Why are peatlands the "superheroes" of carbon storage?

Bertie talked to renowned peatland expert Professor Roxane Andersen, of the University of Highlands & Islands, the Environmental Research Institute, and the Flow Country Research Hub.

They talked about the Flow Country in Scotland, her research on restoration, monitoring, and peatland fires, and more generally about why peatlands are so important for climate mitigation.

After our podcast last year with Ed Struzik, listeners got in touch to say they wanted more content on peatlands, especially covering the science! We reached out to Professor Andersen, and were delighted she agreed to come on the show: do get in touch with recommendations or feedback, if there is anything you would like to hear about. We love hearing from you all.

Further reading from this episode:

- Read about the InSAR monitoring technology here, and in even more detail here!
- Read about the FireBlanket project here
- Read about the damaging afforestation on peatlands in the UK in the 1970s and 1980s here
- Read about the Flow Country here, including the application to make it a UNESCO world heritage site

Click here to visit The Future Unrefined, our curated collection of articles and podcasts on raw materials and extraction.

Find more podcasts and articles at www.landclimate.org

Transcript

Bertie Harrison-Broninski: 0:06

Hello and welcome to the Economy, Land and Climate podcast. My name is Bertie Harrison-Broninski, I'm an assistant editor here at ELCI and today I'm talking to world renowned peatland expert Roxane Andersen from Thurso in the very northern parts of Scotland in the UK. Roxane is Professor of Peatland Science at the University of the Highlands and Islands. She's leads research on carbon water and climate at the Environmental Research Institute, and she coordinates the Flow Country Research Hub. We're going to be talking about the flow country in Scotland, but also more generally about the science of peatland, carbon sequestration and storage.

Roxane: 0:42

Yes, we can reinstate carbon sequestration in short amount of time, but the carbon that is lost is irrecoverable. We will not recover the carbon that is lost by degraded peatlands in our lifetime and probably not in our children's. This is really long term thinking.

Bertie Harrison-Broninski: 0:58

I began by asking Roxane to explain a little bit about peatlands, what they are and why they're important in greenhouse gas terms.

Roxane: 1:05

Peatlands are ecosystems that are found around the globe but are particularly concentrated in the northern hemisphere. And they're basically ecosystems where plants sequester carbon through the atmosphere by taking out carbon dioxide through photosynthesis, and build up plant material, but that plant material doesn't decompose fully because the conditions where those ecosystems develop tend to be wet, cold, and often have those conditions that prevent that organic matter from decomposing. The accumulation of that organic matter, plant material over time builds layers of dead organic matter that is called peat. So peatlands are those ecosystems where the plant matters have accumulated in those kinds of peat layers over time. Typically, peatlands have accumulated these dead organic matter there for a very, very long time. And in the northern hemisphere, they have done so since the last glacial retreat. So some peatlands have accumulated peat continuously for thousands of years. And that is one of the reasons why peatlands are so important for carbon sequestration and storage. Despite covering only about 3% of the terrestrial land mass, peatlands store up to a third of the global soil carbon stocks. And wihle they don't take a lot of carbon dioxide from the atmosphere on a daily or annual basis, they do so continuously over a very long periods of time. So because of that they're a net sink of carbon and they contribute to that reduction of carbon dioxide from the atmosphere and the long term storage of that carbon in the soil where it just stays and remains there as long as the peatlands are not disturbed or the climate doesn't change too much.

Bertie Harrison-Broninski: 2:58

Just seeing the figure that it's nearly as much carbon stored in peatlands, as is currently in our atmosphere really kind of brought it home.

Roxane: 3:07

Pealands are really the kind of superheroes of carbon storage for their size, the completely disproportionate amount of carbon that they store for the area that they cover is really, really staggering.

