icefield. >> today on "earth focus," from monitororing glacier melt and arcticic sea ice to what scientists s climate c change may mean for ouour future, coming up on "earth focus." >> on the edge of the gulf of alaska, straddling the icy border with canada and the coast range mountains, lies the juno icefield. this is the fifth largest expanse of ice covering the planet and is the source area for hundreds of glaciers.

the juno icefield research program, or jirp, has been studying these mighty rivers of ice since 1946 to better understand how our planet's natural environments are changing and what this means to our common future. >> andnd actually there's a lite bit of complexityty as to why we use glacier ice.e. >> i came here as a science student 23 years ago and returned to work here this summer as a part-time staff member. like other jirpers, as we call ourselves, this project launched my interest in the natural world and continues to inspire my scienence reporting. each year a group of science researchers crosses this vast area like i did, getting a chance to learn how to survive and conduct research in this, one of the most wild classrooms in north america. supported and

staffed by the foundation for glacier and environmental research, the juno icefield researchch program has some of e longest-running glalacial climae records in the world and is a treasure trove of valuable data about how our world's climate is changing. i'm here at camp 17 on the juno icefield, and i'm going in to have a quick word with dr. anthony arendt. he's from the university of alaska in fairbanks, , and he's one of the guys who designed the latest satellite imagery systems for nasa to understand the mass balance of this icefield. >> glacieiers respond immediatey to any changeses in climate.e. e variations and their mass are determimid directly by how much snows falls on them in the wintertimime and how much ice ad snow melts away due to warmer temperatures in the summertime. so by monitoring glacier variations, we can understand a

lot about climate systems, andd so thehey're onene of the firsrt of early hahallmarks of climate change on the planet. >> dr. arendt helps create high-resolution computer models of glaciers like this one using data from satellites, airplanes, and deep snow pits like these to develop a clear picture of our future global climate. 95% of alaskan glaciers are melting at an unnatural and unprecedented pace. >>glglacie a are really y large contributors to changing sea levels. you want to be able toto quantify how much water is coming out of these systems every year and then use that information to develop models and predict in the future e to help policymakers plan for potential facts of sea level change in the next 50 or 100 years. >> scientists lilike dr. arendtt come here to conduct research and to share their experience with the young-and-upcoming researcrchers takaking part in e program. to collelect the ground

data that sophisticated high-tech sciencece depenends o, students have to cross vast distances through the isolated heart of the icefield. in order to traverse the icefield safely, we train them extensively for the dangers of this rugged field experience. here at camp 17, they learn adventure skiing, safe glacier travel on a rope, and how to rescue a colleague from a crevice. the training equips and inspires these students for a carereer in exexe environmental research, collecting data that t the globl sscientific cocommunity depends upon to furtrther the understanding of our changing worlds. >> it's just a useful tool in itself. >> first off we practice tying knots. that was like the basis of all this, and then from those knots, then we learned different ways to use ththe knots on a ro, which then you learn h how to si with a rope team and w what to o inin case anything bad happens n a rope team, like a fall into a crevice and how to save a team

member that has fallen. >> yay! >> after science and safety training at camp 17, the participants start their traverse across the icefield, doing field work in geology, glaciology, climate change, and other disciplines. >> well, when these people come out of the icefield and experience t the glacicial environment, by making measurements, they can see how that ecosystem is changing this year and in years before. >> to be on the juno icefield is a fantastic experience for me, and part of a major program that monitors mass balance of an important glacier, and in addition, it gives me the opportunity to try and contribute to the scientific development of young scientists. >> mass balance indicates the health of a glacier. a posisitie mass balance means that the glacier is growing. a negative mass balance means that it is

shrinking. the older a mass balance record is the more valuable it becomes. long-running studies provide a historical average against which this year's data can be compared, showing how the climamate has changed and what y happen in the future. >> the mass balance data that's been collected by the jirp program is an extremely important record because it goes back as far as 1946, and there are probably only about 30 glaciers inin the wororld that e been monitoror for mass s balaee for 10 or r more y years. >> a glacier exists here because snow that falls in the winter does not melt completely in the summer. the relative amounts of snowfall and melt represent this mass balance. like a positive bank account, a positive mass balance indicates that the glacier is growing. on the flip side, if the glacier has less snowfall and more melt, the glacier becomes smaller. so how have generations of scientists

come to grips with the estimation of the health of this 3,900-square-kilometer ice sheet? they dig. a lot. by digging many pits like these, scientists like dr. jason amundson calculate how much melted ice is flowing into the ocean. >> when the glaciers are actually in retreat, the one thing they do is theyey contribe to sea level rise, but they also affect atmospheric circulation patterns, which propagates downstream. it affects other things. the changes in the amount of freshwater runoff into the ocean, which will affect the ocean properties, which could affect t the marine e life. >> the glglobal sea l level is g to rise, and it will rise by varying amounts depending on where you are in the world, and the contntribuon f froglacieiers is lilyly to be sigignificant..

