 I'm Luke Copland at the University of Ottawa. I hold the University Research Chair here in Glaceology and I study glacier ice shelf and sea ice changes mainly in the Canadian high arctic. So I work on research on glaciers mainly in the Canadian high arctic and looking at how the glaciers are changing. We're also looking at how the ocean is changing as well. So how we get changes in icebergs to the oceans for example, changes in sea ice, changes in ice shells in the Canadian arctic. When we think of ice shells, we most typically think of Antarctic ice shells and they make up a large part of the Antarctic coastline. In the arctic, ice shells are much rarer and in the arctic the largest number of remaining ice shells, largest area of remaining ice shells is on Northern Ellesmore Island in the Canadian arctic and what I'm looking at is how those ice shells are changing over time. If we look back at about a decade ago in 2005, we had just over a thousand square kilometers worth of ice shelf left on Northern Ellesmore Island. If we look at those numbers today, there's just over 500 square kilometers. So we've lost roughly half of all ice shells in the last, less than the last decade. If you think of what makes up ice shells, ice shells are that interaction between the ice that flows off the land and the ocean. Certain places that are warmer, some places like Alaska for example, where glaciers reach the ocean, they break pieces off the end and they produce icebergs and there's no, there's no extension of that glacier can add into the ocean in a sense. In places that are very, very cold, when that ice reaches the ocean and interacts with sea ice, the glaciers don't break off and produce icebergs right away. They become preserved and fill up fjords basically. Some of the ice in the fjords is made up from glacier ice. Part of it is also made up from very, very old sea ice that becomes very, very thick over time. It grows both from freezing underneath and accumulation of snow up on top and together they fill up the fjords and the so, a field that's essentially full of ice is what we would call an ice shell from Northern Ellesmere and that's what we've been losing dramatically in the last decade or so. Yeah, when we look at the data, it seems that there's a number of different things that are happening there. We're seeing quite a rapid warming in the climate, so we've reconstructed temperatures back since the 1940s. The climate in that area is warming at about half a degree Celsius per decade. What's interesting when we look at the numbers is that, when we break it down by season, we're not seeing even warming in each season. We're seeing in the recent past a lot of warming in the winter and not actually that much warming in the summer. For an ice shelf, an ice shelf cares about summer temperatures because it melts it but also cares about winter temperatures because the winter temperatures essentially allow it to recover from summer melt it seems. It seems that in the recent past and the last decade we've seen a rapid warming in winter temperatures. It's a lot less intense for the cold today than it was in the past. It means that those ice shelves, they can't freeze on that ocean water on their other sides anymore. The melt that occurs and warms them up in the summer that heat doesn't get removed from the ice shelf in the winter so easily anymore. So I think when the summer arrives now, instead of the ice having to be warmed up before that matter will start, that warming begins much earlier in the summer because it's not as cold in the winter anymore. So the story I think in part for the ice shelves is the fact we've seen this rapid warming particularly in the winter in the recent past and the other big factor that we've seen is big changes to the sea ice. So we've all heard about the changes to the reduction in the extent of sea ice in the Arctic Ocean and in the past we'd have what we would call multi-year land fast sea ice that would be held up against the front of the ice shelves and that ice would typically be anywhere up to a few decades old and that would really be acts as a protective fringe against the ice shelves. It would protect the ice shelves from the effect of wind and waves for example and heat from the ocean water but in the recent past we've lost that multi-year sea ice and it seems as a response the ice shelves don't have that protection at their fronts anymore and so they're also breaking up in relation to that too. It's likely the ice shelves have been there for the last around 5,000 years or so at least and so it seems that within the last four and a half to 5,000 years this is the first time that we've seen the loss of those ice shelves in that time. So this is based on the dating of particularly whale bones and sediments which people have recovered at the back of the ice shelves which tells you that there must have been open water to allow that material to get there in the past. Yeah it's very difficult to know what happened before that so it's yeah it's very likely that when we had the last glacial period so 18,000 years ago that the ice shelves were there. So it seems that they we did lose them in the past it seems so around 5,000 years ago they were gone and presumably before 5,000 years ago they were there they were present at the end of the last glacial period but the best dating that we have gives us that kind of five to four and a half thousand year date for when the most recent ice shelves formed. The short answer is Arctic ice shelves have contributed nothing to sea level rise so Arctic ice shelves are very much like sea ice that they're already floating in the ocean so if you change if you melt them you don't actually change the water level you have to move the ice of course off the land