The Decibel - How climate change clues are frozen in glaciers

Episode Date: November 14, 2023

There is a glacier that sits a kilometer below the highest peak within B.C.’s border, called Combatant Col. Scientists have been working on its icy surface to pull out ice cores as quickly as they can. Locked within these smooth cylinders are clues about what the region’s climate was like years ago that could help us understand today’s climate challenges.Justine Hunter is a Globe reporter based in B.C. and she explains how researchers get these precious time capsules off the top of the mountain and what scientific secrets they are looking for once the cores are safely stored in a very cold lab in Edmonton, Alta..Questions? Comments? Ideas? Email us at [e-mail]

As I'm in the helicopter, I felt like I was in an IMAX movie. It was just so spectacular to be so close to the rock and all the different angles. Justine Hunter is one of the Globe's reporters in B.C. And this summer, she got an up-close visit of the tallest peak fully within B.C.'s borders, Mount Waddington. And all along, we were just getting this stunning, close-up view of the mountain. And as you're looking out the window, you're seeing just sheer rock, ice, a sort of cloud of snow puffed up on top, and then these just incredibly sharp, raw-looking teeth sort of sticking up.

They're very wild. It feels like, you know, there's not a lot of people up there. There are no roads up here. This is a place you can get to either by hiking for several weeks or you get up there in a helicopter. Justine was flown up there to join a group of scientists who were set up just below the peak. They were on a glacier called Combatton Coal that sits between Mount Waddington and Combatton Mountain.

So it's this vast, wide glacier that kind of spills off and feeds into these other larger glaciers. And it was really kind of uncertain whether I'd make it up there or not. The weather up there is very capricious. There's no certainty, even when we finally found a helicopter, that we'd make it up there. And there was no guarantee that we'd make it back out again on our schedule. Part of the danger on this scientific mission is the weather. But there are also other threats. They really limited where people could go because there's crevasses opening up over here.

The glacier beneath your feet is actually moving slowly all the time. And so and those rock faces have, you know, you'll see little bits of rock coming down. You can get avalanches. The scientists are there to study the ice below their feet, far below their feet, because it holds information about our past, and knowing that could give us insight into our future. So today, Justine is going to explain why these glaciers are so important and how the clock is running out on our ability to study them. I'm Maina Karaman-Wilms, and this is The Decibel from The Globe and Mail.

Justine, thank you so much for being here today. Thanks for having me. So, Justine, you had this amazing opportunity to be airlifted up onto this glacier near the top of Mount Waddington in B.C. What were scientists doing up there? Well, it was a research team, and it's made up of people from research institutes from the U.S. and from Canada, got together and they spent three weeks cutting a skinny little hole in the glacier. And what they were doing is collecting ice cores, which can provide a detailed environmental record going back hundreds of years. So they're sleeping, they're eating in tents, they're melting snow for their water. And they're at three kilometers above sea level. So the air is thin. And I didn't realize that until I went for a little bit of a walk to see, peek out over this incredible spread of ice

fields below. And I realized I felt really winded. Like I'd just done something very hard. And it took me a minute to think, oh, yeah, that's why. Now, it's not the kind of elevation like at Everest where you actually have to bring in oxygen or anything, but it was enough to make a difference to how you felt when you were up there. You could feel it. Yeah. Okay. So they're up there drilling ice cores, but why do we study ice cores? Why do we do this? The inner core is really important because we can learn a lot about climate in the past in different ways. You can look at the rings of a tree, for example, and find out information about what was going on on Earth in past years. But ice cores in the polar regions preserve records that have

been in direct contact with Earth's atmosphere going back tens of thousands of years. They're very unique archives of Earth's climate history. And generally, they do this work at the poles because those cores can give us such a range of years of data. There's one core in this ice core lab in the University of Alberta that I visited, and it's 80,000 years old. So that's why we study ice cores is to find out about what's happened in Earth's history. So why is this particular set of ice cores taken from near Mount Waddington, why are they so important? It's unique because it is in a region that's further south

