yeah, black person, get my bags. Yeah, we don't got this, right? So now you want to set up. You have to unlearn that. You've got to unlearn that. And so your ask or your invitation, when you say it, may well not sound very credible to those folks. And even once you're aboard, so we ended up being a class of 35 with six women. You were in the first class?

Yep. Six women, three African Americans, an Asian American. So ten people who, ten people the likes of whom had never appeared in the astronaut world. Never came close, not even a trace. Never even close. Yes, that's some pioneering stuff right there. Happened as late as the 80s, but we're glad it happened at all. And she was the first American woman to spacewalk.

She also was on the deploying mission for the Hubble Space Telescope. So I love me some of those astronauts, you know. If you put up my telescope, I'm good with that. But it's amazing that she was in such a diverse group in her first class, that first class. Yeah, it's interesting. They didn't start slowly in the first class. I think they knew they would be scrutinized carefully. But I would like to point out there's not one Romulan in that entire class. That's right. What we have also, just remember what's going on, is the Apollo era not only got us to the moon,

it got us to think about Earth in an important way. In 1970, we're still going to the moon, but the Environmental Protection Agency is signed into law, so too is the National Oceanographic and Atmospheric Administration, which cares about oceans and air. It's fun because to pronounce that is Noah, you know, which is kind of cute. Well, the very religious people are very happy about that. At least they get in there somehow. They get a piece of that action. And so NOAA, for the first time, you have an organization that combines the word ocean and the word atmosphere in the same phrasing, right?

That's right. I mean, these are totally coupled systems. You know, I think that was one of the messages when we first saw those iconic images from space that showed the Earth as one system, such a key part of the start of the environmental movement really so as you say it's this is a linked system it's linked in space right we can think about the large scale where we see waves in the atmosphere maybe the size of a continent we say waves you mean pockets of air yeah that move coherently right the jet stream with a ridge over one part of the USA that's warm.

And the location of those large scale waves in turn impacts the fine scale, right? It impacts whether you get the formation of a low pressure system and a storm with winds that then make their way down to the surface in an energy cascade, right? So there's that spatial connection of scales. And I think also a connection across different parts of the climate system too. Can. Can I ask, what separates a wave from what the wave is moving through? Is it just temperature of air? So I guess waves can form for... I was going to ask the same question. Yeah, was it waves can... It's a good thing I'm here. Yeah. Thank you. Thanks, Scott. You don't need me here at all. No, no, no. You got my back, Scott. I got your front this time. They can form for a variety of reasons.

I mean, one of the most basic features is the jet stream, which is largely driven by a temperature contrast between the warm equatorial regions that receive the most sunlight and the higher latitude polar regions. So you have these sort of stable formations, but then within that, these instabilities form and wave energy propagates to try to fill in some of those gaps. So you would have had no real global data on this were it not for NOAA. NOAA was critical, absolutely. And so here's Kathy Sullivan, former astronaut, head of NOAA.

And so I just asked her what NOAA is all about. And let's check out her answer. What is NO's all about? And let's check out our answer. What is Noah's mission? It really is to understand the Earth and how it works and translate that into useful information for society. Earth as a planet? Yep. We fly the country's operational weather satellites. Almost any picture you see on your evening news, the weather broadcast, is from a Noah satellite.

Nautical charting, we make all the country's nautical charts. The tide gauges and information that help ship pilots bring big container ships in safely. Then we also do ocean and coastal management like fisheries, marine mammals. Okay, so we've got atmosphere, ocean, land, and life. And life. Is there a system that I don't know about? No, basically, and there are chemical flows between that and the physics and chemistry that tie them all together. Earth systems.

Earth is a system of systems. But Radley, this concept of a system of systems, it seems to me is a modern idea in terms of systems engineering, right? Yeah, I think that's right. And we're learning about some of the feedbacks that can amplify an initial process. For example, in a hurricane, how you need an initial wind, which then stirs up the ocean, releasing heat, which can then make the wind stronger is one example.

So that's what you mean by feedback. Yeah. So one thing triggers another thing, and that other thing it triggers makes that first thing even more enhanced. Yeah, that'd be a positive feedback. Positive feedback. Right. And a negative feedback, it would just squash it out. Right.

Cool. So if you found a way to negative feedback a hurricane, you could dash them in the cradle. So you need your satellites. Absolutely. Without satellites, you're walking around doing this. More or less. That's what people did before there were satellites too, though, right? Before there were weathermen, what were the weathermen like? Like, my goat's facing Chicago, it's going to rain. My knees hurt this morning, everybody head to high ground. You got the rheumatism. Right.

