The Risk of Permafrost Thaw on People, Infrastructure & Our Future Climate

Dr. Fabrice Calmels:

There is huge areas of permafrost that contain a significant amount of organic matter. Now that the climate is warming and impacting permafrost, the problem is that it means that if you release the greenhouse gas, it will contribute to warm the atmosphere even more, and therefore, it will contribute to thaw permafrost even more. And therefore, it will be some kind of positive feedback that may really cause an issue in the future.

Michael Torrance:

Welcome to Sustainability Leaders. I'm Michael Torrance, Chief Sustainability Officer with BMO Financial Group. On this show, we will talk with leading sustainability practitioners from the corporate, investor, academic, and NGO communities to explore how this rapidly evolving field of sustainability is impacting global investment, business practices, and our world.

Speaker 3:

The views expressed here are those of the participants and not those of Bank of Montreal, it's affiliates, or subsidiaries.

George Sutherland:

Hi, I'm George Sutherland, climate change and sustainability advisor in the Bank of Montreal's Climate Institute. I'll be hosting a series of episodes, doing a dive into the different physical risks of climate change, covering topics such as flooding, permafrost thaw, wildfire, drought, extreme heat, and more, and speaking with leading experts to unpack what each of these climate risks mean to our environmental, social, and economic systems. In the second episode of this series, we're exploring the topic of permafrost thaw. Permafrost underlies approximately one quarter of the Northern hemisphere's land surface and is widespread in sub-Arctic and Arctic latitudes in Canada, Alaska, Russia, and Northern Europe. About five million people live on these permafrost landscapes and are directly impacted by current and future trends in thawing permafrost.

George Sutherland:

To put some numbers to this impact, in Canada, the cost of thawing permafrost is estimated at 1.3 billion over the next 75 years in the Northwest territories alone. In Alaska, where 85% of the land surface is underlain by permafrost, one 2015 study estimates the cost of permafrost thaw to infrastructure climbing to 1.6 billion US dollars by the end of this century under an RCP 4.5 emission pathway. And in Russia, a country where 65% of the ground is underlain by permafrost, the cost of its thaw has been estimated at more than 67 billion by mid-century. Yet, to many, permafrost thaw might still seem a distant thought, something recognized as important due to the economic impact that it has on those who live in these Northern regions, but to those of us outside these areas, permafrost thaw can seem far away from impacting our daily lives, our health, or our ways of doing business.

George Sutherland:

But the reality is that permafrost is fundamentally linked to all of us through environmental systems which operate at a global scale. That's because when ground is frozen, it prevents carbon rich organic matter from decomposing, which effectively traps large amounts of carbon in our world's permafrost. In fact, over the 23 million square kilometers, where permafrost is found, it is estimated that about 1,500 gigatons of organic carbon are stored. That's more than all of the carbon currently stored in our atmosphere. And as permafrost thaws, this carbon rich organic matter decompose and releases greenhouse gases to the atmosphere, which exacerbate the impact of climate change to everyone no matter where you live. Even if only a small portion of this appreciable store of carbon is emitted to the atmosphere, it could influence the severity of flooding, droughts, fires, and other climate extremes, which underscores the point that in a conversation about the impacts of climate change, permafrost is a globally significant part of the discussion.

George Sutherland:

And with me to unpack this subject in greater detail are two experts on this topic, Dr. Fabrice Calmels is a permafrost and geoscience research chair at the Yukon University Research Center, who has been studying permafrost thaw across the Canadian north for 20 years. His research examines the impact of permafrost thaw on landscapes, infrastructure, communities, and their traditional land. And he is currently working on permafrost vulnerability studies with the Vuntut Gwitchi First Nation and the Champagne Aishihik First Nations. He also is assessing the impact of climate change on northern highways and contributing to the development of adaptation strategies in partnership with the Yukon government.

George Sutherland:

Also joining me is Paul Murchison, executive director of major transportation with the Yukon government. Paul has more than 15 years of experience specializing in transportation and geotechnical and permafrost engineering, and oversees the development and implementation of many large multidisciplinary transportation programs, including the Yukon Resource Gateway Program, and he does so within the context of client and permafrost thaw posing mounting challenges to developing Northern infrastructure. Thank you for joining me today. Fabrice, can you describe what permafrost is, where it exists, and why it's important?

