 And welcome, Mark. Welcome back, as the case may be. It's my pleasure to introduce tonight's speaker, Professor James White, who's a fellow of the Institute for Arctic and Alpine Research at the University of Colorado at Boulder. If you were with us last night, I'm sure you enjoyed his talk, Sustainability, Climate Change in You, more for the general audience. When we invited Jim, we also asked him to do a more technical talk on his research, which is what we have planned for tonight. Professor White's areas of research include modeling, the global carbon cycle, development of techniques for measuring ice-to-tilt ratios and atmospheric gases, reconstructions of paleo-environmental conditions, and tracing of groundwater flow and return. He's been a member of several deep ice corp projects, ice corp projects in Greenland and Antarctica. Ice corp research has helped to show that large climate changes tend to occur in the natural system as abrupt and rapid shifts rather than slow and gradual adjustments to changing external conditions. Tonight he's going to tell us about his work in his, about this work in his talk, Ice Corp stories of rough climate change in the future sea level. Please help me greet Professor White. Thank you, Chuck. I'd like to thank everyone. I've met a bunch of you over the last two days, a day and a half, that didn't happen. I remember. It's been a lot of fun. Chuck, I thank all of you for inviting me to come here and speak and spend some time with you. You've got a bunch of really fantastic students here, and you've got a wonderful place to do this now. So, thank you. And hopefully this evening we can have some fun with this topic and move on. A new button, I found out. Did you find it on your phone? So, I want to ask you to give more of a technical talk. I sort of try to balance technical here because we can go deep into these stabilized Tokyo chemistry. Would you like to do that? No. I've got at least one member of the audience who says, it's not good, but I will try to get a little more into it than what I did last night. But if at any point along the way, I say something and you go, hold on, that's not making a phone. Raise your hand and we'll stop for a moment and back up and make sure that everybody's on the same page. So, I work in ice cores. I started working in ice cores a long time ago, 30 years ago. I'm not really fond of the cold. So, I haven't actually been really happy the last day and a half. But I have to tell you, even colds are in boulders, believe it or not, when I left. And we spent some good time today talking about, ironically, a good friend of mine, who's also on the polar research board with me, Jennifer Francis has a theory that a lot of the cold outbreaks are actually the result of global warming. That's called the Arctic Paradox. I'm not even going to try to explain it. Put that back here. I thought I'd start with some pictures. So, what does it like to be in ice cores night? We travel from Schenectady, New York, to, this is a picture of Kangaroo Swack, Greenland. That's the topography around here. Not any trees. There were trees, but they were all going to cut down. So, it's pretty barren. It's tundra. There's muskox. Muskox are basically large, sort of like hairy cattle with bad attitude. They do have a bad attitude. They do not want to mess with them. They leave behind wonderful fur that you can make absolutely fantastic sweaters out of, and they don't want to get anywhere near them to get that fur off. Pick it off, horses and stuff like that. Anyway, this is a C-130, the New York Air National Guard does the following. You see the skis here. When it lands on a pavement, the skis are up a little bit. When we land on snow, these skis come down, and we can land and take off. It's always exciting to land and take off these things, because one of the interesting reasons is that if you've ever been skiing... I was about to say, if you've ever been skiing, where am I? You know that skiing on dry or powdery snow, not only do you get better downhill, but also a better cross-country. What we've been seeing in Greenland over the last 20 years is more and more wet conditions. And these planes have trouble. So, we actually fly at night, and night is the... the sun comes up, it goes down in the spring, it's not really night, but it does get darker, it does get cooler during this sort of traditional nighttime knowledge. We've started to fly and do our work at night. This is what it's like on the inside of the plane. You'll notice a couple things. Everybody has earplugs. There is sound insulation inside of the military aircraft. It is loud. It is so loud that if you wanted to have a conversation saying this that somebody couldn't do it anyway. So, it doesn't really bother you that there's no movie. There's no... there's no service. The disc canvassing thing back here is hiding the loop. But you've got to do something that, you know, you pretty much are out there with everybody else. I have no clue what this guy is doing right now. It looks like he's having fun. This is what it's like flying into a camp. You see the... the runway is running like this. We have to... This is the... This is where the drilling's done out here underneath the snow. This was our home called the DELM. I'll show you more pictures of that. You see tents out here. This is where we live. This is another place where we live. We have to spread everything out because the way the snow blows. If you put everything close together, you will get big drifts. And you can't do that. And so, what we do is we tense space everything out. That means you're walking. You're already in, you know, the highest of the days, maybe negative 20s. You're already pounding out calories just to stay warm. And you've got to walk on top of that. And we do work below the snow surface because when it does warm up, we don't want to mess with the ice core. So, what we do is we dig into the snow, cover it over with a roof, and then work down the snow. The mean annual temperature is what you'd be working in. The mean annual temperature is about negative 30 degrees. See, it doesn't really matter at that point. It would see you're having cold. This is the, on the ground here, the, cool, the, at the plane land, they open up the back of it. And they do what's called a cargo combat offload. So, there's some cargo. They just unhook the pallets on the floor there. And everybody gets out of the