I guess you're right. It wasn't that long ago when the biggest thing you would predict about the weather, just weather's going to rain on your picnic, and you only got that right half the time. And yeah, it was somebody feeling their joints or something. Yeah, well, farmers probably knew it better than anybody, right? They could probably learn what to look for. They live outside, yeah.

No, no, I'm sorry. I didn't mean literally. They spend more time outside than city people do. Yeah, and they depend on knowing how to predict how to raise their crops. Right. But they still use NOAA today. Yes. Yeah, they're not. No, well, they don't have to lick their crops. Right. But they still use NOAA today. Yes. Yeah, they're not...

No, well, they don't have to lick their fingers anymore. So when I or any of us think of weather, I don't think the first thing we think of is NOAA. We think of the National Weather Service. So I pose this question to Kathy Sullivan only to then learn that not only is she boss of NOAA, she's boss of the National Weather Service. Check it out. Under who does the National Weather Service fall?

Me. So that's a branch of NOAA? It's a branch of NOAA. I didn't know that. Yeah. It's a branch of NOAA. Okay. Yeah. And then we also have stewardship responses. So you are like queen of the weather weenies.

Oceans and atmosphere, man. Because a weather weenie, that's a whole kind of person. Yes, it is. Okay, who's got all the measuring devices in their backyard and the anemometer, whatever this thing is called. That would be us. Oh, my gosh. That would be us. Okay.

Well, in the same way that CNN does very well in their ratings when there's war, the Weather Channel does really well when there's extreme weather. Right. So people love watching extreme weather, the tornadoes, hover canes. It's mesmerizing. Absolutely. And I don't know why, because it's deadly. But maybe we just like deadly.

Like kids here like looking into the mouth of T-Rex. Yeah. And who doesn't love black holes, right, that will rip you to shreds. So maybe there's some morbid fascination we have as humans with things that could kill us, but we somehow keep a safe distance from. Or fascination with scale and power that we can't comprehend. Energy, yeah. Yeah. The manifestation of energy beyond our control. So, Radley, do you have any insights into people's fascination with extreme weather? Yeah, I think... First, can I ask first, the term weather weenie. Yeah.

No, that's a term of endearment. You didn't just make that up to humiliate her just now. Oh, no, no, that weather weenie, I thought that... Do people know about weather weenies? They're all shaking their head. Okay, I thought that was an endearing term. Does it bother you? I think I'll move on to the first part of the question.

No, whether we, you know, okay. I didn't mean it. I mean, it's kind of playfully sounds offensive, but if you're in the community of people who are. If you are a weenie, you can call someone else a weenie. Yes, thank you. All right. Thank you.

I'm a, yes thank you. All right. Thank you. I'm a, yes. That. So what's your insight into this fascination with deadly weather? Yeah, I think we heard a big part of it right there. As we're getting better in some ways at managing risk, planning for the future, as satellites improve, I think it's somewhat human nature to still be in awe of these things that can immediately disrupt.

At a safe distance. At a safe distance. Everything that can disrupt all of our best plans. And I think that clearly it's compelling to study some of these extreme events because if we can better understand what's going to happen, either in terms of predicting an individual storm or how the statistics of storms may change in the future, then we can reduce some of those risks. But I think there's another piece here, perhaps related, which is this, I think we should acknowledge this just sort of visceral element by which we're fascinated by these things,

thinking of tornado chasers. You know, there's a beauty to these extremes as well that maybe we need to connect with in some of our messaging too. So I think also, I think if I'm alone here, just let me know, but we're all looking forward to death. Once we let you know now. Let's have a talk.

No, I think the safe distance from something that will kill you is an interesting, who doesn't love sitting behind a picture window watching a thunderstorm unfold? Right. And maybe there's a way we can even leverage the idea that these extreme events are sort of exciting to people. As macabre as it is, is there a way for that to get some people to the table? When horrible things happen, like Hurricane Sandy, can there be a teaching moment afterward? Do you sometimes have potential to write after when people have seen the vulnerability,

when they're making decisions about whether to rebuild, how to use that information? Well, we're featuring my interview with Kathy Sullivan, former NASA astronaut and head of the National Oceanic and Atmospheric Administration, affectionately known as NOAA. Let's check it out. NOAA's job is, you know, take the pulse of the planet and transform those data into actionable, reliable, timely information. So I'm going to take satellite profiles of moisture and temperature in the atmosphere, and I'm going to transform that into a dynamic model of the weather

and tell you the likelihood of needing your raincoat in two days and how cold it's going to be. And over our lifetimes, the skill of doing that has gone from where you could sort of maybe trust the forecast for tomorrow and not so much day three to where you can swing some planning around day five, day seven. I've noticed this. It's been a day a decade. I've been very impressed.