Dr. Fabrice Calmels:

So, permafrost is a thermal phenomenon because indeed it is any type of soil or ground that has a temperature at or below zero degrees Celsius for at least two consecutive years. You can find permafrost in the northern region like in Yukon and in Alaska and in Russia, but you can also find permafrost in mountain areas, so in elevation where the air temperature is cold enough to allow it to exist. Why it is important, well, it's frozen ground, and the ground is a very important part of our ecosystem and our economy, especially in Canada. You can have a lot of activities. You can have transportation, you can have hunting, you can have building housing on the ground. So, every time that you have permafrost in an area where these activities have taking place, this degradation can have an impact on any kind of activities.

George Sutherland:

Thanks, Fabrice. And Paul, do you have anything to add from a transportation perspective or from your lens?

Paul Murchison:

Yeah, George. I think when we look at how permafrost thawing that can impact transportation infrastructure in the Yukon, the first key thing to realize is over 25% of our transportation network is underlain by permafrost. A large portion of that permafrost is ice-rich, meaning there's a lot of ice in that ground. Climate change-induced permafrost thawing causes that ice to thaw, and when the ice thaws, you have a loss of volume in material under your road is that it becomes water and drains. So, what we can see is a lot of movement, which would be settlement deformation of transportation infrastructure as a result of climate change-induced permafrost thawing, and that becomes a big issue from a jurisdictional perspective as we look to having to maintain this infrastructure currently and into the future.

George Sutherland:

Fabrice, can you unpack the signs of how climate change is impacting permafrost, and what trends are observed in permafrost thought to date with a warming climate?

Dr. Fabrice Calmels:

Yes. So, permafrost is essentially a climate phenomenon. Right? Because it's based on temperature. So, it means that it's developed because atmospheric temperature cold enough induced frost in the ground. And the climate change at this time include air temperature warming, but also includes a change in the precipitation. And to have permafrost degrading, it takes one thing which is heat and air temperature rising, include warming in the permafrost, but also if you increase amount of precipitation and the amount of water in the system, this water is carrying heat that will also degrade and thaw permafrost. So, the two major impacts of climate change are those, are the increase of air temperature, but also an increase in precipitation and can be the precipitation with the water warming the ground, but also the precipitation in winter with more snow that we melt later on at spring and we'll bring heat in the system. But also, the snow has an insulating effect on permafrost. It is a blanket that covers permafrost during the winter and prevent permafrost to cool off.

George Sutherland:

So, global average temperature has increased 1.1 degree Celsius, and northern latitudes are warming at three times this global average rate. Can you speak to the increased rates of change that are being observed in permafrost thaw?

Dr. Fabrice Calmels:

I think that there is two types of change. There is a change that are slow and progressive, and this is a kind of change we have like when we are talking about settlement and the formation of thermokarst ponds or lake. And this one's always a little bit difficult to quantify. If you look at some satellite imagery and air imagery for the last 50 years, we observed that there is an increase in the formation of these ponds and lake. Permafrost temperature is a very good indicators about change. Over the year, scientists has observed that ground temperature has increased at many places in the north, and this increase in temperature seems to be accelerating this last decades.

Dr. Fabrice Calmels:

Also, with that you have the active layer, which is the layer of ground that freezes and thaw each year. That is increasing. So which means that you start to lose permafrost from the top to the bottom. So, those are very progressive and take time to develop, and maybe less catastrophic that other type of degradation such as landslides. And these landslides that we call often retrogressive thaw slump, that are the most dramatic ones that you can have, can be very fast, formed in a matter of of few years. And what we start to observe now is that there is an increase frequencies in the formation of this type of mass movement and slope.

George Sutherland:

Thanks, Fabrice. And Paul, do you have anything to add?