into the ocean to change the sea level so yeah for ice shelves it does make a difference to sea level rise. When we look at glaciers globally the general pattern that we're seeing for glaciers and this includes glaciers ice caps and ice sheets as a general retreat and melt of those features that pattern is pretty true wherever you look in the world whether you look in New Zealand and the European Alps in Norway for example or those locations are losing their ice mass over time but when we say that the the losses that we're seeing aren't always even either with elevation or with location exactly most places we're losing mass but there are some locations where we gain mass as well. When we look at the greener ice sheet it the responses that we see are very different at different altitudes a high altitude above 2,000 meters we're gaining mass at low altitude we're losing mass and both of those are due to warming of the climate and it sounds a bit strange to say that at first but when you warm the climate you're doing two things one you're warming the climate which obviously allows you to melt more ice so that's the obvious factor that we that most people think about the other factor that a warming climate does is that it increases the amount of in the amount of evaporation that we have from the oceans and therefore increases precipitation so in the end the way that the glacier responds it's that balance between well is it increased melting that wins out or is it increased precipitation that wins out in most locations around the world it's the increased melting that wins out but in places which are already very very cold if you warm those places say the center of the of the greener ice sheet from a mean annual temperature of minus 20 to perhaps minus 15 is still a dramatic warming but you're not really changing the melt very much but when you warm those areas you have increased precipitation so in those situations we are increasing the mass because we're having more snow falling on the surface but that's due to warming the same way that the mountains due to warming at low elevations so we see this essentially a particular pattern in Greenland and also a pattern that we're seeing in parts of Antarctica too particularly in east Antarctica very high altitudes so it's a balance between the melting and the snow accumulation that defines what we see in the end so when we when we look at Greenland and there's been dramatic mass losses and there's mass loss mass losses seem to be accelerating in the last decade to two decades so we're seeing slight mass gains at high elevations in Greenland the very high altitude areas above 2000 meters but those mass gains are nowhere near large enough to offset the the losses that we're seeing at occurring at low elevations we've seen dramatic retreats in the length of the glaciers in Greenland dramatic accelerations of the ice as well and and if you're looking at the current in terms of the current numbers of the current amount of mass that we're losing from the Greenland ice sheet it's about three to four hundred gigatons per year at the moment and that's roughly doubled in the last 10 to 20 years or so so it's a dramatic negative mass balance for Greenland it seems that a very important factor for ice motion is the amount of water that gets to the glacier bed because if the water gets to the glacier bed it lubricates the glacier bed and then of course that allows the ice to move more quickly and so the increased melting that we're seeing on the surface of the Greenland ice sheet of course is producing more lakes on the surface more melt more rivers on the surface and it seems that that water is making its way through the ice sheet in places the ice is a thousand two thousand meters thick it's making its way all the way through the ice to the base of the ice sheet and that seems to be a large reason why we're seeing acceleration of the glaciers it's a base of lubrication so it seems that much of it is driven by this kind of upstream melt input from higher up and also there's also some evidence that's being driven from changes at the Termini too that we're seeing in warming of the ocean coming into the fjords in Greenland that's melted the kind of underside of these glaciers that's reduced the what we call the back stress the amount of stress that's holding the ice back and actually thin their ice as the glaciers start retreating there's not as much there to hold them back anymore so they start accelerating so part of it I think is coming from upstream but part of it's coming from downstream as well if you think of glaciers in terms of water supplies of course on the big ice sheets that they're not really a factor but when we think of of mountain glaciers particularly in areas close to communities and particularly areas which are close to communities where they're where the lower elevations very dry so good examples are Peru for example Alberta the east side of the rocky mountains that what glaciers do is that they act as sponges basically so in the winter they hold that snow that falls and then they release that snow in the dry time of the year which is typically the summer so what glaciers do is they tend to even out the annual precipitation that falls and essentially allow areas to carry on to have agriculture for example in the summer when otherwise there'd be areas that are very very dry when there's glaciers there they even out that water flow and allow rivers to flow for the entire summer if the glaciers aren't there we're seeing this a little bit in in Alberta in the Rockies that we see changes in the in hydrographs over time we get in locations when we lose the glaciers we get much more peaked hydrographs occurring in the spring so much more rapid runoff as the snow melts in the