It's been a day a decade. And it'll very impressed. It's been a day a decade. And it'll tell you the run of likely temperatures in the afternoon on Friday when you're looking on Monday. And it'll be in there. It's going to be in there. A day a decade increasing skill. I've noticed this. Good. I just want to say congratulations on that one.

So, Bradley, how is it we've gotten better at this? Is it just computing? It's partly computing, certainly. That enables us to go to finer spatial resolution, to pick up the finer scale items like storms. And some of it's just improved physical understanding. We've seen, we've got a longer record now of storms, of weather. It's still a blend of that prediction and model skill

and the expertise of individual forecasters. Can I thank you for giving the world your predictive passion rather than just like going to Vegas and using the same technology to count cards and predict roulette? Thank you. So sweet of you, Scott. I love science. But there are always going to be some fundamental limitations, whether sort of butterfly effect. So there are going to be ultimate sort of limits to predictability.

Butterfly effect, this is where chaos kicks in. By some small variation here, it explodes into something that you could not have accurately predicted. Because turning weather data into an accurate forecast, I mean, the meteorologists on TV have to do this all the time. Absolutely. And if they get it wrong, people get angry with them. Yeah, yeah.

But really, they should be getting angry with you. Absolutely. Yeah, because the weathermen on TV are meteorologists, but do they sit and do the math or do they just get reports and understand? I think they know enough of how to interpret the information that comes to them. Yeah. Some of it's maybe a local context for weather in the particular city that they reside in. Some of it's maybe decades of experience knowing when to trust the weather models and when maybe to sense intuitively that a certain system might

be unique and might not follow the traditional patterns. You know what we have? We have a video dispatch from an actual local news meteorologist to help us explain how they make their predictions happen. Let's check it out. Hello, Dr. Tyson. Nick Gregory here at the Fox 5 Weather Center in New York City. Coming up with a weather forecast with all the raw data we get from NOAA and other sources really is a science. Huge amounts of data that get plugged into various computer models, which then present a solution. We take that solution, apply our own knowledge of past weather events, and predict what we think is going to happen. For example, let's see how we would predict a potential blizzard. So we would start to look for those weather trends.

What would they be? Let's say high pressure ridging in from eastern Canada. We would then look to the computer models to see what type of jet stream pattern would be in play. And would this trough of low pressure be along the east coast, potentially with this jet stream riding up the eastern seaboard?

Pockets of energy then start moving across the country, this upper level energy that once it reaches the east coast, sets the potential for a storm to develop right in this location. That storm could then intensify and turn into a nor'easter and eventually track up along that jet stream track, leaving a swath of heavy snow alongside. So there you have it. Cool. I know this guy.

I mean, he's our local weather guy. It's nice you threw him some work. So to improve accuracy, it's not just an academic exercise. It matters. And what's the biggest reason why we need accurate disaster forecasts from you? Well, for one thing, it saves lives, right? I mean, if we can know that a hurricane is going to explosively gain in strength in advance, we can get people out of the way in time. For example, if we can better forecast tornadoes. It's also big business, right? If we can help inform people on when they should plant crops,

inform investments on how much money should be spent on heating fuels or something like that for a winter. So there's real economic implications and human lives at stake. Well, coming up next on StarTalk, we will answer your questions about the science of weather and climate on Earth and beyond when StarTalk returns. Welcome back to StarTalk. We're talking about Earth's sort of interconnected system of life, land, sea, and air, and how all of that conspires to give us our weather and our climate. And in this segment, it is now time for Cosmic Queries. Yes. Loving me Cosmic Queries.

This is where we answer questions from our fans, typically drawn from social media. And Scott, you've got these questions? I do. And if I can't answer them, I'm going to call lifelines. I'll do whatever I can to help this out. All right, go. All right, here we go. Amin Panwani from Tallahassee,

Florida, asks, as the Earth and Moon continue to pace themselves into a tidal lock, would the rotation of the Earth slow down? And if so, what would be the effects on our tide patterns? Ooh, I got this. You want me to take this?