Paul Murchison:

What I would add is that when you speak about climate change and rate of climate change, certainly it's faster in the north, but when you look at North America, that climate change is further accelerating in the Western Arctic. So, when you look at the Yukon, we're experiencing even greater magnitudes of climate change from a warming perspective. So, what Fabrice mentioned, with respect to some geohazards and thaw slumps and some of those significant occurrences that can impact highways, bridges, airports, where we do see more frequent occurrences of geohazards, and that's that more immediate large magnitude type failures. We also are experiencing more gradual changes, which I would describe as in areas where roads may have been stable in the past, so on permafrost that was not thawing. With climate change and this warming that we're experiencing, some of these areas are becoming destabilized and we're seeing settlements occur and failures occur, smaller scale failures, more frequently in the north. So, what we're starting to see is these impacts being displayed on our network, where in past we really haven't had problems.

George Sutherland:

Thanks, Paul and Fabrice. And I'm wondering if we could unpack a little bit more about the environmental impacts of thawing permafrost.

Dr. Fabrice Calmels:

Yeah. There is huge areas of permafrost that contain a significant amount of organic matter, and when this ground is frozen, it's not an issue because it stopped any type of biological process to degrade this organic matter and induce the formation of gas, or release carbon dioxide or methane. Now that the climate is warming and impacting permafrost, the active layer is increasing, which means that some layer of ground that were frozen and containing this carbon are reactivated biologically, so degradation can develop. The problem is that it means that if you release the greenhouse gas, it'll warm up again and contribute to warm the atmosphere even more, and therefore, it will contribute to thaw permafrost even more. And therefore, it will be some kind of positive feedback that may really cause an issue in the future. So, my feeling is that [inaudible 00:14:50] a solution to that is political, I guess. It's really preventing to have more greenhouse gas in the atmosphere to trigger this mechanism.

George Sutherland:

And this positive feedback is certainly important. It's even being referred to as a carbon bomb. And the fact that this sort of language has been used to refer to this positive feedback mechanism indicates just how concerning these positive feedbacks are associated with thawing permafrost.

Dr. Fabrice Calmels:

Yes, it's true that it represents a lot of carbon that could be released in the atmosphere. To be fair, it's only when you look from the permafrost perspective that it can be an issue. Now we know with warming climate, all the ecosystem in the north will be changed, which means that, for example, the tree lines should go higher in the north and some vegetation should develop. So, it's a possibility that part of this issue is mitigated by the ecosystem itself, because by growing more vegetation, you may trap this carbon in the environment.

George Sutherland:

Thanks, Fabrice. And Paul, what sorts of environmental impacts of thawing permafrost have you observed?

Paul Murchison:

I reference back to my earlier comment about increasing frequency of geohazards, and that can lead to infrastructure failures. A road, for example, can wash out. So, there certainly are environmental impacts linked to that. There's increased sedimentation resulting in creeks, as an example, where you have more frequent geohazards, such as landslides, resulting from permafrost thaw. But that, in turn, then has significant impacts on people's ability to move throughout the territory using our network when those incidences occur.

George Sutherland:

And that's a great segue into another important topic. I'm wondering if we could expand a bit on the economic impacts of thawing permafrost.

Paul Murchison:

With the economic impacts as we look at the cost to operate transportation networks, so roads, highways, and bridges, and that operational cost is the maintenance cost, moving snow, filling potholes, grading roads, and reconstruction costs as sections of that infrastructure age. One thing that we're certainly seeing is a shift in how money is spent in areas where permafrost is thawing, maintenance costs can be up to eight times more than in areas where there is no permafrost, so we do see a significant difference in those maintenance costs. What that means when you look at transportation budgets is, under our current scenario where we've had fairly stable budgets, moving into the future with increased impacts to climate change, continuing to maintain infrastructure to the current standard will not be possible with current budgets.

Paul Murchison:

When we look at deterioration of roads as a result of permafrost thaw, very simply the roads aren't as smooth as they were before the permafrost thawed. What that means for trucking goods such as food and other materials that are needed in the north becomes more expensive because the trucks cannot move as efficiently on the network. So, there's costs not just to the taxpayers through increased spending requirements from a maintenance perspective, an operation perspective for the network, but there's also costs that are born and linked to the transportation of goods in the north as roads deteriorate.