way. And they call the pilot gun the plane. The pilot gun the plane and the pallets right out the back. And that's when you hope that you factor scientific equipment really well. Because you have to be able to get, any scientific equipment you bring out there unless you're specifically able to fragile it, and made it into a combat offload in which case it could get bounced around. We've had some equipment broken. This is a typical day. The wind blows. You can have total light-out conditions at the surface and then look straight up and you see the loose guy. Just because of wind. This is, as you know, you live in a place that's flat. And when the wind starts cranking, there's really nothing that stops it. Here we don't even have the trees to break it up. So there's no boundary layer of all of this wind. That's probably the one thing that drives you most crazy after a while, is you just, you know, would you quit blowing? It won't. There are some pretty days in that the flag here is indicating that the wind is still blowing. This is what it's like under the surface. This was a place called North Crip. We've been here for about three years at this point. You see the roots we put over the hole. You also see that after a while it fails. And so this was actually kind of cruel here for the entire last season and the roots get wet and we're calling people to get in and out. The OSHA does not exist. Anyway, you sort of see that the, it's not a very good picture, but the drill is lying in here. The drill is this long string of stuff that goes in and out, pulling the drill, ice core all day long. Wet stuff on the board to drill through. Pretty sparkly. We don't really jazz this up very much. We're here to get ice core done. We really enjoy ourselves. Here's a picture of an ice core that's just kind of light coming through. It's kind of a cool shot. This is an ice core. This is the bottom of the North Crip ice core. And this is when we started to get rocked. This is the first sunny of, you've gotten to the bottom of the ice shape and you start to get rocks and pebbles in there from the bottom of the ice. Typically, we stop there. If there's any electrical engineers in the room, we know that when we make contact with the bed, suddenly we have ground. We've never had four. And so all your electrons in the room go, whew! So you really don't want to get ground unless you have something to have. This picture is here for several reasons. One is, you get, and we talked about this with the students, one of the cool things is you can contact all these clothing manufacturers and say, would you either give me for free or a deep discount, somebody would just stop. So we contact North Face, Go Light, and all sorts of companies. And what you get is what they can't sell. Which I have on right here. We have a nice red pants with a blue jacket. And the purple hat, my wife particularly hates the purple hat, but I particularly love the purple hat. She's been with me for about 30 years now. I will not give her the purple hat. The other thing that this points out is that everybody gets the lousy jobs. So my job this day, and I spent about eight hours doing it, was these are actually fuel barrels. We're going to have that fuel in them that we would refuel. A twin-autor to a small aircraft would come in and out. And there's a hand crank that you fill them up, but you can't get that last little bit out of the barrel with the hand crank. And so somebody, being me, I unscrew them and dump all the little bits into one barrel. And so I spent the day soaked in jet fuel aid. Despite the fact that this is not beer. It is jet fuel. And so I'm just sitting here enjoying my day. So everybody gets the lousy jobs. It's my day to do it particularly. You know, emptying the latrine of the other jobs we don't want. And getting out is always exciting. So these are something called jatoes, a gen-assisted takeoff. And if the plane is having trouble getting off the ice because it's overloaded, the pilot has a couple of options. One is to offload some of the weight to the plane. The other is to try these things, to get the plane off. They don't like to offload things off the plane because typically we want to get the ice core out or the cargo out or something important after you're off. But there's always this debate inside the airplane. When you try, I've been on airplanes that have tried 10 or 15 times to get off. And after about 10 tries, you get this kind of sinking feeling in the middle of your stomach because the pilot is going to either try this or he's going to start offloading weight. And you are weighting. And so I frequently, three or four times in my career I've been thrown off of an airplane. The next one's coming in about three weeks. So you were ready to leave, you're ready to go home, but uh-oh, back we go. We're going to spend three weeks on the ice core. Planes come about once every three to six weeks or something like that. So it's not like every day you get a flight, ready to stand and stuff. Anyway, this is a good shot here. On the other hand, flying with the Air Force is fantastic. They are wonderful pilots. They're extremely good. They once took us down through a fjord, literally through a fjord. I don't think we've probably had more than 100 feet on the other side of the wingtip going down this valley. And the pilot's tip, he goes, you know, we're going to let you look out the window. And of course, no one's in the seat belt. You're just hanging on to the car. It's a totally different way of flying. I did tell the students, I wasn't going to tell you this story, but I did tell the students, it's really funny. The TSA of the military is kind of humorous. You walk up to the little, the machine that checks you for metal, metal effect, and you're asked to take your guns, knives, and bombs out of your pockets. And so, unload, you know, guns, knives, and explosives, because we use explosives and then you go through the metal detector and then you reach back around and you pick up your guns. Stick them back in your pocket, and you go on here. And you just want to know that you've got a gun or an ice and it explodes. They don't really care that you've got it, just want to know that. Because you are not the only one on the plane with a gun or an ice. Anyway, all right, so let's talk a little bit about flying. The last ice core project we just finished up in Greenland called Neen, or the North Neen