You got it. Okay. So Earth has already tidally locked the moon. We have the effect of our gravity on it is stronger than the effect of its gravity on us, on our shape. So the moon only ever shows one face to us. That's why there's a near side of the moon and a far side of the moon. But there is a lot. So the moon only ever shows one face to us. That's why there's a near side of the moon and a far side of the moon. But there is no dark side of the moon. All sides of the moon get sunlight every month. Okay. Don't get angry about it. I am angry.

Pink Floyd put 10 years of my life in motion to correct their album title, Dark Side of the Moon. Just saying. Okay. So the moon is trying to tidally lock us. It's just not as good at it. So the moon is slowing us down ever so slightly. And we compensate for this by every now and then putting a leap second into the calendar. We've had some two dozen leap seconds put in ever since we've been able to measure the fact that the Moon is slowing us down at this rate. Ever since the early 1970s, we are compensating for this. It will take longer than the life expectancy of the Sun for the Moon to fully tidally lock the Earth.

So there you have it. Now, as earth slows down we have less of a rotational uh effect on storm manufacturing correct so do you have a like a rotation rate of the earth term in your modeling yes you do there's the coriolis effect which the coriolis effect yeah and so you can can you control how strong the Coriolis effect is? Yeah, when you do modeling simulations for other planets, that's a parameter that you can play with in a model. Okay, cool, cool.

Good one, yes. All right, number two. Petey Craigle from Milwaukee, Wisconsin asks, so Jupiter's storm, what has sustained it for so long and will it eventually stop? Ooh, I know it's been going since Galileo's time, but on StarTalk, we have ways of summoning knowledge from the universe that might not be present in this room. So let me conjure David Grinspoon. David, are you on video call? Hey,

David, there you go. Hey, how's it going, Neil? Hey. Someone is asking about Jupiter's red spot. How long has it been around? How ferocious is it? Is it going to keep going? So you're an expert. You work for the Planetary Science Institute. So what can you tell us about the red spot? Well, Jupiter has these giant storms.

The red spot's not the only one. It's just the biggest and most long-lived one. And interestingly, they do come and go over the years. spot's not the only one it's just the biggest and most long-lived one and interestingly they they do come and go over the years but the red spot has been there for at least uh 300 years and um it's interesting to wonder if it's gonna if it's gonna stick around these the other storms on jupiter we've seen that are almost that big Some of them come and go. But the red spot is a very stable storm system. And so far, it hasn't gone anywhere. And so, I don't know, maybe it's a permanent feature of the planet. Okay, so if you look at Jupiter through a telescope, it's actually

a strikingly patterned place in this upper atmosphere of bands and storms. Earth rotates once in 24 hours. Jupiter rotates once in like 10 hours. And it's way bigger than Earth. So it must have a staggering Coriolis force. That's right. Yeah, the winds on Jupiter are ferocious. And the Coriolis forces, as you've said, are really strong because not only is the rotation rate significantly faster than Earth,

but it has to make it around a heck of a lot farther because it's so huge. And so those forces are really strong, and that is part of, of course, what maintains these massive, massive, basically hurricane, massive hurricanes like the red spot. So can we hold you on in case the next question needs to go back to you too? Scott, what do you have? Ashton Norton wants to know, what's the most extreme climate in our solar system? So David, what do you have? The most extreme climate in our solar system? Venus. Venus has a surface temperature of almost 900 degrees Fahrenheit, which is all because of a massive greenhouse effect. Just like the greenhouse effect we hear

so much about on Earth that is getting a little uncomfortably strong right now, but an unbelievably strong greenhouse effect on Venus is what makes the climate there so extreme. So is Earth at risk of having a runaway greenhouse effect like Venus? Because Venus is commonly referred to as our sister planet. It's about the same size, about the same surface gravity. So why not think about it in other analogous ways? Yes, Earth is at risk of a runaway greenhouse in the very long run. In fact, in the very long run, it's almost inevitable that Earth will go the way of Venus.

Now if you're asking if there's a short-term threat because of the stuff we're putting in the atmosphere, imagine if we burned all the fossil fuels, every last ounce of coal, every last drop of oil, could we push Earth into a Venus-style runaway greenhouse? And there's a little bit of disagreement there, but I think the best models say, no, we're not in immediate danger of that. Of course, we don't want to try that experiment because long before we got to a Venus-like state, it would be uninhabitable for us. So David, thanks for calling in and helping us out on Cosmic Queries. Thank you. So we're talking about the science of weather, featuring my interview with the head of the National Oceanic and Atmospheric Administration, Kathy Sullivan.