Paul Murchison:

As permafrost thawing becomes more extensive under our highway network, those increased costs extend further, and as they extend further, then it becomes a question about where does that money come from to continue maintaining the highway network as we see more thawing permafrost impacts on our highway network. And then, on top of that, when you have to go back and start reconstructing these sections of road, the big question is, can you stabilize it, or do you just have to accept that the permafrost is thawing because the permafrost is very warm, very thaw sensitive, and there's no way to stabilize that? Som certainly, looking into the future for operating the network increase costs, and trying to look at ways to cover those increased costs are something that's going to have to be considered.

Paul Murchison:

We also are doing work, and it's been work that we've been doing with Carleton University, to develop a better understanding of how climate change and permafrost thawing result in a shift in maintenance activities. And what that means is there may be more days now out where snow removal has to occur as compared with past seasons. So, there's this really snowball effect that starts to occur when you look at all the implications and the potential for those implications to have impacts on cost to operating our network.

Paul Murchison:

When we have to spend more money to maintain a current level of service, there are decisions that may need to be made in the absence of increased funding, so you might go from that hard surface to a gravel surface because it's cheaper to maintain and operate that gravel surface. We'll certainly continue to maintain safe roads, but they not be to the same standard. You may not be able to drive as fast in the future on some of these sections of road because they're not as smooth as they used to be, so we may decrease speed limits, in addition to changing a surface. So, there's implications to try to keep the network operating safely where additional funding may not be available.

George Sutherland:

And we've been touching on this a little bit so far in our discussion, but wonder if we can shift gears to this in more earnest discussion and unpack a bit more about the social impacts of thawing permafrost.

Paul Murchison:

Socially, what that can mean for people is a lot of people in the territory use the land, I think, in traditional ways, so there's hunting, there's trapping, harvesting on the land. And that accessibility, in the future, has the potential to be impacted as a result of damaged cause to infrastructure by thawing permafrost. We've also seen other climate change impacts, and a really good example of that is in Dawson City, since the 1960s, an ice bridge has been constructed across the Yukon River. It's about a 400 meter ice bridge over the river. And what we've seen in the past 25 to 30 years is the annual number of days that ice bridge can operate decrease by about 1.75 days per year.

Paul Murchison:

And that ice bridge was constructed successfully every year without issue from the 1960s through to the winter of 2013/'14, where a portion of the river didn't freeze and additional measures needed to be taken to construct the ice bridge that year. And then, in the winters of 2016/'17, 2017/'18, and 2018/'19, we were unable to build an ice bridge due to open water in the river. So, when you look at this change, and this ice bridge provides access to a community on the other side of the river, the social impacts are significant. The overall climate change impacts can be huge for a community when you look at losing access for an entire season.

George Sutherland:

So, what gaps exist in our understanding of permafrost thaw and the impacts of this change?

Dr. Fabrice Calmels:

One thing I'm questioning myself more and more is the impact of this singular event, such as the single heat wave during the summer, or how the frequencies of these freak events may impact permafrost. Same thing with precipitation. Sometimes we have relatively dry, the usual dry Yukon summer, but less and less. Sometimes we have events where it rains a lot for a few days, sometime a few weeks, and it has an impact on permafrost. We still have the time to grasp how this sequence of singular events that become more and more frequent may impact permafrost.

Paul Murchison:

Fabrice mentioned a number of the factors that impact permafrost: it's a dry season versus a wet season, it's a hot season versus a cool season. But then, the piece that you layer on top of that is you add a piece of infrastructure that we built on top of the permafrost that, again, further complicates that scenario because the road on the permafrost affects permafrost behavior, as well. It can act as a heat sink and determining how much heat that road will put into the ground compared to what naturally was put into the ground and how that impacts groundwater flow and how that impacts all these other factors is very complex. And being able to understand that, to figure out how to adapt to climate change and how to stabilize highways becomes a much more complicated scenario than standard highway construction.

