day. that will be live from capitol hill, starting at 5:00 p.m. eastern here on c-span3. tonight, president trump will address the nation on what the administration is calling a humanitarian and national security crisis on the southern border. this is the president's first address to the nation from the oval office. house speaker nancy pelosi and senate democratic leader chuck schumer will respond at the conclusion of the president's remarks. live coverage starts at 9:00 p.m. eastern on c-span. welcomel go into our spotlight welcome back, and we're going to go into our spotlight on magazine segment, where we're going to be talking with "wired" magazine contributor rod gerdner about his recent piece about climate change. john, good morning. >> good morning. thanks for having me. >> so what made you decide to write this piece? and why did you focus on the glacier right now? >> i write a lot about science

for magazines and newspapers. and really, the big story in climate change, or one of the big stories -- there's a lot. we talk about temperatures going up, we talk about coral reefs endangered, we talk about food supplies. but one of the biggest is sea level rise. and the biggest influence on sea level rise is the potential for these vast ice sheets, both in greenland and antarctica to fall into the sea. and when the ice on land slips into the sea, it can do it by melting and running off or these huge icebergs can go into the ocean and sea levels go up. what that means, of course, is coastal cities are i am imperilled by that. there are a lot of projections on what's going to happen by the end of the century on how much sea levels will rise. but one of the danger points is this group of glaciers in

antarctica. this is as far as you can get from the rest of the world. these are really remote places. but these portions of the ice sheet that hold a lot of water, and they're on the land, and the worry amongst the science community -- the scientists i talked to, the glacierologists, is that these glaciers are potentially unstable, and as the world continues to warm, they will really kind of cut loose from their mooring place on the land and fall into the ocean with these massive icebergs and what could be a really, really significant sea level rise. >> so you called the weights glacier. am i pronouncing that correctly? the thwates? >> that's correct. >> so you call it the most terrifying glacier. explain why this particular glacier can cause so much trouble. >> if you've ever been to, say, alaska or seen pictures of, you know, glaciers say in greenland or canada or switzerland, even.

they look like rivers of ice. these narrow sort of rippled rivers that flow down through mountain passes. and they can be quite beautiful. and they advance and recede almost like a river might. but thwates is kind of different. it's much bigger than a river of ice. it's about 100 miles across. it's many thousands of feet deep. it goes for hundreds of miles, inland to west antarctica. so really the first thing to know is that it's enormous. it's about the size of florida or great britain. the second thing about thwates is that it seems to be unstable. that warmer waters around west antarctica in a region known as the onmonson sea, it's becoming unstable. the third thing is when thwates starts to enter a period of what glacierologists call collapse,

it could reach sea levels of several feet. it's interconnected to a bunch of other glaciers in west antarctica, and it's almost like losing the back wall of a house. if thwates goes, everything might collapse. and in that scenario, which is very dire, which is not imminent, but is possible, we're talking somewhere like 10 or 11 feet of sea level rise. >> well, in fact, in your article, you talk a little bit about some of the worst-case scenarios if water levels go up 15 feet. for example, right here you say, in that scenario, the jefferson memorial and fenway park would be under water. and the google plex would become an arch pail go. outside the u.s., the damage would be incalculable. all would flood or drown. what are we doing to be able to tell if this is going to happen? >> well, at the moment -- and the reason i wrote such a long piece is we're about to embark on a collaborative scientific

effort with great britain called the international thwates collaboration. this involves many dozens of scientists who are doing all sorts of different missions to go to this glacier. and it's really hard to get to, as i said. it's about -- almost 1,000 miles from mcmurdo station, the main staging ground in antarctica. this is an effort that is going to stretch really over the next four or five or six years to investigate how fast this glacier might become unstable. because we really don't know. we have models. scientists use computer models to try and look at what temperatures might be in the future, for instance, by looking at where carbon dioxide missions are going. it gets trickier when trying to predict movements of the glacier. the physics are really complicated. we don't know necessarily what's underneath the glacier and how