That's America's weather and climate predicting anding Agency. And I asked her about one of the flashiest weather events she's ever seen, lightning. Let's check it out. Lightning, the science is still not quite nailed down. Love me some lightning. Who doesn't love lightning? Who doesn't love lightning? And the pattern of lightning and thunderstorms seems to change in ways that are diagnostic of a storm becoming a tornado. So there might be clues, early clues,

that this one's going to generate a tornado and that one won't. And, you know, ask any astronaut. One of the really magical sights is flying over a massive thunderstorm. Your astronaut. What's a magical sight? Yeah. Let me ask any. Okay, next time I have an astronaut, I'll ask them. No, I got one sitting right here.

You fly over a massive complex of thunderstorms. You know, on the ground when you're watching them, there's a bolt there, and a little while later there's a bolt there. You watch them from on top, and that cloud is like electrically active all the time. You see zippers of lightning racing. Because you see much more. You're seeing the whole complex. The whole complex. And it's like seeing a whole organism. Charlie Bolden said once, he got the greatest line. Probably the see much more. You're seeing the whole complex. And it's like seeing a whole organism.

Charlie Bolden said once, he got the greatest line. Probably the head of NASA. And one of my crewmates on a couple flights. We were looking at one of those one night. He said, isn't it like this is the light show accompanying some great concert and you wish you could hear the music? That's exactly right.

That's exactly right. So lightning, and some cool facts about lightning. As you may know, I don't know if you know this, the movement of electrons through the air catastrophically heats the air to 50,000 degrees Fahrenheit, which is about five times the temperature of the surface of the sun. And because it heats it catastrophically, it creates a shock wave. And there's a lot of deposited energy there. And I'm curious, Kathy said that tracking tornadoes

might be aided by tracking lightning. What's the connection between the two? There's some research suggesting that 15 or 20 minutes before tornadoes form, there's sometimes an increase in lightning activity and sort of the frequency of strikes that may be associated with what we call updrafts or downdrafts within severe storms. These are instances where you get more vertical motion, which can then feed on itself. And that wind shear is a critical factor in tornado formation. So the basic idea would be maybe, maybe in some instances, if you see an increase in lightning, could be indicative of a change in these vertical winds, which could give

you more wind shear. Maybe 15 or 20 minutes later, you're more likely because of that wind shear to get a circulation, stir up a tornado. Cool. And being hit by lightning is the standard metric of the rarity of something, right? You're more likely to be hit by lightning than bitten by a shark or bitten by a shark than hit by lightning. So we looked up the numbers. It's like about 50 people a year. And there was a guy, I think, in the Guinness Book who said, who was like hit most by lightning. I forgot the number. Was it seven or ten?

Because he survived all these lightnings. He said, somebody up there is looking after me. And I said, no. It's just the opposite. Somebody's trying to kill you and failing at it. So we're featuring my interview with Kathy Sullivan. She's head of the American agency that concerns itself with monitoring and predicting our climate and our weather. And I asked her, where are her people

just in the spectrum of assessing our changing climate? Let's check it out. Where we stand is on the data. We're the guys that collect the data, that archive the data so that national climate records are held by NOAA. All about the data. It's all about the data. This is what the data say. This is what... Let the record show she knows that data is a plural. It is. Okay. And is used in a sentence in just that way.

Yeah. Okay. If you take the data and you add basic physics and the physics of how adding extra gases to the atmosphere might affect the climate. We live on a greenhouse planet. We would not be here. Of course. We're not a natural resource.

We'd all be frozen over. Yeah. Yeah. The most abundant greenhouse gas in our atmosphere is water vapor. And that's not widely appreciated. I try to tell this every occasion. So you go to the desert where there's very little water vapor in the air. So it heats up in the daytime, and then it rapidly cools.

None of that heat is kept overnight because you don't have this blanket of insulation from moist air. And summertime temperatures here, when it's sticky hot and stays hot like all day and overnight, it's the moisture that holds it. But so can CO2. So does CO2. So does CO2 and bromine. I can say it, so does CO2. It does. Bromine, methane, bromine, and other compounds.

Well, when we take coal out of the ground or oil out of the ground and burn it, we're vaporizing solid CO2. It's been stored in a liquid or solid reservoir for millions or thousands of years. So to take us another step here, we've invited another guest, a Columbia colleague of yours. We have Linda Soule. Linda, welcome to StarTalk. Thank you, Neil. Yeah.