Dr. Fabrice Calmels:

Permafrost science is not a very unique body of research. Right? Ground is connected to everything. It's very challenging to know how we will manage all this whole balance, the fact that we need to preserve permafrost to prevent damaging the infrastructure. But on another end, we have to let it go. If the climate is not on our side, we just cannot keep permafrost going artificially.

George Sutherland:

So, the Intergovernmental Panel on Climate Change recently released a report which found that due to historic and current greenhouse gas emissions, a certain amount of climate change is locked in, and that's to say is irreversible on the time scale of centuries to come, which highlights the need for adaptation measures which reduce vulnerability to the impacts of climate change. So, what does adaptation to permafrost thaw look like, and how prepared are we to manage this risk?

Paul Murchison:

Going back to 2007/2008, we built a permafrost test site. That permafrost test site included 12 unique approaches to highway construction and permafrost terrain. And the purpose of that test site was to facilitate fundamental research around this test site, as well as getting, from an applied perspective, get a better understanding of how these sections could perform on thaw sensitive permafrost. That work spawned numerous studies, and we learned a lot. And things that may seem very simple like what happens to groundwater as it flows under the highway, and what we found is groundwater temperatures could decrease by as much as two degrees Celsius from one side of the highway to the other side of the highway down gradient, indicating a amount of heat going from the groundwater into the permafrost, inducing additional permafrost thaw. So, lots of research was done there just to give us an idea of what type of approaches can we use to adapt our highway construction to provide stable highways in the face of climate change and thawing permafrost.

Paul Murchison:

And then some of the work stemming from that with Fabrice we looked at a study on a portion of our highway network where we were trying to understand the vulnerability of that highway section to permafrost thaw. And then by looking at that vulnerability, combined with the knowledge that we were gaining from our permafrost test site, we're put into a position where we can decide which sections we're likely able to stabilize and then move from a small test section to a larger test section. And then, two years ago, we constructed a relatively large test section utilizing thermosiphons to keep some massive ground ice frozen under a segment of our highway.

Paul Murchison:

Now, when I talk about thermosiphon and buried ground ice, on this longest section of highway a few hundred meters, we have pure ice, that's ice out of your ice cube tray in your house, up to eight meters thick. So, when you think about thawing as that ice thaws that would mean, over time, the highway would settle eight meters. So, it was deemed to be a suitable site for an approach to stabilizing the highway. We installed thermosiphons which passively extract heat from the ground through the winter. We've found now after looking at the data that those thermosiphons are successfully keeping the ground cool at that location, and as a result, we're expecting that at that larger test site that we've constructed that we are in a position to say that we are stabilizing the permafrost.

Paul Murchison:

So, what do things look like? We can't put thermosiphons everywhere. We're talking a lot of money to do that. That's site specific extreme example of a very expensive approach to highway construction, but we are getting into a better position to have a better understanding of what our risk is throughout our network and then looking at the different approaches based on our knowledge from the test site and other work that we've done to make some decisions about how to best deal with the risk associated with climate change and permafrost thaw resulting from climate change.

George Sutherland:

So, what are some of the challenges faced in mitigating exposure to permafrost thaw?

Dr. Fabrice Calmels:

A lot of activities are done at the road level and at the road site to prevent any damage to the road, but more and more now we have to look outside of the road to anticipate the damage that make that permafrost degradation may cause to the road. And when I think about that, we have a site where we have a landslide developing, they are progressing in direction of the road, and this one is challenging. Right? Because it's not about building a better road, about building the road that does not impact permafrost, it's about a natural phenomenon that occur in the field and that may come to impact your infrastructure.

George Sutherland:

And Paul, was there anything from a infrastructure perspective that you would want to add?

Paul Murchison:

Throughout the Yukon, a lot of our infrastructure is trending towards end of useful life from a lifecycle perspective. So, what we're looking at is, when we go to reconstruct, rehabilitate that aging infrastructure, what approach do we use? And I mentioned before the use of vulnerability studies. But there's also another issue which is really important, and that is when you look at designing transportation infrastructure, designing a road over permafrost, when you look at the industry and the number of people in industry, the number of people in academia, and even the number of people working for governments that deal with this, we're dealing with a very small subset of practitioners, engineers, technicians, and academic experts.