fast it might slide or move back or retreat. these are all questions that teams of scientists are going to investigate over the next few years. and the idea is they'll collect data, they'll collect information about this remote glacier. eventually, it will be able to be plugged back into these models, and it might give us a better picture, not so much about whether thwates will collapse. there is a lot of agreement that some collapse of this glacier may be inevitable. but the real question is how fast. if it's over the course of 1,000 or 2,000 years, there's a lot we can do as a society to change our ways to alter the trajectory of the warming climate that might have real, real impacts about this glacier. but if it's a more dire scenario, if it's one of those worst-case scenarios like we were just -- you were just talking about from my story, then things become much more complicated about, you know, what can we do to try and sort of stem the collapse of this crucial chunk of ice, really. >> let's let our viewers join in

this conversation. once again, we're going to open up the lines by region. if you are in the eastern or central time zone, you can call in at 202-748-8000. if you're in the mountain or pacific time zones, you can call 202-748-8001. and keep in mind, we're always available on social media, on twitter, at c-span wj, and on facebook on facebook.com/c-span. and let's go to cliff who is calling from essex, maryland. cliff, good morning. >> caller: good morning. thank you all for c-span. let's people get their opinions out, as well as the facts. i would like your guest to, if he can, to let the viewers know what government agencies are responsible for geo engineering. >> yeah. maybe i can just define geo engineering for people who are watching who might not know much about that.

it's about using a human intervention, some kind of engineering technique to alter climate, or in this case i think cliff might be talking about alter the collapse of a glacier. in my story, there are some ideas for maybe building something underneath this glacier -- underneath thwates glacier to protect it from warming waters in the sea so the glacier wouldn't affect the protected and might not break down as quickly. this is a tremendously complicated idea. we have never -- nobody has ever built something like this. but this would be classified as a geo engineering project. geo for earth, trying to engineer the earth's system. there aren't really any agencies responsible for this at the moment. these are sort of still in the realm of ideas, or basic science. so it's not like -- there are people at nasa, for instance, and nsf who can discuss this.

these are controversial ideas in many cases. they may have unintended consequences. we've -- another geo engineering idea, for instance, is to put sulfate or particulates in the upper atmosphere so that sunlight is reflected back out into space, so it would in effect sort of delay the onset of rapid warming that's now happening on earth. the -- it's -- that kind of geo engineering is meant to mimic volcanic explosion. but, again, that's quite controversial. only now are experiments beginning to happen. there's a harvard professor who is looking into doing something on that. but, again, it's not in the realm of government. it's not in the realm of anything beyond basic research at this point in time. >> let's go to bill, calling from norfolk, connecticut. bill, good morning. >> caller: good morning. how are you? and happy new year. >> same to you. go ahead. >> caller: what i was going to say is, is it possible that we

can't reverse this trend? that even if we didn't emit any carbons or anything, that it may be too late, you know, in cities like new york, sacramento, new orleans? th they'll have to abandon them. >> that's a great question. it's something i discussed in the story, too. what we're looking at for the future in a lot of cases are these computer models. how will glaciers or these ice sheets in greenland and antarctica react to a warming climate or warming ocean. and what modelers often find out is that if we sort of change the trajectory of our co2 emissions, which would be keeping the climate to, say, 1.5 degrees warming, this century, and this for people who are more familiar with this idea, this is part of the treaty that was -- or the agreement that was hammered out in paris in 2015.

if we could do that, it might, in fact, make a very, very significant difference in how fast these glaciers break down. so there's a lot we could do. the question is, how can we do this politically and socially. and at the moment, the news is not very encouraging, i think. i mean, the united states has sort of showed its intentions to not participate in the paris agreement. we also have this past year reached a new milestone in terms of co2 emissions. so we're not going in the right direction yet at all. and probably the best way to sum this up is if we really wanted to get serious about meeting these targets for limited climate change, we would have to undergo a rapid, almost immediate switch to renewable energies, technologies, and that would include really anything that produces carbon in transportation and power generation, and we would have

