Major Sea Level Rise in Near Future | Jason Briner | TEDxBuffalo

so climate scientists report that August marked the 16th consecutive month of record-breaking heat climate scientists also tell us that 18 of the last 20 years were the warmest ever recorded on earth climate scientists are basically earth doctors they are probing the planet using a variety of instruments to diagnose its health in terms of the climate system some climate scientists are scattered across the poles and they're trying to gauge how all this extra warmth going into the atmosphere affects glaciers and ice sheets for example the Greenland ice sheet in the northern hemisphere and the Antarctic Ice Sheet over the South Pole in the southern hemisphere now the data and the images that they're bringing back are revealing unprecedented amounts of melt in the meltwater that all this warmth is creating is pouring straight into the oceans so I'm a professor of geology and I'm a climate scientist and I study glaciers and ice sheets so for tonight's talk I'm going to tell you about how I became to be a climate scientist and then I'm going to talk about two recent turn of events that have been real game changers and not only the field of climate science but also they have broad implications for everybody on planet Earth so I grew up in a suburb of Seattle playing in the Pacific Northwest Woods whenever I could as a child and my first encounter with a glacier was on a fifth grade field trip to Mount Rainier shown in this image one of the large stratovolcanoes in Washington State and on that field trip we walked to the Carbon glacier somewhat ironically named after the substance that might eventually kill it and on that field trip we learned that glaciers are basically where snow falls at high elevations and accumulates and forms thick piles of ice and that ice flows downhill due to the force of gravity now I eventually graduated from high school as a somewhat mediocre student not knowing exactly what I wanted to do in life but I went to college the local University of the University of Washington from which this view was from in this photograph in between my sophomore and junior years in college I had the opportunity to become the field assistant for a graduate student who's studying glaciers in Southeast Alaska so in 1994 the two of us went to Alaska to study the LeConte glacier shown here now the LeConte glacier is the southernmost Tidewater glacier in all of the northern hemisphere Tidewater glacier means it's a type of glacier that flows all the way down to the ocean and it breaks off icebergs at the end of it and those ocean currents take the ice out to the sea where those icebergs melt that experience for me getting to do science in Alaska on a real glacier was pivotal in my career it solidified my interest and inspiration to study geology and I eventually graduated from college and went to graduate school in the late 1990s I had the opportunity to work on glaciers and to reconstruct how glaciers change in the past like during the last ice age in Alaska where I got to go for several years that continued to seal the deal for me so eventually I went and got a PhD I did some post doctoral research and I finally landed a job at the University of Buffalo in the geology department and ever since that time throughout my career from the beginning up until now I've been studying glaciers and ice sheets pilant primarily in the Arctic so this is my natural laboratory this is a view of the Arctic and it shows all the glaciers and ice sheets that are scattered about and between that first trip in 1994 to a trip to small guard which is in the Arctic part of Norway just two weeks ago I've been to the Arctic more than 50 times to study how glaciers there are changing and how they're responding to climate change both in the past and today now the Arctic is a special place it's remote it's extreme it's magical and it's calm and it's I feel very lucky to have had the opportunity to visit these special places so frequently however doing fieldwork in these environments isn't always fun and games I've had more encounters with bears than I can count on both my hands and I've been stuck in tents for days while bad storms are passing by over head out of all these experiences getting to see the majesty and feel the adventure it's been working with students that has been the most rewarding for me so I get to take undergraduate and graduate students to the Arctic where we all do the science together and at the same time I'm training the next generation of climate scientists so this is a typical scene of what it's like to work in the Arctic almost everywhere I go across the Arctic it looks like this and this is basically showing a glacier that's not doing well this glacier used to be in the bottom of the valley which is evidenced by this pile of rocks that it transported to the valley bottom so we can tell that's where the glacier used to be the present glacier is way up here due to global warming this particular glacier and many others in the Arctic have retreated up to the tops of the mountains where it's still cold up there to support a glacier now what is it that we actually do to study glaciers and that's what I want to tell you next so much like a doctor might want to diagnose a patient if they're not feeling well they might want to know about the patient's history or the family history much in the same way we want to know the history of glaciers and how they've changed in the past what's their story in order to reconstruct these histories of how glaciers change through time we need to know a couple of things we need to know where the glaciers have been in the past and we do that by basically piecing together traces of evidence left on the landscape the glaciers left behind it tell us where they were like this pile of rocks up here below the white line called a moraine the other piece of information we need to know is basically when the ice was there and to do that we use dating methods geological dating tools