>> didigging owow pithas s been useful for almost 60 years on the juno icefield, but when these snow pits are paired with new ground-breaking technologies, the science becomes even more succccessful. salvatore candela is using a powerful ground-penenetrating radar, or gpr as it's known, too get information from the vavast areas between snonow pits using the pits themselves a as a reference fofor his readings. >> the digigging of pits and usg ground-penetrating raradar realy tities well totogether. since 'm imaging what's in the ground and they're actually digging in the area i'm imaging, they compliment each other in that if i have a question about what i'm seeing on the radar, i can go jump in a 5-meter-deep hole and actually see what is there. and by pairingng their visual observations with what's on the radar, it allows usus to come ta mumuch stronger conclusion a abt

where the e annual layer is or ere a spececific densi change might be that they're looking for in the mass balance process. >> by dragging his gpr sled, named the bumblebee, and using the pits to calibrate it, candela is helping create a much better understanding of this dynamic glacial system. the researchers also map the movement of the ice with gps and 3-d imagery. >> ...successful? >> i i think we're very successful. jerking it around. > ok, so i grab it, and i moe it around to that. wow. >> they even get deep under the ice in vast complexes of subglacial caverns to calculate how the glaciers are melting from the bottom up. the huge llewellyn glacier in canada is meltining fast, exposising moref

its secrets s for researchers brookeke stamper and mirira dute to discover, using photogrammetry and ice lens measurements. as the 2013 field season on the icefield comes to a close, we make our way northeast and walk off the llewellyn glacier through a dangerous crevice field. >> we're windingng our way throh thehe creviceces of the llewelln glacier. everyone's making their way very carefully here because the glacier gets a a little bron up, but itit's a beautiful day, and it looks like we might make it all the way to lake atlin. >> wewe struggle down through ts dusty and blowing newly uncovered ground where the vast llewellyn has melted and finally we make our way down this long valley to lake atlin. here we're picked up by a boat

andd start deciphering the data anand working it into the sscientific literature, , where researchers around the world can use it to fine tune their climate change predictions. from the glaciological and arctic sciences institute on lake atlin, british columbia, this is jeffrey barbee reporting for link tv. >> glaciers are not the only things melting. so is arctic sea ice. just how fast is the sea ice melting? research scientist julienne stroeve is working with the national science foundation to find out. >> i know the importance of snow and ice in helping regulate the planet's temperature, it's one of the reasons i wenent into studying snow and ice because it's very important to our climate system. and i don't

think it really was until about 2002, 2003 that we started to really start paying attention to what's happening in the arctic, because before that we would have, you know, we'd have low sea ice in the 1990s and then it would be followed by a high sea ice year, but what started happening in 2000 is you'd have a low sea ice year and another low sea ice year, and it just kept happening and happening year after year. and that was the thing we hadn't seen before, at least during the last sort of 50 years of data colollection. and then when 2007 happened, where you had 26% drop from the previous september in 2006, and everybody was like, what is going on? 'cause nobody expected that large of a drop. it took everybody by surprise in the science community. ththe rate of decline right t nw ovever the last 3 decades iss at 114% per d decade, and this is actually faster than most of our kind of models are actually capturing today. these projections of ice-free dates of, likike, 2050 to sometime beyond 2100, it looks like it could happen a b bit sooner, so like 2030 might be a more realistic date as to when we might see no sea ice in the

summer in the arctic. you know, basically everything on the planet's connected, and the arctic is sort of the big refrigerator for our planet. it helps keep our planet a lolot cooler because, as you know, snow and ice reflect most of the sun's energy that comes in during the summer period, so if you remove the snow and you remove the ice, then the land can absorb that heat from the sun or the ocean can absorb the heat from the sun and warm up further and amplify the warming in the arctic for example. all of our weather systems or large-scale weather patterns are driven by that temperature difference between the equator, which receives most of the sun's energy, and the polar regions, which receive very little of the sun's energy. but if you change that difference in the temperature between the two regions, you change the speed of the large-scale weather systems that move around the planet. as you change the temperature gradient, these weather systems start to move e more slowly through our atmosphere, and you can get more extreme conditions such as droughts and floods that just last longer in a particular region because these weather systems are moving that much