project, which is named after the Neen. The Neen is a, an old pollen, palaeology term for the last interglacial group. It's about 120,000 to 140,000 years ago. It's the last time that the climate on the planet was as warm as that one was warmer than today. And it is our closest analogy in time to a warmer climate. We have not successfully recovered ice from that time period in Greenland because it's right down at the bottom of the ice sheet. And I'll show you the reason why, but when you get to the bottom of the ice sheet, all sorts of funky things happen. In one location we had melting going on. It's actually like that north-west side. We had melting going on and we actually drilled in and did water at the base of the ice sheet. And there's no, water's not uncommon at the base of the ice sheet. There's enough ice that accumulates to the point where you get pressure melting at the bottom. There's actually lakes underneath that arc. I was on a caddy committee that basically tried to lay out ground walls for going into these environments that really have, we haven't did in for 30, 40 million to a year or something like that. It took a long time to fit in. Anyway, a couple of cool things happened in the, I'll show you the science from there, but one of the things that happened was in 2012, all of Greenland had a melting event on the 12th of July. And we don't, we can actually see melt events in ice cores. You can see that because when the ice melts, the ice that's formed is clear, not bubbly at all. So we can actually see these melt events. And the melt events at this location, when we are, I'm sorry this is not marked, we're way up here at this site. Very, very rare melt events at this site. You know maybe a couple of them during the last several thousand. But this was, and we've been seeing more and more melting, but this is the first time we're actually seeing melting all over the place. I wasn't up there, but the folks who were there took this picture. I've been on top of the ice sheet many, many times for about 30 years. I've never seen a rain boat because it's in the rain. On top, they actually have a rain at this location. So they're on top of the ice sheet at an elevation of around 13,000 feet. And it's raining on them in July. Which is pretty darn amazing, anyway. Excuse me. What was the temperature at that time? During the daytime? Yes. It was about freezing slightly above freezing. Just slightly. Probably about one or two degrees to get something like that. It didn't get, wasn't up in the bombing category. It's actually miserable. No, seriously, when it's cold and dry, you notice, I mean, it's actually not so bad you can handle that. But when it's cold and wet, it's when it gets miserable. And this is, I never liked being up there when it's cold and wet. So why are we going to look at the last interglacial period? A couple of reasons. One is, it was warmer than today by a couple of degrees. That is, I pointed out the analogy for the future. But the other important reason why we were after this location is we wanted to see what the ice sheet looked like during the last interglacial period. And one of the ways to do that is to recover an ice core that goes through the last interglacial period. And to get an idea of, you know, was it a lower ice sheet? Was it a bigger ice sheet? We didn't think it was going to be a bigger ice sheet. We thought it would be a lower ice sheet. This is, so we've been talking about this all day with students, but there's two ways that we look at climate in the past. One is through paleo-climate. The other is through model, what I call model world. The model is getting together and figuring out, this is what I think happened. So the modelers have a whole bunch of models they've been running like five or six hundred iterations of this model. This is what they think the Greenland ice sheet looked like during the last interglacial period. This is what their model was telling them. Given the ocean was warm and given the atmosphere was warmer. Today, this isn't a big ice sheet. So there's a divide in here that's perhaps no ice at all. There's a southern part and then northern part. And in their world, Greenland melted to the tune of about four meters where the sea level being added to the ocean. And we know that the sea level was about higher by four to six meters at that time. So multiply by three if you want to translate. So the sort of conventional wisdom had always been that Greenland being much warmer was melting and contributing most of this sea level. And that was really the fundamental hypothesis that we wanted to test was indeed Greenland the spot where this was coming from. We found a couple of things. One is I'll explain what's on the screen here here. So I apologize. Paleo-climatologists run time from the left to the right and the right to the left. And we're just sort of ambidextrous that way. So I'm going to challenge you. In this particular one, time runs from here today back in time on 120,000. We also don't use negative numbers. We're not mathematicians. We can't struggle with the concept that time would go positive or negative. Anyway, here we are today. This is the our interglacial period, the Holocene. You can see it's a nice flat, relatively flat, long period of time. We talked about this last night. We actually enjoyed a very stable climate for about 13,000 years, which has been very beneficial for us between being free and able to develop agriculture and large societies around the climate that really hasn't been all that variable. I go back into the glacial period here 20,000 years ago to about 100,000 to 80,000 years ago. And you see a couple of things here that are important. I'll come back to these, but you see these ups and downs. And when I first started in ice core science, there was a lot of debate about what these things were. And one of the first things that I did as a postdoc was we measured how fast this last what's called the under dryness is cold-grade how fast that ended. And I'll talk more about that when we're talking about rough climate change. But you see this is a pretty angry climate. And then we come through a period here and then we come back out into the last interglacial period. This is actually the record that we got. I'll show you how we got this. But there's a couple of things you can see. One is that this is considerably warmer than here. It's higher up. And this is measured in a parameter