Bertie Harrison-Broninski: 3:19

Just to kind of finish off that bit;

Roxane: 3:28

Absolutely. So the main thing about peatlands is that when they're left undisturbed, and when these conditions are I'm right in thinking that when they're drained or damaged, they maintained where the carbon accumulated by the plant can be can then start to emit all of that carbon, right? So they're a stored and sequestered over the long time, they'll just continue risk as well as an asset? ticking along storing carbon. However, the disruption of this condition in particular through drainage will change all of the processes that enable that storage to take place and in particular will start to accelerate the decomposition of the organic matter that is currently stored below ground and start to release more carbon out of the atmosphere than can be sequestered through the photosynthesis. In other words, degraded peatland and particularly through drainage will shift from being a net sink to being a net source. And the worrying thing is that globally, we don't need to drain a lot of our peatlands to turn the whole system globally from a net sink to a net source. So even the drainage of a small proportion of the peatland can shift the entire way that the whole system is functioning. And of course, if that carbon that was stored for a very, very long time is released back into the atmosphere, instead of helping us with climate change, degraded peatland can contribute to climate change by fueling that CO2 buildup into the atmosphere.

Bertie Harrison-Broninski: 4:45

A couple of guests on this podcast have praised the work being done in the flow country. One of them was Ed Struzik, the author who writes about peatlands and the other was Liz Carlisle who writes about regenerative farming. Could you give us a little intro to the Flow Country specifically? What makes it different? What can the rest of the world learn from it?

Roxane: 5:02

The Flow Country is the current name that is given to an area of peatland in the far north of Scotland covering most of the counties of Caithness and Sutherland. And the Flow Country is globally significant because it's a particular type of peatland that are called blanket bog. Blanket bogs can only form where the climate is very, very wet, consistently cold throughout the year. So they tend to form in islands or coastal areas at high latitudes. So in the north and the south and southern hemisphere. So of all the peatlands in the world, only about 3% of those are blanket bogs. But the Flow Country is one big area, the largest continuous expansive blanket bog, at least in Europe, probably in the world. And it's certainly one of the areas that is currently in the best conditions from the blanket bogs in the world. For that reason, there's been quite a lot of work in the last decade, leading up to the Flow Country being nominated as a potential candidate for a UNESCO World Heritage Site. So the Flow Country are a complex mosaic of peat blanket bogs that have been impacted by people for a very long time, just because there's been people in the UK for a very long time. There's a combination of areas that are in so very, very good condition. But areas that have been degraded historically through combination of drainage, grazing, burning, but also large scale afforestation that happened particularly intensively in the'70s and '80s. But one thing that perhaps sets the Flow Country apart from other areas, is the amount of restoration work that has been taking place to try to bring those peatlands back into the best possible condition and improve their resilience. And that's been achieved through a very large coordinated effort by a very large number of organisations working together, combining the practice or the actual restoration on the ground, with the science, the kind of underpinning knowledge, expansion and evidence, building up the evidence to support the restoration and the protection of these habitats. The alignment of these activities is quite unique, you know, the fact that the research is helping and supporting the practice, but also that the practice is working very much alongside the policy and the science altogether, is quite unique, and is probably a good model in terms of taking things forward and making change happen.

Bertie Harrison-Broninski: 7:26

I know it's a little bit reductive sometimes to reduce this kind of thing to just carbon accounting, when there are lots of other benefits to this kind of work. But what kind of scale to Scotland has the carbon benefit been of this work? Or what do you expect it to be going forward? If you were to look at Scotland's plans for climate mitigation, what's the significance of this work?

Roxane: 7:46

I think it's difficult to put a number on what's happened in the Flow Country, but certainly in the UK as a whole degraded peatland emits something like 23 million tonnes of carbon dioxide equivalent per year. And that's enough to shift the whole land use system from an net sink of carbon to a net source of carbon. So certainly the amount of restoration that's taking place is not necessarily leading to big gains of carbon, but it's cutting down those emissions massively. It's very difficult, as I say, to put numbers, but you know, the Flow Country is an area where that kind of work has taken place over quite large scale and it is continuing to take place over a very large scale. So certainly, I would say not restoring the peatland is is going to make us fail to meet those targets, but continuing to restore the peatland and then the way that has been happening in the Flow Country for the last two or three decades is certainly going to help us meet those targets in the future. And we know that those gains don't come as I say by the net increase of storage but by the reduction in emission from degraded peatlands, at least to begin with.