that allow us to understand the age of when those pile of rocks are deposited so this is us on Greenland standing on one of those pile of rocks that the glaciers left behind sometime in the past and we're taking a rock sample we can bring back home to the lab and measure the chemistry in the rock and that tells us we're able to use that information to figure out the age of the deposit another way that we're able to reconstruct how glaciers changed through time in the past is illustrated in this image at the top of this four autograph is the Greenland ice sheet and you might see in this photograph that as there's knelt taking place on the ice sheet there's meltwater streams draining off the flanks of the ice sheet and those meltwater streams carry sediments and this particular image shows one of those streams flowing into a lake basin where those sediments go into the lake and they settle out in the bottom of the lake and accumulate as sediment layers in the bottom of the lake now these lakes are natural libraries that hold information about the ice sheet and how it's changed in the past so what we do another reason that requires all these trips to the Arctic is the fieldwork to collect the sediments from the bottom of those lakes so we go onto the lake surface and we pound a tube into the bottom of the lake and collect those sediment cores of all the layers that are stored in the bottom of the basin we bring those sediment cores back to the University where we study them sometimes we're in the field we need a sneak peak so we open them up and we can see the layers the changes that you can see in that sediment pile in the bottom of the lake and that's telling us how the Greenland ice sheet changed in the past now what my research has discovered is that of all the types of glaciers that are in the world it's the ones that flow into the ocean the Tidewater glacier is much like the LeConte glacier that first one I studied in 1994 it's those glaciers that are the most sensitive to climate change I'm showing you an image from space here of a very special glacier it's one of the largest glaciers on planet Earth and it's the fastest flowing glacier on the planet this glacier flows from right to left and the terminus or the end of the glacier is beneath that red dashed line and it flows so fast and it breaks off so many icebergs that the ocean can't take them away fast enough so to the left of that red line the ocean is chock full of icebergs it's like a giant cocktail up there and so it's hard to tell where the glacier ends and the ocean begins just for scale this iceberg I'm highlighting in this black circle is so large that you can not only fit one football field on this iceberg or to you could fit 20 football fields on top of this iceberg so how fast might you ask if I were to take you and put you on this glacier you would be moved six feet on the surface of the glacier in one hour and to put that in perspective if I were to put you on a normal glacier a typical glacier you would have to stand there a week in order to be moved six feet down Valley so this glacier is really truckin I'm going to back up the clock here 15 years and show you what it looked like in 2001 the entire image is covered by jakub Savini spray and by 2010 it had retreated substantially I've been working on this glacier for almost ten years and so I've actually witnessed this glacier experienced this tremendous retreat and just the relatively brief amount of time that I've been working in this part of western Greenland and by 2015 we've retreated back to this much now the retreat of jakob Sava nice spray is parallel but maybe to a less lesser magnitude by a lot of glaciers in the Arctic and all that retreating ice and melting ice is leading to sea level rise this is an interesting plot it shows sea level rise and it's interesting because it starts in 1780 goes up to today and then goes another 100 years into the future so before today these are real data that we have to constrain what sea level is done and what you can see is that sea level is already risen afoot in the last century and that furthermore in the next century sea level is expected to rise anywhere between 2 feet and 3 feet so by 2100 AD we're expecting sea level to rise by 2 or 3 feet now to give you a sense of what that might do to the world let's look at New York City so here's New York in its coastline at the current sea level already one foot up but I'm just putting it at zero feet here and I want you to see what 3 feet does to the coastline of New York now as I go to the next slide I want you to maybe just focus your eyes on one point like maybe Newark for example let's see what happens to Newark when we go 3 feet up we see that the sea is encroaching and some of the low-lying areas are starting to get covered by the ocean and it may not seem like that dramatic of a change for a city like New York of course there's a lot of island nations and other low-lying countries that have a much more stark impact from the sea level rise but I do want to remind you that that level of sea level rise one estimate from a reinsurance company suggests that global sea level rise of just three feet will cost 28 trillion US dollars to world economies so that's nothing to sneeze at so I want to talk now about the first recent turn of event that's been a real game-changer in climate science and it turns out that while my colleagues and myself have been learning these things about marine glaciers and Tidewater glaciers those glaciers have flown to the ocean on Greenland colleagues of mine who have been studying the Antarctic Ice Sheet have reached the exact same conclusion it's the glaciers that flow into the ocean of the most sensitive to climate change and this turning of event this discovery that I'm going to tell you about it has to do with this model that I'm going to show it's an animation and in my 20 years as being a climate scientists this is the most terrifying thing that I've seen about climate change and I want you to focus your