winter would end the summer that supply becomes depleted there's no ice left there's no snow left and then you get much drier summers instead it really shifts the hydrograph to being earlier in the summer when we think of the impacts of these water supplies so in some locations there's direct impacts on water supplies for drinking water so we see this in the Himalayas a little bit in the Alps for example I think the biggest impact is on agriculture because if you think of the the prairies that stretch east from the Rockies there's huge areas that are fed by the by the rivers that flow from the Rockies so I think the biggest impacts are really on agriculture and that sustainability in areas which are now becoming very very warmer in the summer 30 35 degrees isn't that unusual in the prairies in Alberta in the summer and if you lose that water supply then the crops drying out there just simply isn't the water there to to water them so so when we look at the Himalayas there there's some some very interesting responses that we've seen recently and there's been big differences between the area in the western Himalayas we call this the current quorum on the border between kind of Pakistan Afghanistan China in that area we've actually seen some increases in in mass glacier mass recently so the glaciers seem to be advancing we're seeing more surges tells us that glaciers are more active we seem to be seeing an increase in mass over time and that's very different to what we've been seeing in the last decade or two for the eastern Himalayas and areas like the pool for example there the glaciers that we're seeing rapid retreat in areas around Everest for example so in the western Himalayas it seems to be tied into changes on the patterns of the monsoon so it goes back to the idea that as we're warming the climate we're pulling more moisture into the atmosphere so for the monsoon that's driving the monsoon and making that monsoon perhaps more intense and pushing that monsoon rain further in land today than it happened in the past and it seems that the western Himalayas this is an area in the current quorum where the monsoon frequently wouldn't really get too very much in the past and it seems that as we're warming the climate we're making the monsoon perhaps more intense and now that moisture is pushing in further than they did before and now allowing a lot of late summer snowfall in these areas and that's been I think part of the reason why we're seeing an increase in the size of the glaciers in the western Himalayas in the current quorum much more than we're seeing really melting occurring in the eastern Himalayas I think when we look at the Himalayas the story is really very different it's kind of difficult to make a generalization for the entire Himalayas I think on average when you average out all the mass balance we're losing mass but it's a very different story the eastern Himalayas we're rapidly losing glaciers there's big concerns about glacier like outburst floods for example as new lakes are being produced by glaciers and those are those floods might then damage downstream communities and areas like the pool for example in eastern Himalayas we're seeing lots of losses but in the western Himalayas we're not seeing those same kinds of losses it's not clear if there's numbers exactly balanced out but it's a very different story in the two different locations so so when we look at the Antarctic ice sheet we we often hear about it as being one ice sheet but it's really two separate ice sheets separated by a very large mountain range called the trans-antarctic mountains so east Antarctica is an ice sheet that's grounded entirely above sea level what that means is that if we would melt the entire east Antarctic ice sheet there would be land left above the ocean surface the ice in east Antarctica is about four kilometers thick as the thickest ice we have in the world if we look at west Antarctica it's a very very different situation in west Antarctica there the ice is thinner a kilometer or two and it's grounded below sea level so what that means is if you took away the ice from west Antarctica much of the area would just be islands basically the the ocean would come into where the ice is right now so when we look at the changes for those areas the the changes that we've been seeing recently are very very different and have I think very different potential impacts so in east Antarctica it's very high and it's been pretty stable in some years or some decades we seem to see positive mass violence in some places negative mass violence in other places but not particularly big changes and not really in these significant trends when we look at west Antarctica the story is very very different and in particular there's an area in west Antarctica called the Amundsen Sea Embayment this is the only part of west Antarctica that isn't fringed by an ice shelf so it seems that the ice shelves for the other parts of west Antarctica kind of stabilize those locations but the Amundsen Sea faces the ocean directly and you have these very very large glaciers that reach the ocean and when we're looking when we've looked at the changes in elevations for those glaciers in the last decade or two we're seeing dramatic thinning for those glaciers thinning up to 10 meters per year these are areas where we see very very little surface melting we can melt ice at maybe a meter to meters per year and that part of the world from the surface but we're thinning it by nine meters per year so the question is what's causing that thinning it seems that there's two factors that are causing that thinning one is the acceleration of the ice so as you speed the ice up it will thin it dynamically is what we call it and the other way is that for that ice there's