slower. and so there is a connection between what happens in the arctic and weather in the lower latitudes. and we knew that if the planet started to warm and you start melting snow and you ststart melting ice, thn youu're gonna have this sortrt f feedback effecect that's gonnana amplplify the warming because you're gonnana warm up. you'rere gonna melt more snow. you're going to melt more ice. it's going to further warm everything up and melt more and more snow and ice, so you have this really vicious positive feedback. so we e knew that the arctic was very sensitivive to increases in temperature, and it's responding like you would expect it toto as the temperatures have warmed, so it is sort of an early-warning system. we did expect changes to happen first there before everywhere else in the planet. if you looked at the factors that we tended to use to explain past low sea ice years, and those factors really weren't working anymore, so it wasn't necessarily a certain weather pattern or, you know, a certain temperature pattern that was causing it. there's some sort of background force that was happening on the ice cover that we, you know, were trying to figure out what that was. when i started lookiing at the climate model l and comparing tm to the observation, then ii

started realizing, well, you know, all ofof these models woud be an own facace of natural climate v variabilitiesso t they could be showing i increaseses r decreases over a period of observation, but theyey all shoa decrease, and so that's what starts to help implicate greenhouse gases that's forcing the changes that we're seeing today in the ice cover. we can say that about 50%-60% of the loss of sea ice that we're seeing today is a result of greenhouse gases. the other 40%-50% is actually y natural climate variability, so we know both are acting on the system right now. and right now the resesults are about 5 50/50, i think, on what's happening, what we're s seeing todaday. the planet's going to warm by a certain amount a degrees. the sea ice is going to disappear in the summertime. the ice is continue to respond, sea level is going to continue to rise, but when we look at things like, well, where are the precipitation patterns going to change? who's going to get morore rain? who's going to get less rain? ? what's going to happen to the american sououthwest? are e they going to lose their snowfall? in that sense, there's not a

whole lot of robustness between the model simulations yet, so they give different answers in different regions, and so we don't have a good handle, i think, on how rainfall, for exaxample, is goingng to changea warming clclimate. and that't's really i think one of the key things that we need to better understand is where is the water going to be? because a lot of regions depend very strongly, for example, on the glacier, to feed the city and provide all the water for a city like santiago, chile, for example, and so better understanding on how precipitation is going to change and snowfall is going to change is one of the key things that we need to understand. wwe do see t that if youou run point-lititigation scecenarios anand you rededuce ththe amount o of greenhououse , that t you can acactually bririe icice back. yoyou can stababilie amamount of i ice loss. i if wee toto reduce ouour greenhououse , it's not going to be this runaway effect. we can stop some of these changes that are happening in the arctic, but that does meanan we're goioing o have to cocommit to reducing the amount of fossil fuels we're putttting in t the atmososphered that's the real challenge.

>> most experts say fossil f fus are the leading cause of climate change. the climate change deniers often associated with the fossil fuel lobby and industry-supported think tanks downplay the connection between fossilil fuels and the warming f our planet. climate scientist michael mann on how a changing climate may affect our future. >> sometimes you''ll hear from the e itics. thehey'll say, "we demand proof that humanans are causing thihis." and my response is that t proof is reserved for alcoholic beverages andd mathematitical theorems."tt doesn't characterize how scienee works. science works thrhrough weights of evidence, through likelihoods, through confidence levels, and so we're about as certain that humans are causing global warming as we are about any scientific proposition, but we never say we've provenen someththing in science because there's always the o outside chahance that w we could discovr

some new piece of infnformation that would change ouour perspective. it't's absolutely true that critics of sort of the forces of antiscience, those looking to confuse the public about the science will always draw upon that vulnerability, that as scieientists we're never comfortable inin stating things in absolutes because that's not the w way the world works, tha's not the way science works. unfortunately our detractors, thoose looking to sort o of pole the public didiscourse on mattes of science like glglobal warming are more ththan happy to state their opinions witith absolute certainty. so it's important to undersrstand that there is sortf an asymmetry in the battle over informing the public about scicice. we're at a a bit of a disadvanantage as scscientists because we have to be true to our principles. weweave to bee honest. and we have to recognize and describe things in terms of caveats, in terms of layers of uncertainty. there are no absolutes. that having been

said, it's perfectly appropriate for a climate scientist to say we are nearly certain that the globe is warming because of us, because of increased greenhouse gas concentrations from fossil fuel burning and other human activities, and if we continue on the course that we're on, we are likely to seeee very damagig impacts on us, on our environment. one of the valid, in my view, criticisms of the ipcpcc is that in many respects i it has been overly conservative in the way it has stated its conclusions, and there's no better example thaan the melting of ice, both sea ice, the layers of ice that form seasonally in the arctic, and around antarctica, and land ice, the major ice s sheets, the continental ice sheets like the greenland ice sheet and the antarctic ice sheet. in both respects, both in terms of the shrinking amount of sea ice, for example, in the arctic at the