really to alter our entire systems of society. >> let's go to milli, calling from asheville, north carolina. milli, good morning. >> caller: good morning. you know, i don't know if your guests are aware, but there was a mini ice age in europe during medieval times. and i would like to know, what brought the end to that mini ice age? obviously, they did not have the technology that we did now. so was it from their peat fires? what was it? >> is that something you can address? >> yeah. it's a little bit -- i don't want to go too deep into it, but what i think it's useful to say is that earth's history as reconstructed by scientists who have researched this through glacierology, geology, all sorts of other clues they've gotten to the history of the earth, have -- you know, it's obvious that earth has gone through

numerous warmings and coolings over the last several million years. the little ice age is one tiny example. there were much more significant increases and drops in temperature that have occurred, for instance, 11,000 years ago. there was a great warming trend in the arctic regions. but i think what's crucial to say now is we're undergoing a period of extraordinary warming, due to industrial emissions. and this is sort of a change unlike any that's gone before. so we have now entered a new era, i think the an throw posey at a rate which really appears not to have any kind of precedent in recent history. >> let's go to tom, calling from illinois. tom, good morning. >> caller: good morning. first thing i want to say is, al

gore wrote a book two years ago, and in that book, he said that in ten years, washington, d.c., would be devoid of any kind of snow, and that the children would not know what it is. and on that anniversary they were all sleigh riding down the hills. the point i'm trying to make is, i'm a farmer in illinois and last year we had record crops, we've had record crops for the few years that we've had it, for i think six years now. and prices have gone down. and nasa takes satellite imagery of our fields and in those fields, they have found that the corn fields produce more oxygen than the rainforest in south america during the growing season. now, my point is, i listen to a lot of different scientists, and

one of the scientists said that if you wanted to correct the co2 level in the world, that you have to stop all emissions now. you would have to get rid of your cows and bovine because they put emissions into the air. and you would have to stop breathing, because that's what you emit when you breathe. and it wouldn't change the amount of co2 in the atmosphere by 1% in 30 years. so -- and part of it is, too, i just got through talking with university experts, we don't do any studies on what the carbon is doing to the crop. and if you come out here in the spring and you look at the trees, and you look at the corn, and you look at the beans, they're extremely green. and part of that, i think, is because we have a lot of co2. because the other thing is, co2 is a food.

plants got to have that to live. so i don't buy this. this is all about taxing us again, taking our money, and doing something that's far-fetched and won't do any good anyway. >> how sound is the science here? >> well, there's a lot to chew on in there. i just might point out, we should make a distinction between weather and climate. one snowy winter, or, you know, one cool summer does not necessarily indicate a particular trend of any significance. i think also it's important to remember that we are just one tiny part of a very large earth. as important as washington is, it's really just a dot on a map of an enormous, enormous planet, really. so whatever weather is affecting us nearby when we look out the window can be very different from what larger trends are showing us, and we see that in data that's collected from nasa and other agencies around the world. in terms of co2 science, actually there's a fair amount of science that agricultural

scientists are doing around the world to understand what increased co2 levels will do to plants. i think while it's out of my sort of sphere of -- it's outside of what i write about as a journalist, i'm aware that there are, you know, these studies, and it's an ongoing concern, especially with the idea that co2 levels are going to continue rising for the near future. as for whether this is a good thing in the long term, i think we can almost absolutely positively say that rising co2 levels will not be good for anyone including farmers. they will change growing seasons. they will alter the tried and true methods and systems that farmers all around the world have depended on. they will shift areas where certain crops can be grown and can't be grown. they'll alter sex and other

pollinators. i think even if our friend on the phone had a good season, which is certainly a good thing, i think the long term trends are, the impact is very dire. >> jonathan from minneapolis, minnesota, jonathan, good morning. >> caller: good morning. first off, it is a lovely, warm, 45 degrees in january. usually we have minus 15 degrees below zero and 15 inches of snow on the ground. if you don't think global warming exists, take a look outside, people are walking around in shorts and flip-flops. my question to you, sir, with the glaciers and rising waters, which direction we can do to -- not that i'm missing the snow, but how do you think we can reverse it to make it a little bit better for the next generation and the world that we live in right now? because at this rate, we won't