that I'll come back to in a second. It's the OACO 16 ratio super-monitor that we use in ice core. So here's the change in temperature blown up this little piece right here goes right here. So here's temperature coming up crosses actually zeros today crosses today and then it goes warmer. It goes warmer by about eight degrees Celsius. During that time Greenville was about eight degrees Celsius or this location was about eight degrees Celsius. It's warmer than it is today. Now there's a couple of ways that you can get warmer. One is it can actually be warmer. The second is that the ice could have been much lower because if the ice sheet is lower you're farther down in the atmosphere and it's warmer as you go down in the atmosphere. By now this is roughly 13,000 feet and so it's cold because it's cold and because you're at 13,000 feet. So one of the reasons why it's been warmer is because the ice sheet was mower. The third reason is we could be fooled by the fact that there was more summertime snow here. So this particular thermometer only functions when it's snowed. This is the OACO 16 ratio of the ice itself and so unlike thermometers that just sit out there and record 24-7 this one only records when it's snowed. So if it snowed more in summertime we would get a bias warmer temperature. If it snowed more in wintertime we'd get a bias colder temperature. So we attacked all of those possibilities in this paper that we wrote. The surface elevation we can get from a couple of measurements that we make the simplest one but the one that we kind of struggle at the time is just measuring the total amount of air that's in an ice form. And as you go when you go up in the atmosphere you have less atmosphere and so that was that was probably our best measure. Now it's not perfect we argue about that but we had a couple of ways to attack that and so this is what we think the elevation history was it was a little bit lower than today and somewhere around 124,000 years it was approximately the same as today it's actually higher by a couple hundred years. So it only went down by maybe a hundred to 200 years relative to today. So that's important so it was warmer considerably warmer but the elevation didn't change too much. Now what that says it was actually hotter at that time we could see that this part of the ice core is full of melt ice this part of the ice core has very few like I said one or two predominant melt ice this the enium in the last year it was shot full of melt ice it becomes much warmer clearly much warmer at that time. So we had a couple minutes a little bit of a conundrum was green and really 8 degrees warmer this actually is supported by a whole bunch of other data from the Arctic that argues that the Arctic was as much as 6, 7, 8 degrees warmer than today at that time it was warmer because of the sun of the Earth-Sun relationship we had more insulation more solar energy in the summertime than we do today greenhouse gases were probably the same so those of you who sat through last night it wasn't greenhouse gas it was solar so you can have all sorts of things in this particular one but the surface elevation didn't change that much it was told us that the ice sheet up in that area not in that negative way it's actually pretty much the same as it is today it's a pretty big ice sheet now what I showed you is the result let me show you how we got to the result because we had to get to it by a lot of machinations one of the things that we found is that at the bottom of this ice sheet there's a whole bunch of small topographic features that are probably triggering fully in the ice the ice is moving along from the left to right here and as it moves along and goes over these bumps and wiggles you begin to get sort of waves from so those of you who sat through geology you've seen these wonderful features in rocks the same features you find in ice well you can't really see them very much now this is a radio anchor so this is a we we make noise at the surface and then we have to see how the sound waves bounce off as you would see this has improved tremendously that technology has improved tremendously for seeing what's at the bottom of the ice sheet and it unfortunately improved tremendously from the time we chose where to go to the time we actually got the ice core so when we chose where the ice core was we couldn't tell if these kind of features existed near the bottom of the ice sheet the technology wasn't good enough now later on they told us hey it looks like they may be folding here I'm sorry we've already built the cam we've already drilled the ice core now you can tell it should be folding indeed there was folding there and this on the right hand side is the actual record we measured with depth and on the left hand side is actually how we put it back together in time so this is what I just showed you in that other figure 30,000 years ago showing cold it gets warmer and it gets warmer these two pieces in here are actually in version now you might ask can you tell they're in version well there's a lot we can measure in the ice core and one of the most important things that we can measure in ice cores which make ice core sort of unique from a paleo climate point of view is they contain atmosphere they contain gases in the atmosphere it's about 10% air now because the composition of the atmosphere varies and because the atmosphere is very well mixed we can go to a place like Antarctica where we can get this section of ice without any question of folding we know it's stratigraphically intact and we can get the record of methane of CO2 of nitrous oxide of the isotopes of all of these things so we can get unbiased records of what the atmosphere can go to Greenland and we can say what do we see there and what we saw was that the only way that this section made sense is if it was inverted because the methane and the methane isotopes were varying over that time period and the atmosphere doesn't lie it's because the atmosphere is pretty well mixed what you see in Antarctica ought to be very very close to what you see in Greenland and so we had a way of knowing what the truth was and then unfolding the ice that we saw in our geology majors you know you gotta do this anyway gotta figure out how to unfold this stuff well we in the ice core business were just learning how to do this now I'm gonna try my movie play we gotta have one failure this is a little a movie that was