So Linda, you got the coolest job title ever. You are a paleoclimatologist. Yes, I am. Tell us what, I think I know what it is, but I want to hear you say it. I study climates of the past Earth. So, ancient climate. Really anything at any point in Earth's history that's not modern. So, all your life forms are dead, and all the weather that you're talking about has already happened.

Yes. Yes. Yes. So you guys are experts at climate, but from different angles. And we have this understanding, emergent understanding, of the role of CO2 in our atmosphere. And is there much agreement in these communities about what it is, where it's going, and why? Yes, I believe so. It's really a pretty fundamental issue at the heart of all of this. We've known since the 1850s that there are these things called greenhouse gases in the atmosphere.

Carbon dioxide is an important one. We've known that those greenhouse gases warm the atmosphere, and if you have more greenhouse gas, you warm the atmosphere more. And we have the data that shows the changing levels of CO2 with time, since about 1850 or so, caused by human activity. So that includes things like fossil fuel burning, but it can also include some other activities. But with CO2 increasing, there really is no question that climate has to change to accommodate that push, that forcing. So basically, tell us exactly what CO2 does in the atmosphere. So CO2 is an interesting molecule that's sort of shaped like a V.

And it has the ability to vibrate. A V, so carbon is in the middle. Carbon is in the middle and oxygen is on either end. And it has the ability to vibrate. A V, so carbon is in the middle. Carbon is in the middle and oxygen's on either end. Okay. And it has the ability. Yeah, it's like that. And it has the ability to absorb heat and re-emit it. And the more molecules that we have like this, the more the atmosphere is capable of capturing that heat and then re-emitting it back down toward the Earth. It's the blanket that keeps us warm. And normally that's a benign thing. But when we have more CO2, then perhaps it might be comfortable.

We start to see some changes. In fact, without it, Earth would be really cold. Yes, it would. Like uncomfortably cold. Yes, it would. And in fact, without greenhouse gases, Earth might completely freeze over. You don't even have to get rid of greenhouse gases altogether to get to a state where Earth can be frozen over. So we have an image of this. It's called Snowball Earth.

That would be bad if that happened. Yeah, that's a reasonable representation. Don't say that. Say this is an exact... Don't tell me it's reasonable, because this is nasty. But this would thrill fans of Frozen, I think. So around two billion years or so ago, we think that this was more or less what Earth might have looked like from space.

Ice. Mm-hmm. Was this from an absence of greenhouse gases? So it would have been from a severe drop in the amount of greenhouse gases in the atmosphere, yes. You dropped your greenhouse gases. What dropped them? We think that it's highly probable

that microorganisms that were doing photosynthesis, you know, for the first time in Earth history, generating lots of oxygen, actually changed the chemistry of the atmosphere and basically destroyed a strong greenhouse gas effect that had been keeping the planet warm despite the fact that the sun was much dimmer. Ooh, so this is before there was any complex life on Earth. This is two billion years ago. So basically microbes swimming in the ocean. That's it.

Doing the backstroke. Singing, let it go. Well, you study, what's this period, the Pliocene? So the Pliocene is one of the warm periods that we study. It is not the warmest in Earth history, but it's the most recent one in Earth history where CO2 levels in the atmosphere were pretty much where they are right now, around 400 ppm. So you have data on what this could be, what this is? Yes, we do. So what...

Go on. So in the world of the Pliocene, you know, roughly 3 million years ago or so, with 400 ppm CO2 in the atmosphere... Parts per million. Parts per million. We know that the global average temperature was between 2 and 3 degrees Celsius warmer than modern. We had

much smaller ice sheets on Greenland and Antarctica. And to go along with that, sea levels were probably at least 25 meters higher than today. That's about 81 feet higher. So if you can imagine a world where, for example, Florida is completely flooded out and a lot of the coastal areas of what would become the United States later are also flooded, that's the Pliocene world. So what is not widely appreciated is why sea levels rise. And because I don't think we connect the fact that you have water that is on land and not moving, and that's called glaciers or ice. You start melting those puppies, they just dribble into the ocean and the ocean levels rise. And it's hard to conceive that there's that much water that's not in the ocean that could be. So what are we doing about this?

Well, we're starting to see some heartening signs, I would say. I mean, the two things we can really do are to mitigate the greenhouse gas emissions, right, to change our society, and also to prepare for some of these climate changes that are already locked in. Because as Linda just indicated, even if greenhouse gas concentrations could stabilize where they are today, we're locked into a lot of additional sea level rise. Basically, there's all this momentum, climate momentum that we still haven't seen. A lot of CO2 gets absorbed into the ocean and comes out later. That's right.