than any other major ice core that they've been able to obtain. And it happens to be of, I think, great importance because we're talking about the climate where we live and the watersheds where we live. And understanding those things will help us understand our future here. Again, this is a very different kind of glacier ice at Kambaten Kohl. It's high enough to be really cold, but it's also close enough to the Pacific to get this massive annual dump of snow. So then as that accumulates year after year, I think they get something

like 15 meters of snow every year dumped on, you eventually get this compressed ice. But the isolators are still thick enough. And so what they will do is show clear differences between the seasons. So if they were to get to the very bottom of the bedrock at combatant cold, they might get at the very most 1000 years of data, but it's really fine detail, very granular annual records. So you'd be able to see changes in precipitation every year, in seasonal temperatures. They could date, they hope, major wildfires, volcanic eruptions, and of course changes in the atmosphere due to pollution. So that's the really cool thing about this particular core is it's so far south, there's nothing like it. It's close to BC's biggest populations. So we're talking about information that can help us understand our changing climate at this kind of record of regional climate history here. But how does this actually work, Justine? How do the scientists, how are they pulling the ice

out from so far below? So when we got up there, there was all the little tents where people sleep. There was a cook tent. And then there was one kind of yellow sort of teepee-shaped tent where they had this special drill set up and all the equipment is in there and they're what they're doing is they rig up this drill that's kind of barrel shaped it heats up the outside heats up and as it goes down it melts a core of ice and when they have about two meters of ice they stop cut it and they lift it up there's little grappling hooks that sort of hang on to this precious block of ice. And they lift it up, carefully slide it out, package it up, mark it up, so that they keep track of exactly which one is which.

And then the ice cores drop back down. Now they're two meters further to closer to the bedrock. And then they cut the next section. And the goal is to collect a complete core right down to the bedrock. And then, you know, with each one of these cores that they've got, they cut that down to one meter, it's bagged, it's numbered, it's stored in a steel tube. They then carefully put it into this ice hut they dug out on the coal to keep them frozen until they're ready for transit. There was a core taken up when I was there from about 215 meters down. Now we're waiting for the final tally,

but they estimate that that piece of ice that came up had not seen daylight probably since the 1800s. And it was really neat to sort of be there and go, this is information from a time in British Columbia before we were really burning a lot of fossil fuels. It was seeing a piece of history kind of coming out of the ground. Yeah, it's kind of like a time capsule in some ways, right?

You're actually going back into the record here. And you mentioned 215 meters in that example, but how far down do they actually manage to drill this time? Well, they hoped to get down to bedrock at 250 meters below the surface. So that was based on ground penetrating radar that was used to map out and figure out where they should drill. But it's an imprecise science because they can't really figure out exactly what's there. So when they started drilling, they got down to close to 200 meters and they hit some kind of obstruction. And they thought, oh, you know, this is not good because they don't know what they've hit. They're pretty sure it isn't bedrock.

So they actually backed up the drill and they kind of canted it out and drilled it a bit of an angle just to get past that first obstacle. So they try this trick and they manage to get around the first obstruction. So long as it keeps recovering the weight of the drill, it's still moving down. And having gotten around this obstacle at 208 meters, we're like back in action now, which is exciting and somewhat unexpected. Like you don't often get the chance to move around an obstacle in a borehole. So it is, you've managed to completely... Yeah.

Oh, wow. We're just drilling again. This is nuts. And then they made it down to 219 meters and then they couldn't get any further. So the deepest, oldest record this far south and north America and they're so close to getting a little bit further but they couldn't go any further. So you can tell just from talking to the researcher it was a bit of distress that they had to they had to pack up at that point and say that's as much as we can get. They don't know

for sure what stopped the drill or how far from bedrock they were, but they knew that even if they had made it down another two meters, there would have been significantly more information, older information that they couldn't get. We'll be back in a minute. Okay, so they're taking out these long cylinders of ice, these cores, extracted from hundreds of meters down where you're standing on the glacier here. But I imagine, Justine, this is just the first part of actually studying these cores, right? You got to get them out, and then I guess you have to get them down the mountain, right? So how does that part of the process work?