made by a company in Denmark and what they did was they had the ice flow they took it over a couple photographic features and then as the now we can colorize it but what we think we saw on the bottom 100 meters of the ice you get these folds that form that are stripped off the top the top pieces get torn off and then you end up with pieces that are flipped over on their side and here comes our drill you like this neutral geology? so that's what we think happened at this location and we got good evidence the show that that was the case but this was kind of this was the first time that we we had folded ice core and we were able to unfold this just recently in nature magazine so this is the lessons that we learned from you have already talked about this we can reconstruct the what we call precipitation weighted temperatures so this whole business of summer winter is working in the background somewhere shows a maximum of 8 degrees to be warm then today 124 126000 years ago the insulation was higher so we expected to be warmer but this was warmer than we were in the Arctic to support this and interestingly Greenland did not contribute more than two years of sea level rise so in order for us to be as high as we were at that location Greenland could not the Greenland ice could not have been terribly different than it is today the southern part was probably much smaller but the northern part was as robust as it is today and you might ask well how is that that possible well one reason is you've got a lot of ocean out there the Arctic Ocean particularly in summertime so you've got a lot of source water for feeding Greenland snow and so probably what we think happened was that the ice sheet didn't really change that much because it traded warmth which was helping to melt it for additional snowfall coming in off the Arctic Ocean that's the theory that we have right now but it's relatively clear to us that there's no way we can reconstruct the ice sheet and get more than about two meters of sea level rise so that begs the question where did the rest of the sea level rise come from and ironically having worked our tails off in Greenland we ended up focusing our conclusions on Antarctica so Antarctica is the other spot where you've got lots of ice and the other spot where you get sea level rise so I'm sure these slides by site are still alive there is one of the things we do know about our planet is a very simple relationship between sea level and temperature when we have a warmer planet we have a colder planet sea level drop and for two great basic reasons one is water expands a minute warmer and contracts when it's colder and also land ice melts and there's a very powerful reflectivity feedback that actually begins to melt the ice to get to more heat so sea level temperature is easily one of the most robust paleo-climate relationships we plot those two things this is an example now time is going in the other way so here's today going back 400,000 years and this is sea level I didn't plot the temperature record on the top of here the temperature record looks pretty much exactly the same here's today our interglacial period here's the last interglacial period there's previous interglacial period marked with sea level at those times you can see a couple of things one is you know our sea level today is just sort of a random number relative to the sea level we age in the past 400,000 years ago sea level is about 20 meters higher than today 300,000 years ago it was about the same if you go back 200,000 years ago it was about 2 meters higher than today and if you go back as I pointed out it's about 5 to 4 to 6 5 to 8 people give different numbers higher than today if you go back 100,000 years ago so sea level is dynamic on the planet so we know that and we know it has to be coming from you really our sea level has got to come from Greenland and or Antarctica that's the only place where you can get that kind of dynamic this is 20 meters sea level that those words are actually written on the ice sheets it's a long time but we did it but we only got about 6 feet out of Greenland during the last interglacial period so the rest of it comes from our good friends for the south now this raises some interesting points about the Antarctic ice sheets the Antarctic ice sheet is actually two ice sheets this is the bedrock topography right if you look at the actual ice it's pretty boring big white flat thing right there's east Antarctica which is this piece over here where most of the bedrock is well above sea level so it's sort of a classic ice sheet there's the western side which encompasses all this area over here and with the exception of some islands down here most of this is below sea level and you can't read the scale here but this is 10,000 feet but that's 10,000 feet below sea level that's so it's not just below sea level the bottom of the ice sheet it will below sea level the bottom of the ice sheet so the western Antarctic ice sheet is what we call a marine ice sheet where the bedrock is well below sea level marine ice sheets are interesting creatures because the bedrock is below sea level now why it makes them interesting it makes them interesting because of something called the grounding line the glaciologist is talking about the grounding line it's a spot where the ice is coming out towards the ocean in this case forms a nice little ice shelf floats out in the ocean but this is where the ice friction against the rock holds the ice so that it can back up behind you so you can't really grow ice flows very well you can't really grow big ice sheets unless you've got some point in the system that stops the ice from flowing and allows the pressure to back up behind you so that's the grounding line look at from the side what this looks like is here's your ice shelf here's the ocean and you can see this is well below sea level over here so you can start here's our grounding line so you can start to see the grounding line is really critical if the grounding line disappears then you've got basically water to get back up underneath here and you lose your control on the ice it can actually start flowing out into the ocean here's an example of what we think happens in this situation here we have the ice shelf coming out cold water underneath here that's not doing a whole lot of work in melting ice as the ocean water warms up it can penetrate up underneath here then you start really eroding