no evidence that there's in the last few years that we have large areas of ocean water that can they can extend far inland beneath where those glaciers are so it seems that there's melting occurring on the underside of those glaciers too so it's not the story there's we're losing lots of mass from the Amundsen sea region of west Antarctica but that hasn't really been driven by surface melt it's driven by basal melt and this acceleration process there's some evidence at least away from Antarctica that we're seeing quite clear warming over time so down to many hundred meters of depth beneath the surface one of the big issues for west for this region of west Antarctica the Amundsen Sea region is that it's really the most remote part of Antarctica that we have there's no basis in this area so we've started you know working there the last 10 20 years but we don't have that long-term historical record to know what was there before so it's hard to know if we are seeing warming of the ocean area we're seeing warming for sure elsewhere in the southern ocean but for that particular region it's a bit difficult to know yeah when we look at Antarctic sea ice it's clear that we've seen gradual increases in the amount of Antarctic sea ice in the recent past and this is very a very different story to the Arctic so in the Arctic we've seen rapid losses but the Antarctic we are seeing gains over time it seems that there's a couple of mechanisms and perhaps many other ones that explain this the two of the mechanisms that I'm familiar with is one it seems that there's been an increase in wind away from the continent so that that wind kind of does two things one it pushes the ice further away from the continent so it makes it extend further north than it ever did in the past and the second thing that it does is that when it pushes ice away from the continent in the winter then areas of cold water which are adjacent to the continent become ice factories essentially and so more new ice is being produced all the time as the winds are increasing there's debates as to what's causing that wind to increase exactly one of the debates is is that it might be due to warming that as we're seeing increased in temperature in changes in temperatures that are increasing between the continent and the surrounding ocean that's driving increased winds and so these increased winds are pushing the ice away from the coast the other thing they're doing for the ice is allowing it to ridge and become thicker by pushing one piece of ice over the top of another piece of ice and that's a way to thicken the ice and allow it to then last longer through the following summer so when we look at the latest IPCC projections they tell us that by about 2060 we should expect global sea level to rise by about 0.25 meters and by about half a meter by the year 2100 when we look at the the causes for that sea level rise it seems that glaciers and ice sheets are becoming increasingly important and the projections of their contribution have really increased in the last well particularly since the last couple of IPCC reports and I think really the major reason for that is that now we're understanding glacier dynamics much better so in the past we just thought of global sea level rise from glaciers and ice sheets in terms of just melting that simply if we melted the ice sheets this is how long it would take to rise at global sea level but we now realize that it's not just that simple process that if we start thinning for example the wasentatic ice sheeting places that will allow it to flow much more quickly same thing in Greenland too that when we're accelerating the glaciers it's a much more efficient and much quicker way to get rid of ice by accelerating it into the oceans and it is simply by melting it so that's one of the reasons why when we look at the IPCC projections that they really increased in the recent past because now we're thinking of ice dynamics in addition to just glacier mass balance there's some debate I mean the half a meter that the IPCC is projecting by the year 2100 there's been many papers which are suggested that's actually an underestimate I've seen some papers in the last couple years which are suggested anywhere from 0.8 to 2 meters sea level rise by the year 2100 and when you look at the IPCC report I think the IPCC is very conservative in terms of the numbers that they give they don't like to overestimate what they're doing if you take the kind of worst-case estimates of glaciers accelerating and losing this ice through an acceleration of the ice to the oceans there's many estimates that are higher than the IPCC IPCC numbers yeah I think when we look at the Arctic sea ice then it's clear we do see big variations from one year to the next I mean it's if you think of the weather from one week to the next we see big variations in the weather sometimes it's some weeks it's warmer next week it's cold but when you look at the what's important to look at for sea ice is the long-term trend yeah for sure we see ups and downs but we see a very very clear strong negative amount of sea ice in the Arctic Ocean a big decrease through time so yeah for sure some years are high some years are low but it's that long-term pattern that's the important one to look at so I really started working on glaciers I was an undergraduate at the time in the UK I started working just as a field assistant on a glacier project in Switzerland and then thought this is pretty neat and actually living in Britain never been to a glacier before and then went from there I did my masters in the States and PhD in Canada I started looking moving away from just kind of small valley glaciers into the larger ice caps in the Arctic and the Antarctic and then it's kind of snowballed from there in