eyes on the western part of the Antarctic Ice Sheet it's called the Western Antarctic Ice Sheet and this is part of the Antarctic Ice Sheet that terminates in the ocean this is where most of the Tidewater glaciers are and I'm going to play this model and it's going to start today roughly and move into the future so the clock is ticking we're moving forward in time pretty soon we're going to reach 2100 AD and it's after right about now 2100 ad that the West Antarctic Ice Sheet begins to collapse in between 2100 AD and 2200 ad basically the entire portion of West Antarctica is gone it's melted into the ocean if we translate that map view of the ice loss the retreat of the West Antarctic Ice Sheet into sea level rise we get a graph like this this is basically projecting into the future and then you can see sea level rise in the vertical axis by 2100 AD it looks like this is going to lead to 2 or 3 feet of sea level rise so I want everybody in the audience to take your hands and hold them about 3 feet apart that's about what a three-foot sea-level rise can do now I want to show you 2200 ad by 2200 ad we're talking 20 feet now everybody just entertain me hold your hands 20 feet apart right that's an enormous amount of sea level rise and that's what we're talking about the future if we return to New York I'm going to reset it at zero I'm going to show you three feet and I'm going to show you 20 feet this is a dramatic dramatic change to New York and the rest of the world it turns out that one in ten people lives within 20 feet of the ocean on planet Earth today so this would absolutely be a catastrophe but I want to talk about the next recent turn of event that's also been a game changer and it has to do with how we're emitting co2 in the atmosphere this is a plot that shows the future projections of the co2 that we're going to be putting in the atmosphere now the co2 is what leads to the global warming which is what leads to glaciers retreating which is what leads to sea level rise the upper most red curve is what we call business as usual scenario and if we're not careful about how much co2 were emitting this is our trajectory and we'll be over a thousand ppm by 2100 AD however last December the world came together and derived a document a path floor that's referred to as the Paris agreement and it turns out just last month enough of the nations came together to buy into the Paris agreement to reach the critical threshold target level that now this agreement is going to go to enforce and the agreement goes in force it would put co2 in the atmosphere more like this purple curve much more reasonable and if we're returning to the sea level plot what I showed you actually before was the collapse of the West Antarctic Ice Sheet according to this business as usual co2 scenario let's look to see what the Paris agreement scenario does much less sea level rise in fact closer to 10 feet than to 20 feet by twenty one twenty two hundred AD and I think actually the world can't come together to make this happen there are several examples of how the world has come together to work towards improving the environment in the 1960s we banned above-ground nuclear bomb testing in the 1980s we banned the use of CFCs those things that kill ozone and now the ozone hole has stopped growing and it's starting to fill back in but it's not to say that this is without some challenges achieving this goal is without some challenges I'm showing you now two quotes from the top political leaders in our country that represent the wide spread views that our nation has about global warming there is a view out there that a lot of US citizens have and political leaders that climate change is a hoax and not to be taken seriously and there is an opposing view that treats it very seriously climate change is real it's hurting our planet and our people and you might ask why is it like this why are there such widespread views why is the conversation focused on is global warming real or not and not what are we going to do about it how are we going to help fix the problem and so for example to ask that question think about the patient who goes to the doctor and gets a diagnosis then the doctor says okay you got this some disease and that's a hard thing to swallow so you seek a second opinion let's say you seek 100 second opinions in 97 of those 100 second opinions agreed with the first doctor you wouldn't hesitate to act on that advice now it turns out there's been a smear campaign in our country against climate science and against climate scientists that's led the conversation astray it's muddied the water and it's led us to confront this issue about whether global warming is real or not and actually not move on however I think there's two things I want to say here one is that the world is coming together there is momentum and I think we're on the right track towards solving this problem the second is that we're really only one election away from having one of these two viewpoints be in the leading position of our country so it's still very critical I would like to end with a photograph of my two-year-old son standing on the coastline of the Pacific Ocean on looking out at a sea that's already risen one foot in the last century this could be your son or your grandson or your great-grandson and they're going to be looking into the future they're going to be experiencing this catastrophic sea level rise potentially if we're not careful about the decisions we make and I just want to I was reading the other day the last service member in World War one that war that occurred a hundred years ago didn't die until 2012 just a couple of years ago 100 years is not that far in our future and we right now are making decisions for our future generations thank you [Applause]

Channel: TEDx Talks

Views: 167,108

Rating: 4.2226806 out of 5

Keywords: TEDxTalks, English, United States, Science (hard), Climate Change, Global issues, Research

Id: f7sEhuSbQo8

Length: 18min 53sec (1133 seconds)

Published: Fri Dec 09 2016