ice so in terms of the biggest control on what we think now on the on the pinning of these ice sheets is not air temperature it's water temperature so what the ocean does in terms of the ocean circulation what the ocean does in terms of the warmth and the southern oceans are warming up and so we get warmer and warmer water coming in and eroding this critical little grounding line now this is important because we'll back up for a second as I pointed out if we lose this frictional spot ice can start to flow much faster in Greenland there's only a couple of places where you can flush ice out from the ice sheet into the ocean and you can see those from the satellite you can see the the big ice streams in Yachtville South of New York the big ice streams that go north I'll show you what that looks like you can see these things on satellite pictures in Antarctica the western part of Antarctica I'll back up here to make this point there's a big window right here a big window right here and a big window right here where there's really not much stopping the Antarctic ice sheet loses its pinning line there you have hundreds of miles of open throat basically and ice just starts flowing out and we are glaciologists are at a point now this is a wonderful message for you students we don't know how fast you can put this stuff out the models simply you know don't have enough information in order to be able to calculate well just how fast an article can dump the ice line into the ocean rising at a rate where we'll hit three feet by the end of this century pretty conservatively rates have been a factor of 10, 20, 30 higher in the past and if the Antarctic ice sheet starts to lose its pinning point and starts to shed ice it could easily raise sea level rise rates by more than a factor in the past easily by more than a factor now this is important because three feet in a century is such that most of us are like okay I'll talk again about Miami again but you know Miami's kind of toast by 2100 Miami's not a functional city anymore but 100 years is a long time even the folks in Miami don't get excited about 100 years if it's happening 10 times faster then 100 years shrinks down to a couple of decades a couple of decades is the timeframe on which we build and finance homes on which we build and finance air conditioning systems in which we build and finance sewage treatment plants that becomes a societally interesting number maybe 20 years sounds like a lot to you if you're 21, 22 years old but trust me when you sign that mortgage one of these days for 30 years home you know you get an impression of what 30 years apply if you build up if you buy a home and you expect within 30 years a home to be no longer functional because C-levels risen and takes your home away then you know this is bad so up again see where it works on me this is a little animation from NASA just showing the speed so the reds here are fast flowing ice and the the blues are slower flowing ice but you see this very large area here on the rostae shelf very rapidly flowing ice this is these are actually reconstructed ocean currents using satellite observations the area that we're really interested in today happens to be this area out here called Pine Island so along here you have very rapidly flowing ice in here today because you have very warm ocean currents that are getting up underneath here the other side of the rostae fissioner ice shelf also has a very very rapidly flowing ice I had to show this because NASA is thin but low easier tax dollars putting it together question? yeah if if if sea levels or if if sea temperatures are warming we get enough to force some of that ice out you know if we really flush a lot of ice out that in turn could cool the water yeah but how how is it all how does it all play on? well if you take a look at the satellite ocean it's there's not nearly enough ice to battle there's a lot of heat mass question? yeah I don't quite get the idea of the ground and why yeah this is a physics problem when you think about the coefficient of static friction right that's great enough over an area it's going to be I think about the friction of large over an area and not over a sea level it is well it's basically what it is it's a line that follows the topographic features when the ice comes up and it bumps up against it if it wasn't there the ice would be flowing through past its way so it's basically a topographic feature that is stopping the ice sheet from keeping going out into the ocean so it's a bump it's a bump and actually the ice sheet feeds the bump because any crud that accumulates on the ice sheet then when it comes down and melts it dumps it and it's a graduating process the friction keeps adding crud here so what's happening today is not only is it getting warmer but with sea level rising it's actually lifting up that little chunk of the ice as well so both of those things have is mostly warm ice okay when you say the ice sheet is moving rapidly how fast is it ice moves at you know 40, 50, 60 meters a year there are places where you just saw that video you just set out a row of flags across some of those large areas you know 50 miles across and in a matter of a couple of days you can see that the ones in the middle are moving much faster than the ones in the edge but physically really quick it's quick you can see it sorry so the question is not if sea level will rise in a warmer climate but really we're focusing in on these two questions how fast and how far so how fast can I we don't know what's within today and the real question is will it be fast enough for us as societies to really care about that because right now at a hundred years lifetime from Miami we don't really share so much if it's a 20-year lifetime from Miami I think people might begin to share and the second question is how far how far will sea level rise and Antarctica goes how high up does sea level rise it's not going to reach three feet by 2100 to stop there so I showed you this last night sea level rising today by a about a meter by the end of the century it's not going to stop there and this is without West Antarctica collapsing so no one none of the three feet one meter does not include any problems with Antarctica this is what I showed last night Miami really doesn't have much of a future beyond the end of this century this is the city that I pointed out last night you can go visit the bottom boats you can go carpet