Yeah, and also a lot of these molecules stay in the atmosphere for 100 years or more. Sounds like a big liberal lie to me. Quit lying to us. So, but Linda, it sounds like you've got the answers because you've seen major climactic shift that happened by natural causes that could clue us into what we are creating by unnatural causes. So what's your best warning you can give us? We need to find a way to cap the emissions that we are currently creating as a civilization so that we can basically come to a stopping point in change that, while it's not going to be fun or easy for civilization as we know it, is still adaptable. So if we're 400 parts per million now, what was it in 1850, approximately? In 1850, it was about 285.

So we've increased it by at least 50%. Yes, yes. In 150 years. Yes. And for Earth to do that on its own would take how long? Well the closest comparable change is from the time of the last glacial maximum. So that's the most recent ice age, the furthest advance of the ice across North America and Europe. That was about 21,000 years ago. And CO2 in the atmosphere then was about 180 parts per million. So from 21,000 years ago to the year 1850, by natural processes alone, Earth increased

CO2 in the atmosphere by about 100 parts per million. We have well exceeded that in just over 160 years through human activity. And we're blowing past, so it's not like we're stabilized at 400 parts. No, we're still blowing. We're blowing past this.

Yes. Okay, so the problem is not what the level is. The problem is the rate at which it's changing and the ability of civilization to respond to it. So something that many people get confused about, and that's the difference between climate and weather. And when we think of weather, we think of is it going to rain, what's the temperature, humidity, precipitation of any kind, atmospheric pressure. These are the things in the here and the now. And then the climate is sort of the average of this.

And why should we believe that you can predict the future of climate if you can't predict the weather more than five days from now? Is that a fair question? It's a very fair question, I think, but they are quite different questions. When we're talking about climate, as you just said,

it's the long-term statistics. There's random natural variability from one week to the next, one year to the next that's very difficult to predict. But the idea with climate is that the statistics sort of balance out over time. So if you're planning for the future, if you're trying to decide how high a seawall should be, what levels of heat extremes to plan for for the future. We can say with a lot of confidence that statistics are changing and we should plan for it, even if we can't tell you in the weather sense exactly what day you're going to get that heat extreme in the year, say, 2024.

So it's one is you can say that climate is what you expect and weather is what you get. But there are people, you know, who will deny climate change, for one thing. And I'm wondering if the evidence over the course of the last two decades is backing up that prediction. I'd say for the most part it is. I mean, there are challenges when you look at it. Ten years or 20 years seems like a very long time. But at those timescales, there actually is a fair amount of natural variability, which is largely unpredictable. As we go to longer timescales,

30 years, 40 years, and especially in the future as greenhouse gas concentrations, the source of so much of this projected warming, as those go up, the statistics are really going to change in a way where we can say there's going to be more heat waves, more frequent coastal flooding of the type that we've seen during severe weather events. So you can't necessarily see all the things just by looking at the last 10 or 20 years. But if you take a longer view, there's a lot we're already seeing that we've predicted. Sea level rise, the idea that the atmosphere would warm, that some of the ice sheets would retreat, the upper ocean would warm. A lot of those predictions that we get

from greenhouse gas projections are playing out in the long term, even if you don't always see them if you just look at the last 10 years where there can be a lot of that variability you talked about. Okay. So when we come back,

Bill Nye, the science guy, gives his thoughts on the science of climate change when StarTalk returns. Welcome back to StarTalk. We're talking about the climate of our planet and forces that could render it uninhabitable for life as we know it. For America's chief climate top dog, Kathy Sullivan, head of NOAA, the National Oceanic and Atmospheric Administration, this is all about sharing the love and the data. Let's check it out.

So the world uses our data? The world does use our data, and we, about two-thirds of the data we use in our weather forecasting come from other countries. Every country exchanges weather data, you know, free, no charge. You guys don't fight each other? No. Man, no one can do a weather forecast without the whole globe. You measure your bits, I'll measure mine. You actually cooperate with Russia?

We do. What a concept. And this goes back to the olden days where it was guys slinging instruments in the air and all handheld. And the data have continued to be shared even when countries have been at war. It's just like cruised through real political tensions and big hostilities because it's just too critical. That's a profound fact. It is. And, you know, that's why you can do a weather forecast.