Bertie Harrison-Broninski: 8:50

You mentioned a second ago about how the afforestation in the 1970s and '80s was quite destructive. I think a lot of people might expect that planting trees would always be a good thing. But reading your work, it really comes through what a fine science kind of looking after peatlands can be. Could you explain a little bit about why that afforestation work didn't help and maybe go into a little bit more about how carbon dioxide is stored exactly?

Roxane: 9:18

I think one of the important things is to put things in perspective before I do that. So of course, when people did the afforestation when the policies were put in place, it wasn't a deliberate attempt to degrade peatlands. It was an attempt to reinvigorate economy, get jobs in rural areas, and so the intention was genuine. But the policy was perhaps not fully thought through. And certainly the scheme that was put in place had a few issues with it, including the fact that forestry from non native conifer could be planted on areas of deep peat. And what happens in this case is really that the forestry doesn't happen as a standalone operation. It needs drainage. And as I mentioned before, that drainage of peatlands is really one of the things that triggers the emissions, it reduces the capacity of the peat to remain stored and increases the respiration and release of carbon. That can happen through the atmosphere, but it can also increase the export of carbon into the waterways. So export of organic matter, bits of peat that flowed out into the rivers and into the streams. So these losses tend to happen really early in the plantation stages. And then of course, as the trees grow, they themselves can take up carbon dioxide through photosynthesis and build the biomass. And the research that we've done up here in the Flow Country has shown that, on average, most of those plantations lead to net losses of carbon over their lifetime. And that's because those early losses of carbon from the peat are not compensated by the tree growth. And one of the reasons why they're not compensated by the tree growth is that those non native conifers do not grow very well on wet soil that is very nutrient poor. So they would need an awful lot of input of nutrient, extra fertilisation and continued drainage to be able to produce timber and the quality of the timber is not great, either. So what tends to happen in those forestry plantations is that at the end of the rotation, when the trees are taken off, the timber is not really the good quality timber that you'd expect to be able to build, you know, construction material with, often the feed of that timber is to go and become biofuel, or very short lived kind of products like fence posts and things like that. As well as the losses from the peat, there's also a length of time that the carbon is stored in the system that we need to think about. And in this case, the peat stays in the system for thousands of years, and the carbon has been sequestered by those trees, if we're lucky, is going to be at most, you know, a hundred years. So that the difference is not just in terms of the carbon stocks, but it's also in the length of time that this carbon is stored in the system and not kind of sent back into the atmosphere. But of course, and that's really the reason and the main driver for the restoration, at least up here in the Flow Country, the main driver for restoration was not carbon, it was biodiversity. And that was because the forestry also had quite a significant impact on areas adjacent to the forestry on open bits of blanket bog, where waders were declining. So breeding waders, like golden plover in Dunblane, were declining, even, you know, up to nearly a kilometer away from the forestry, that's because they were avoiding the forestry. And the impact on biodiversity was really, really the driver to begin with. Nowadays, we've understood that as well as the impacts of the forestry on biodiversity, there's been a whole series of work in part done by my research group, but by other research groups as well, showing that there's a lot of legacy of that forestry in the system. And there's a lot of impact on water quality, on biodiversity, and then on carbon as well that all together makes forestry on peat, not a really good idea. And what we're really advocating for is, we don't think that trees are bad, and peat is good. We think that what we need is we need to think through policies so that we get the right trees in the right places, and the peatlands remain protected where they're still in good condition.

Bertie Harrison-Broninski: 13:17

And I know you said the policy, the'70s policy was written with good intentions. But I also read in one of your papers that it was kind of abused for tax relief purposes by people like Cliff Richard and Terry Wogan and all sorts. So I guess that feeds into that, doesn't it about how do we make sure that policies are well thought enough through that they're not just quickly abused for kind of financial incentives like that, especially with kind of offsetting markets and stuff like this?