fishing you can go you can ask a simple question in terms of that how far the simple question you can ask is what was the climate like last time we had roughly 400 million in the atmosphere thinking okay under that condition what happened you know was West Antarctica gone the answer was yes West Antarctica was gone so how high was sea level and the playa scene about three million years ago is the last time we think that sea would be 400 parts we're 390 something today we can't go back a long way of time to find the earth today it's about 30 degrees Fahrenheit warmer in the arc for trees right at the edge of the arc circle at that time there were certainly less sea ice and there was less land ice and sea level was pretty robustly somewhere in the neighborhood of 20 to 25 meters higher than today so what does 20 to 25 meters of sea level look like and by the way from a kind of climate point of view is that if we let the system sit for a long enough period of time you know maybe several hundred years it will go up roughly 20 to 25 meters higher sea level that sort of is a simple answer to the question how high would it go we don't know there's no mechanism we can think of that stops it and says okay I'm sorry this time around because human beings are here only going to go up 10 years we'll let the science decide no number of plots that look like this but this is an instructive this is the global main temperature plotted against sea level and what you can see is again on our planet there's been a whole bunch more points on here on our planet you've got a very robust relationship between when you have a warmer planet you've got a higher sea level when you've got a colder planet you've got a lower colder planet you've got a lower sea level about 20,000 years ago it was about 11 degrees colder about 120 meters lower sea level here's the pricing point I just showed you I just talked about this is when Antarctica's totally melted out it's about 80 meters higher than today and this is the last interglacial period here this by the way is the intergovernmental panel on climate change forecast for change for 2100 and there's no reason that we can see why this is just going to go this way and not this way this point is actually not on the line it's a tiny bit above the line so it's really a question of time you've got to let the system have time and it will eventually so we expect if indeed we warm right around this area we expected to be up around the supply scene level in terms of the sea level in the future so let's have some fun it's relatively grim so let's have some fun so what happens whether we're all over 20 meters of sea level rise all right thank you Google because you can go in and do this actually we have got enough good photographic material thank you US Geological Survey and thank you Google this is Delaware with 20 meters of sea level rise Delaware is no longer with us now good students of Chris Davis and all of us what was the first state of the Union Delaware signed first on their license plate it says first state of the there's beauty in here first in first out you gotta have some humor involved in this here's Delaware we're down to 49 Delaware is the first one to exit first one in it's also where the first Swedish colony in America was founded in the 1600s and thank goodness they moved west you know thank goodness they settled around here the we talked about this today with students number one agency the number one US federal agency when it comes to spending on climate change is not the National Science Foundation it's not NOAA it's not NASA it's the Department of Defense it's our Pentagon because they know that stuff like this they know that there will be refugees and they know that these things don't sort themselves out they don't like it so they spend a lot of money doing similar planning for this kind of situation this is the bottom of the jet there's hundreds of millions of people here and this country over here which is India is not going to welcome them with open arms and this country over here is not going to welcome them with open arms they don't particularly like each other climate refugees are a reality for our future India has already built a fence to keep the bottom of the jet you're lucky that there's some interesting spots and this is the Great Valley of California there's all sorts of tomato strawberries all sorts of stuff underwater under this area 20 meters of sea level so you can guarantee that we're going to build a dam right there in the Martinez area you can know we've got a dam coming right here by the way so when I give I talk in Colorado I'm going to live in Colorado want to be interesting features of this area down in here this is Oakland's a pretty low-lying area and so Oakland, Alameda County Stadium which is where the Oakland Raiders is gone under water when I give the talk to a bunch of broadcasts fans everybody so here's Florida here's Louisiana this breaks my heart because I I love the food there I love the culture there but those folks have got to move hopefully they take the food and culture there here's Florida Florida so we are spending billions of dollars fixing the Everglades today billions of dollars fixing the Everglades today and it's Oakland's I mean the Everglades are toast by the end of this century and they're definitely going to be underwater in the future here's your key key piece of information what's really important right here Disney World World you were close I'll give you a beat Disney World is right here turns out they were 20 meters to see them arrive the Disney princess can sail right up here or down the Jacksonville River right to the Magic Kingdom right so Disney's going to make out like a man Disney's going to talk about it well it's not a thing but why you know Disney's got to figure it out what I'd like to tell my students is follow the money who makes out like a band that are climate change Disney who's behind climate change? how did you come to your own? alright so I'm going to spend about I'm sorry I took a few much time I'll spend about two minutes talking about climate change and I'm going to take questions before climate change I'll just move on here when I was a graduate student our view of climate change was driven by changes in the sun and changes in the sun are slow thousands of years you take for the sun to change there's a recession to the orbit of liquidity to the orbit eccentricity