have a -- unfortunately that's the way the world looks like it's going, at least i can go outside and wear shorts in minneapolis, so god bless. >> that's a great question. i think that, you know, there are -- earlier i painted sort of a kind of darker scenario of how co2 emissions continue to rise, and there doesn't seem to be a kind of political movement, at least at the moment, in the country. i should rephrase that a little bit. i think what we're saying with, say, the green new deal in congress that's being discussed, with what we're seeing around the world in various countries with discussions of carbon taxes, with switching over to more renewable energy systems, with the sort of advent of electric cars, there are these sort of vast transportation systems, energy systems, moving away from coal-fired plants.

there is a movement, there is a lot of encouraging sort of progress. i think it's just that the overall trend is very difficult in the sense that we have an expanding population that needs energy, that needs food, and the requirements for that kind of have left us to depend on an older infrastructure that unfortunately emits tons and tons and billions of tons of carbon every year. so what we can do is try and accelerate that trend. i mean, there's a lot of -- accelerate that trend towards greener energy, towards renewable energies. there's a lot of discussion in the climate community whether this should be an individual action or a concerted sort of group action, which is more important. i guess, you know, it's a matter of personal opinion, but i tend to think that et ceterait's all important, it all matters. making a personal decision to drive a more fuel-efficient vehicle matters. making a decision to vote for a

representative, political representative of whatever party you may support, but somebody who does support renewable energy technologies and is interested in switching over towards cleaner technologies, matters quite a bit. so i think, you know, there are a variety of actions, and i won't go through them all, but certainly you can fly less on airplanes, you can certainly eat less meat. those are personal decisions. i think the big ones are really changing these systems that emit billions and billions of tons of carbon. that would be transportation systems, that would be energy systems, especially coal power plants. those are really the kind of big, big things to tackle in the next decades. >> one of the ways that they study the health of this glacier is by setting off small explosions on the inside. explain how that works and why this isn't detrimental to the glacier breaking apart. >> right.

so thwaites glacier, there are all sorts of scientists who are descending on it to study it. some will be looking at it from the water's edge, some from above through radar and satellite imagery. the scientists that i wrote about use literally bombs. they drill holes in the ice. they put a small explosive in it. they cover up that hole with snow and they detonate it. and they look at the way the waves travel from the site of the explosion to the bedrock beneath the ice sheet and then back up to the surface. and by doing that, they can kind of understand a bit more about the bed, the glacier bed that's underneath all this ice. and the idea is, if they can understand that better, it will give them a clue to how fast or slow the glacier might slide back and retreat and collapse over the coming decades. now, these are small bombs. they're about the size of your

index finger. sometimes they'll put two or three or four together. but they're not big enough to in any way sort of break the glacier apart or even fracture it in any significant manner. the forces of nature are much, much more powerful than these small bombs. >> let's go to matt, calling from cleveland, ohio. matt, good morning. >> caller: hi, how are you. i'm wondering, sir, mr. gertner, is that how your name is pronounced? >> that's right. >> caller: what is your technical background? do you have degrees in atmospheric chemistry or things like that? >> i'm a science journalist and a technology journalist. i've written a long book on the history of bell laboratories, which was the great laboratory of the 20th century that invented the transistor, laser, information theory, a lot of other things. i just finished a book about the

greenland ice sheet, which is out in june. i went to greenland six times for that. i've spent the last few years writing about glaciers all over the world. so no, i'm not an atmospheric scientist. i talk to scientists all the time, every day, almost, and that's pretty much my work. >> let's go to bob who is calling from philadelphia, pennsylvania. bob, good morning. >> caller: good morning, c-span, thank you for taking my call. i think that you just kind of proved the last caller's point, that sir, you are not qualified. you are essentially a parrot who repeats what other people tell you. and you only go to the sources that you want to go to. now, i'm sorry if that's insulting to you, but it's unfortunately the truth. the other point that i need to make is that at a time when, you know, the president wants to get, you know, money to build a wall, okay, to effectively -- >>