You have to sample the entire globe. As Carl Sagan once said, air molecules don't carry passports. They don't. They go wherever the hell they want. They do. And the one that was over you yesterday is over me now. So we've got to exchange the data. Take it back.

So, you know, something important is going on when politics can't even get in the way of it. So how does this play into the Paris Agreement that we hear so much about? Okay, so the Paris Agreement, what was special that happened in December of 2015 was that the countries of the world came together and formally pledged to limit the amount of warming to two degrees Celsius, about three and a half degrees Fahrenheit, above that pre-industrial climate of 1850, before carbon dioxide levels had gone up by about 40%. And this is critically important because the further we push the climate system, the bigger the potential for surprises. We know we're going to see sea level rise. We know we're going to see more frequent flooding of our coastal cities, more heat waves, more heavy rain events, and paradoxically, more droughts as well. And because it's Paris,

probably a lot more mistresses. That kind of agreement. Is that how they roll over in Paris, right? So this requires a level of international participation that may be without precedent. That's right. And where are we in this, the United States? Well, the United States per capita remains the biggest emitter of fossil fuels. We've

been surpassed. USA. Number one. So basically all the countries, given the scale of the challenge though, all the countries of the world are going to have to dramatically reduce their emissions. But it's fair to say that historically the U.S. has been responsible for more greenhouse gas emissions than any other country. Remember, they last in the atmosphere 100 years. But per capita is one thing, and I get that. But we have one-fourth the population that China does. So are we the number one greenhouse gas? No, China is the top overall emitter.

And as we go out further into the future, some of the other countries with very large populations, such as India, could potentially surpass us as well. But maybe as we see some cooperation from countries, it starts to send a signal to the private sector, for example, that this is the way that the wind is blowing, in a sense. We just have to hope that this uptake of renewable energies, and we need other technology too, right? Battery storage, for example, new transformers. We have to hope that that societal tipping point that can get us those changes happens fast enough relative to the potential rapid shifts in climate and societal impacts, changes in agriculture and things like that. So it's a huge, it's a race against the clock. So before we wrap, I want to catch up with my good friend Bill Nye, the science guy, to get his take on the planet's changing climate.

Let's check it out. When scientists look at the ice in places like Siberia, Antarctica, or Greenland, they can tell that the world's getting warmer. Now, I've been to Greenland. I've been to the East Greenland Ice Core Research Project. I've seen them pull the ice right out of the ice sheet. And what scientists do is measure the neutrons in the water. They look at the atmosphere that's trapped in little bubbles between the tines of the snowflakes. They look at tree rings and the growth rates. They look at pictures from outer space.

They've collated all these data, and they produced a graph, which looks about like this, where the world has been about the same temperature for several thousand years. But in the last 250 years, since humans started burning coal and oil like crazy, the world has gotten warmer, faster and faster.

Everybody, it's not just that the world's getting warmer. What the hockey stick shows us is the speed, it's the rate that the world's getting warmer. These are the facts. So we're gonna have to change the way we live. Now look, at this point, you might expect some hilarious hockey pun, like, nature's gonna put us in the penalty box, or nature's to give us a

slap shot right to the face. But this is serious. Climate change is the most serious problem humans face. We've got to get to work. Back to you, Neil. So you know what I wonder? When I look back in the 1960s, we were going to the moon. One of the most famous images ever was Earthrise over the lunar landscape. And there was Earth as nature intended you to see it. Before then, there wasn't much illustrations of Earth with clouds. Draw Earth, you draw like the ball, oceans, land, and that's it. Clouds was like something else. Now you will never see someone illustrate Earth without clouds.

The atmosphere entered our understanding of what Earth is. It's not just the solid ball. It's the air we breathe as well. And you realize the air on Earth is about as thick as the skin is to an apple. Our atmosphere is to Earth. So I claim that what happened then, over those years we were going to the moon, is that we went to the moon to explore the moon and we discovered Earth for the first time that's why the Environmental Protection Agency is founded 1970 Noah 1970 Earth Day 1970 you know some the planet doesn't give a

rat's ass about us it really doesn't It'll be here long after we are extinct. So the real question is, can we be good shepherds of this planet? The very planet that's keeping us alive without any fear that we will be the source of our own demise. For me, space brings us that cosmic perspective. A cosmic perspective that may save us from ourselves. Ladies and gentlemen, you've been watching StarTalk. And I've been your host, Neil deGrasse Tyson. And as always, I bid you to keep looking up.