to the orbit and this she says in words what I'm trying to say in general solar changes are slow thousands of years so when I was a graduate student I learned about climate change was that it took thousands of years to go from the glacial state to the interrelational state it took thousands of years to go from the interrelational state to the glacial state because it's all driven by the sun Jim did you get that okay so now we got interested in this when I was a postdoc some very smart people in Copenhagen said let's measure this core down here which has a very high accumulation rate and see if we can measure on a year by year basis 13,000 years ago which was the last time we had a big drought climate change so it turns out there's enough accumulation in this location you actually see layers of snow that are about this thick that are 13,000 and 12 13,000 and 1 13,000 and 2 13,000 right you can actually go in and measure on a year by year basis what was happening this is we're going to skip over all this stuff this is the context this is the period we were looking at this is about 13,000 years ago there's a bunch of these things I pointed that out before time is now actually going to cure in that direction there's a bunch of these abrupt changes and this was the first time back in the late 80s when we actually took a look at this and said are these things real are they real changes so this is a paper we published in 89 that showed that a 15 degree Celsius change occurred in about 50 years so when I started my college career lecturing to students I would tell them that 15 degree changes happened in a couple thousand years and their eyes would roll in the back of their head like sharks like give me something I care about when I told them it was 50 years I thought 50 years was really good now as it turns out there are other pieces of it that happened in 20 years I still couldn't get their attention now I'm going to tell you that there are parts of the system we've now dug into this even more where you can get 5 degree Celsius change very large change in less time that it takes to get through college does that get your attention and trust me the folks at Colorado are tough because unless it's next Friday which is their time scale of interest at all so here's an example this is again the younger guys we've now measured a bunch of stuff it turns out it's about a 10 degree C increase in Greenland temperature we're off by a little bit the snow doubled it was cruising along at a certain level and then in 1 to 3 years it doubled the accumulation and stayed there for that 12,000 years the accumulation of the amp in 1 to 3 years it changed there was a sea ice retreat in 1 to 2 years methane went up by 50% and 50% of methane is controlled by tropical wetlands so it was a global feature that was going on a lot of things were happening 10 degree C is Atlanta to Minneapolis 12 degree C is Mobile to Minneapolis so you're talking about a climate change that would take you from Mobile, Alabama to Minneapolis that gets your attention there's a whole bunch of them I'm not going to dwell on this you can see we have a number different parameters we can measure these things range anywhere from 12 and a half degrees to 10 degrees excuse me yeah is there an evidence of massive species extinction at the Corleys of those events? there are species extinction at the Corleys of those events there are all these species the extensions what I'm talking about is if you have a 10 degree Celsius over a period of just a couple of years you're going to lose a lot of species let me come back to that okay I'll come back to that so one of the questions we asked was are these things real? and since that first paper we found out that they are this is now two ice cores one here and one down here this separated by a pretty good distance in blue you see one of them in red you see the other and these are years 50 years, 50 years each of these points is actually a year you can actually see year by year change correlating one spot and another spot across here and what I think is even cooler is the we've now measured enough of these things and we can see that the this warming was in 1750 years was actually a step a plateau and a step and each of these steps is about one degree C for five years plateaued and then one degree C for five years one degree C for five years just to kind of help you remember this is about a hundred times larger than the warming that's occurred in the last century we've seen about a degree in 100 years this is about a degree per year this is so roughly half of the distance climatologically from Alabama to Minnesota happening in the time it takes you to get to college and then when your younger sister comes along and goes she gets the rest of it that's finally how I was getting an interest in attention to my students there were parts of this system that are even faster I'm not going to try to explain with the cheer and excursions but this is what we measure at every ice core that shows us that there is an ocean trigger to this event ocean conditions and atmospheric conditions change and they change very very rapidly one to two years and this has been doing this for thousands of years and then this does this for thousands of years and so what I like to tell my students is you know when your parents every parent tells every child when I was your age I used to have to walk through the snow uphill both ways and you know kids who are always roll their eyes and say no come on dad well there really was a time it's a problem we're talking about right now there really was a time when one generation had to deal with a fundamentally different climate than the next generation so there really was a time when a father or a wife or a mother said to their children when I was your age it was much much colder and we had to walk through snow it wasn't uphill both ways that's totally wrong but it really was so there really was a time you know I'm going to stop there for a good amount of time and we can talk I'm going to show you some cool stuff about how you pull a dome around and the issue but we can maybe talk about that I do want to leave some time for questions and apologize for that totally fine so I will wrap it up here now thank you so much for your kindness for all the stuff you've done for me over the last couple of days and for the students yes I'm going to get chucked up for you thank you very much