a sense so I think something that I try and do when I speak to the media is to I think stay very honest with the data and to I kind of see myself as being a journalist in the sense is that I want to report the facts of what's happening without any kind of interpretation or I don't want to tell you if you should care about the facts or if you should you know care about what should change what I want to do is to present the facts of how the ice is changing then it's up to you to believe whether it's climate change or whether should you change carbon emissions to have an effect on this I don't want to tell you this I want to be independent and give you the facts and then let people decide themselves what to do I think you have to tour a fine line that's I mean of course you want to you know provide the message of what's happening and you know have your own personal opinions in terms of I think you know what scientists should do in terms of you know trying to reduce the effects of climate change but but I think it's important to be independent and to and to give the facts of what they are without you know that kind of emotional interpretation they can have sometimes and let people decide themselves what they want to do with those facts I think really the biggest questions which have really become to the fore in the last decade or so is is how the big ice sheets are changing it's really amazing that in the 1990s when I was working my PhD we knew virtually nothing about Greenland or Antarctica we hadn't even imaged the interior parts of Antarctica because it was so far so far south so I think the most interesting scientific issues that we've seen really developed in the last decade or two are the changes to the big ice sheets and that's really come from a development of remote sensing so in the 1990s we hardly had any satellite images of the big ice sheets particularly in the interior parts and since the late 1990s and early 2000s we've had a dramatic increase in how we can actually understand how those big ice sheets are changing and that's really been kind of given us that that big scale perspective of what we need to understand how that much ice is changing in the past you had to rely on kind of spot measurements from a few locations but to get that really big regional picture you need remote sensing and that's been the huge development that we've seen in the last decade or two decades and that's really revolutionized what's our understanding of how these big ice sheets are changing yeah I think when I chat to people who don't accept science well I'm not sure of I haven't spoken to many people who don't really accept the science I think people don't always accept the interpretations from the science I think it's it's very hard it's almost impossible to argue that we aren't seeing climate change I mean when we look at really every weather every climate station in the world when we look at the glaciers the permafrost it's all telling us the same thing that climate is changing I think the the question that I come up against sometimes is well should we care about it I mean the world's gone through for sure it's gone through similar temperature changes in the past the world's done fine in the past why should we care about it today I think it's I don't see many much debate about the fact that things are changing I think it's more of a question of whether we should care about the fact that they are changing I think it's just I think in a sense as a scientist you want to keep it simple and just present the facts you know without that kind of an emotional interpretation and I think if you present the facts and make it clear that it's you know not one single weather station that's showing you one pattern if you talk about all the different sources of information that we have whether it's from sea ice glaciers permafrost snow weather stations or kinds of records then they're all pointing in the same direction basically you know I think I find that when people are asking about climate change as climate change real then then frequently you can ask people living in Ottawa for example and ask them well you know were the winters that you experienced when you were a kid different from what we see right now you know was this did you skate for longer was there more snow and I think everyone says yes there was I mean clearly the winters the people experienced today are very different to what they were 30 40 years ago and I think when you put it in that personal perspective and people think back you know and tell stories of these awful winters that happened 50 years ago and snow dressed the size of houses and this kind of stuff when you put it on that personal perspective for them then they can start to understand that things really are changing people argue well we've seen you know the climate be much warmer in the past and then but then the big difference today is that we in the past there weren't seven billion people living on the planet and there weren't huge cities next door to the ocean that are built for a sea level that existed 100 years ago pretty much if you think of New Orleans New York London Venice all these cities around the world with millions of people living inside them are designed for a past climate in a sense so yeah for sure we've seen climate change in the past but there weren't seven billion people living on the planet when that happened and so I think that's the difference today is that in a sense it doesn't even matter what causes the climate change maybe maybe you want to argue that it's all natural change but still the climate's changing and still it's going to have impacts so whether you care about the cause of it is still will have those impacts down the road for things like changes in the global sea level