Paul Murchison:

So, as we look at getting resources to deal with design and construction and how to do that, a big challenge is finding the people that have the expertise and understanding to be able to successfully implement work. Because there's not many people in the north and there's not many people that specialize in permafrost engineering and permafrost science, so we deal with a very small community and, as a result, very limited resources when we look at options to our hiring people to help us solve the issues that we have.

George Sutherland:

What are the practical steps to minimize exposure to risks of permafrost thaw?

Dr. Fabrice Calmels:

Well, we have a lot of examples of buildings that were designed to be built and to perform on permafrost that failed anyway, and there is a few examples. There is schools, recreation center, and it's all across the north. So, it just proves that building on permafrost is very challenging and very demanding, and climate change will make it even harder. Can people get insured for permafrost to impacting their home? The answer is no. Nobody will ensure you for permafrost damage, my understanding. And everything that is as so much certainties are linked to also the evolution of the climate, I don't think that there is a lot of people that take the risk.

Dr. Fabrice Calmels:

There is a very well-known way to build house on permafrost. There is even some guides that you can find that has been developed in Northwest Territory, for example, for homeowner for a house on permafrost. There is good practices that you can apply. And there is a lot of also very successful house built on permafrost, simple techniques like a building on the pad of gravel. Okay? So, permafrost may raise and [inaudible 00:39:50] a bit in the gravel pad and ensure it a bit more stability to the building. I think your building above the ground on [inaudible 00:39:59] or on tripods, for example, are great to help cool down permafrost because the winter air can go between the house and the ground and allow permafrost to cool. The price is high. You don't build this type of building cheap. And also, the price is high because of the building itself, the design of the building, but also because we are living in the north. Right? So, think about a material shortage such as we had this year about COVID and think about the cost of transportation, and it add up another issue. Right?

Paul Murchison:

From my perspective With highways, you can't really minimize your exposure because the highway's already on permafrost, for example. But I think a lot of the work that we've been doing in the work that we'll continue to do with people like Fabrice, academic experts, is understand the risk. That's climate change impact assessments linked to our projects so we can better understand and make sure we're quantifying the potential risks and then making decisions about our highway infrastructure that consider those risks.

Dr. Fabrice Calmels:

When things also to minimize the exposure to the risk of permafrost was one thing that we have done at Yukon University, which was to produce permafrost as a maps for the communities. So, you go into communities, you study the geology, you are studying the sites, and you are mapping where are the permafrost area? Where are the area where there is no permafrost? Where are the areas where we may have a mix, but it's not so bad. You may still build on it if you use some specific techniques. And you produce these maps so the community leaders can use them to develop their community and avoid the bad spot if they can or choose the proper way to build on some of areas where there is permafrost in such a way that the community is developed in a more friendly approach with permafrost.

George Sutherland:

Thank you to Dr. Fabrice Calmels and Paul Murchison for joining me to share your expertise on the environmental drivers and social and economic challenges associated with permafrost thaw and, importantly, the practical actions that can be taken to build resiliency in our socioeconomic systems to minimize exposure to this climate risk.

Dr. Fabrice Calmels:

Well, thanks to you.

Paul Murchison:

Thanks for inviting me to be a part of this important conversation, George.

George Sutherland:

And thank you to our listeners, and stay tuned to learn more about how climate change intersects our social and financial systems as I continue this series of episodes, offering a deep dive into topics including flooding, wildfire, extreme heat, and more.

Michael Torrance:

Thanks for listening to Sustainability Leaders. This podcast is presented by BMO Financial Group. To access all the resources we discussed in today's episode, and to see our other podcasts, visit us at bmo.com/sustainabilityleaders. You can listen and subscribe free to our show on Apple Podcasts or your favorite podcast provider, and we'll greatly appreciate a rating and review and any feedback that you might have. Our show and resources are produced with support from BMO's marketing team and Puddle Creative. Until next time, I'm Michael Torrance, have a great week.

Speaker 3:

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