end of a summer. the kind of trajectory th we're on leads to the conclusion that within a matter of a couple of decadedes, wewe may see ice free connditis in the arctic at the end of the susummer. this is sosomething tt the climate models predict shouldn't happen for another 60 years, 'til the end of the 21st century, and indeed nature seems to be on a course that's faster, that's more dramatic than what the climate models predict. we arere already observing and measuring a decrease in the amount of ice in the greenland ice sheet and the west antarctic ice sheet. now, the climate models have predicted that we shouldn't see that for many decades to come, and the key distinction here is if it's a land ice sheet, a land-based ice sheet, then when it melts, it actually contributes to global sea level rise. that's not the case for

sea ice, but it is the case for the continental ice sheets, so the fact that we're already measuring losses of ice from these major continental ice sheets means that they're contributing to sea level rise faster, once again, than climate scientists projecected them to. there's a credible body of work now that suggests that if we contininue with business-as-s-ul fossil fuel emissions, than by the end of this century, we could see as much as two meters, 6 feet of global sea level rise. now, that would be catastrophic for many coastal regions. for the u.s. east coast and gulf coast, island nations around the world, some of which will literally be submerged by that amount of sea level rise. the ipcc makes a far more conservative statement. they state an upper bound of a abouta meter, about 3 feet, and it's once again an example of where the ipcc arguably has been overly conservative. some as

myself have argued that partly that's just due to the culture of science. scientists tend to be reticent.t. we don't like to mamake strong conclusions that e have to withdhdraw at some later time. and there''s also aa cocomponent, i believeve, due to the pressure, ththe outside pressure, , the critics, a very well-funded and well-organized effort to literally discredit the science of climate change sometimes by attempting to discreditit the scientists themselves. i myself have been a victim of that. and in the face of all that pressure and those attacks, i thihink to some extet the ipcc has a actually withdran a a bit, and they've been more guarded, more conservavative, ,e reticent in what they're willing to conclulude than they really should be givenen the evidence. anand arguably, you know, if it is indeed the ipcc's role to advise governments on the potential for dangerous anthropogenic interference with

the climate, which is what the ipcc was originally charged with as t their misission, arguably u should not downplay the higher-end scenarios if they're credible, eveven if they'rre low probabability outcomes.s. if thr probabibility isn't zero, thehen they should contributute to the assessment of risk much in the way that, you know, we buy fire insurance for our homes not because we think our homes are going to burn downwn. that''s a very rare occurrence. it's very unlikely to happppen to us, but eveven though its probabilititys very low, the magnitude of cost, the impact on our lives ifif our house w was to burn dowown is iimmeasurable. mitigating climae chchange, doining something abot our r carb e emissions is s a planetary insurancnce policy, ,d in guiding g the terms of that iinsurance p policy, we e need e focusing on some of f those pototential morore extreme catastrophicic outcomes.s. if te

ipcc systematically downplays those outcomes, thenen it does't seserve thatat larger process of societal risk assessment as it should. qualitatively speaking, if you look at impacts on human health, water availability, human water resources, food resources, land, the global economy, pretty much every sectoror of our lives, of human civilization, what you see is a business-as-usual fossil fuel burning scenario, by the end of the century gives us highly y negative impactsts acrs the boards in all those categories. i forgot to mention biodiversity, a potentially large-scale extinction of species. some of these we can ququantify ecoconomically or w n try to. some of them we can't even qualify how important they are. what is the value of the

earth? well, it's infnfinite because if we destroy the earth's environment, there is no plan "b." there is no planet "b" that we can go to. how do you put a cost on, you know, on the health of the environment? arguably you can't even do so. and in fact it's that principle that it's an infinite cost when we start talking about those sorts of scenarios that leads some people to, you know, conclude that the precautionary principle applies here, that the potentiaial impact of what we're doing is so potentially harmful to us, to other living things, to the planet that it's almost obvious that we need to mitigate this problem, that we need to take actions now to avert those catastrophic futures, potential futures.

[whoosh] [monkey screeching] [cheering and applause] clayton: [speaks s french] bonjour. how's it going, bioneers? [cheering g and applause]] yeah, yeah.h. just give me e a second hehere while i pull out my strength. woman: whoo! clayton: i, uh, i'm so happy to be here with you all today, and i'm just blown away by the people that have spoken and the incredible vision that they have shared.d. and it's my great honr to stand here on the stage before you as a bioneer, as a