Well, very carefully. This is expensive research. It's not easy to replicate. So they have each section of core put in a steel tube that's kept frozen until they have enough for a helicopter load. It brings each load down to its spot where there is a freezer truck standing by. And that freezer truck has got to keep running so that they've got all the cores being kept carefully stored until through the whole three-week process, they've got all the cores being kept carefully stored until through the whole three week process, they've got the full load. Then the truck is carrying those cores to Edmonton. They're driving through a landscape where there are wildfires just burning everywhere. This is

the middle of July now. Wow. So you've got a freezer truck carrying these ice cores driving through wildfires that are burning. Wow. The wildfire smoke at that point in places was so hard you could barely see some of the cars in front of you. It was a grim summer of drought and fire. And that's this backdrop to this whole process that they're trying to keep this environmental record alive to help us figure out what's going on and put these extreme weather events we're seeing into some kind of context. So, you know, there's a lot of anxiety around getting there. What if the route is blocked? What if the truck breaks down? The guy who led the team on combatant coal, this is Dr. Peter Neff from the University of Minnesota,

he told me he didn't relax until the doors closed on the cores in the ice facility at the Canadian Ice Core Lab in Edmonton, because then he knew that they were going to be kept in this special freezer at minus 40 Celsius with a backup power in case the power goes down at the University of Alberta. And then he knew that they were going to be safe. Wow. Yeah. That's a high stakes process, right? Because if you work to get those ice cores out, but then something happens on the way to the lab, like all that work is kind of for naught. And that's happened before. So they've learned from that for sure. Oh, wow. OK, so got the ice cores out.

You got them to the lab. And then I guess, how did we read ice cores? How do you know which chunks of ice correspond to which year or which era? For the preliminary analysis, Dr. Eric Steig cut off this thin strip off of the side along each side of each of the cores. The way ice compresses over time, the deepest section of the core is most valuable. It'll have the most data and of course

the oldest data. So he takes each one of those little thin strips and cuts it each into little sections and each one of those little pieces of ice is bottled individually, again carefully numbered, so they can reconstruct the precise order that the ice was brought out. And then those little bottles are brought up to melt for the first time for some of them for hundreds of years. That water is then carefully decanted each into its own little vial. And Dr. Stagg then took this kind of precious collection of water bottles back to his lab at the University of Washington. And that's where he's been doing this testing to extract just the basic information at this point. So they left combatant call with a very rough estimate. They figured they had maybe 200 years of records. But what he'll do there in

the lab is test precisely what they got from those water samples to get an age and date for those. And they'll also be looking for impurities like soot from fires and avalanche ash. But a lot of the deeper kind of analysis will come once they've figured out what they have. Wow. And you said something about how everything is kind of compressed, like as you go back further in time, it's more and more compressed. Can you explain that to me? How does that work? Well, you imagine you've got, say, 15 meters of snow dumped every year on the call. Over time, the weight of that snow dumping on and then freezing and dumping another layer and freezing, it gets heavy and it compresses down. So the deeper you go, the thinner the layers of ice. So I looked at one when I was in the ice core lab, one of the oldest

cores that they brought out. And you can clearly see these sort of thin layers, maybe a centimeter each that would represent the summer and the winter of that year. So it's now gone from 15 meters down to maybe two centimeters. So that gives you a sense of just how much closer the layers are. But the fact that you could still see those layers that far back was something that the researchers are very excited about because they can test the differences between summer and winter temperatures even, which is pretty phenomenal for these kinds of ice cores. Yeah. And I guess I'm also thinking, Justine,

because we've been talking about, you know, studying the climate here. And we know glaciers are melting because of climate change, right? So I guess I wonder how that process is affecting these kinds of studies. The reason I got to visit this glacier was because I was bugging Dr. Brian Menounos, I think for the last couple of years, at least, asking him to let me follow him on one of these research projects in person. He's a glacier expert at the University of Northern BC, where he's been studying glacier loss for years. And his team, along with the Hakai Institute, they do aerial surveys twice a year, over 800 glaciers in Western Canada. And sitting next to him in the helicopter, I'm looking around and I'm going,

wow, this is so beautiful. Look at that glacier. Look at that beautiful lake with this incredible color. And he's just sitting there and he's so glum. And he's looking at how much the ice has retreated. Now, glaciers are on the move all the time. They flow and they gain and they lose mass every year with snowfall accumulating in the winter and the summer melt. But they can do all of that and stay in balance or equilibrium is what they call. And that's not what's happening right now. We're out of balance. And so these glaciers in Western Canada have been losing tremendous amount of mass since the 1980s. And the past three years have been really bad. Dr. Menounos calculated, said just this year, just those glaciers we could see, they lost 1 billion tons of water. That's permanent loss, it's not coming back. And

that glacier I was standing on that was roughly 250 meters has the height of that glacier has dropped by about four and a half meters in the last three years. So again, you kind of think about how quickly that record, that incredible record we're now trying to access is disappearing. Yeah. And you mentioned something else, Justine, about wildfires. So I guess I'm wondering about all the way this is that wildfires are affecting this as well, and the soot from the wildfires in particular. So how exactly is that affecting the melting of glaciers?

Well, this is a kind of feedback loop that we're really just starting to appreciate. But what happens when you have these massive wildfires is that there's a layer of soot that can land on the glaciers. And then it creates kind of a dark mass and blanket, if you will. And then in the summer heat, that dark attracts more sunlight, it warms up faster, and therefore the ice is melting faster. So you can imagine how the glaciers are melting faster in part because of the fact that we've got these massive fires that are kind of warming them up. And so there's pressure on scientists to get this work done, you know, before more melting happens. But I imagine, you know, we're talking about losing a billion tons of water a year, right?

I mean, that's got to have an effect on wilderness, wildlife and people who use that water as well. Sure. And again, that one billion, that's one sort of glacier watershed we're talking about. So this is going on right across Canada with our, you know, we're worried about our permafrost. We're worried about these water sources all over around the globe. I think there's 2 billion people that rely on, you know, these glaciers for their drinking water. So it's a critical water resource for people and for wildlife and for ecosystems, both aquatic and terrestrial. And then you look at the drought we've had across Canada this year. In Western Canada, we've been consistently in a drought for about 18 months. So that makes us more susceptible to wildfires. And we've had these rivers that are

so dry that the salmon can't return, and people are scrambling to try and help salmon. So these glaciers can act as a buffer, replenishing our water supply in some of those water systems when the seasonal snowpack is gone, and that's why they're so important. Just lastly here, Justine,

what do we lose if we don't have access to this information? Well, what this project showed is that they can get very good climate records from these southern glaciers. And I know the researchers want to do more of this now in some of the other glaciers in the Columbia ice field, for example. They know they're racing against the clock to do that. But honestly, the bigger problem is that when these glaciers are gone, we've lost that process that replenishes our water supply, acts as a buffer when things are hot and dry. And we really saw a taste of that this year. We saw global heat records broken,

the fire weather right across Canada, extreme drought here in Western Canada. So those glaciers are not just a repository of kind of our climate history, but they're also critical to a livable future for our kids and grandkids. Justine, thank you so much for taking the time to speak with me today. Thanks for having me on. That's it for today. I'm Maina Karaman-Wilms. Our producers are Madeline White, Cheryl Sutherland,

and Rachel Levy-McLaughlin. David Crosby edits the show. Adrian Chung is our senior producer, and Angela Pachenza is our executive editor. Thanks so much for listening, and I'll talk to you tomorrow.