Roxane: 13:42

It's really relevant to think about it even today, because you know, what tends to happen is exactly that, you know, that there's maybe a good intention and a scheme that is put in place for a good reason. But if it's not thought through properly, then it could lead to unintended consequences that are negative, not just for the environment, but for people as well. So it might be negative in terms of how it impacts local communities and things like that. I think there is a risk that if we don't control this a little bit better, and we don't really understand what is happening, for example, currently with carbon markets, and the race to try to offset everything, you know, we might end up making those rash decisions that we may come to regret in the future again. So I think it's just important to maybe stop, pause and think through the consequences, and particularly the unintended consequences of anything that can be implemented through policy, you know, before it's too late, and we have to learn from our errors. But history tends to show that we don't do that very well, and that we tend to repeat the same errors over and over again, especially when there's short term economic gains to be had.

Bertie Harrison-Broninski: 14:47

And so I want to ask you now about permanence. You talked a minute ago about how in perfect conditions, wetlands, peatlands will store carbon for thousands of years, but I also know that wildfires an increasing risk, and you've done some work on this. Could you talk a bit about the risk from fires for peatlands? How you can prevent that or increase resilience of peatlands?

Roxane: 15:09

Yeah, I think what's really cool about peatland in is how amazing they are at having those inbuilt self regulated mechanisms that provide the resilience. And in terms of wildfires, some of the research that we've done has basically shown that in years before the wildfire in particular, one of the big wildfires that we had up here where we did quite a bit of research, what we found was that all the areas that were in near natural condition, they have that inbuilt mechanism, where the peat in a drought year or in dry condition will just shrink, it will collapse. And that's just a mechanical response to the dewatering. The water goes away, the peat structure collapses. And that leads to, perhaps counterintuitively, to increased moisture in the upper levels of the natural peatland. So if there was the conditions for a fire to ignite, it would only lead to quite low level damage, maybe a bit of heat damage, but not burning because the peat at the surface would be too moist to catch fire. The opposite if you go into degraded peatland, what happens in degraded peatlands is that especially when you lose some of the key species that lead to that kind of mechanism of resiliance, like the mosses, what you end up with is a peat that is much stiffer, so it doesn't collapse when it's dry. Instead, it just breaks into cracks. And those cracks are exactly where a fire can take hold into the peat and start smoldering. So basically what our research is showing and, and seems to be kind of the case around the peatlands in the world when we work on kind of synthesising what we find in terms of the more global context is that peatlands near natural condition have those really strong inbuilt mechanisms. It means that even if you have a wildfire, it will eventually return to a carbon sink because the smaller losses at the at the moment of burning and the post fire dynamic will make the system resilient and able to kick back and get this carbon accumulation and storage kind of maintained in the long run. That is not true for a degraded peatland. Instead, it's the opposite, degraded peatlands have bigger losses, more risks of smoldering, and those post fire dynamics lead to systems that are becoming increasingly more likely to burn in the future. So changes in vegetation, drier peat, etc. So in some ways, what we're finding is that as well as the benefits in terms of carbon emission reduction, peatland restoration might have a role to play in terms of future resilience to wildfire by making, you know enabling those resilience mechanism to come back over time so that in a future where wildfires are more likely to happen more regularly, the peatlands have at least the best possible tools in their system to stop the bigger damage and the catastrophic kind of losses to happen. But you know, this is a long game. So you know, restoring peatlands, and restoring the resilience mechanism will not happen overnight, it'll take a long time to build up maybe decades to build up. So if we wait too long to do that, it might actually be too late because the wildfire regimes might have changed by then.

Bertie Harrison-Broninski: 18:19

I wanted to ask you about I think this is more of an English problem than Scottish one, probably but I remember reading in kind of October, November last year, just before COP, there are about 100 human induced peatland fires in England a month because of grouse shooting. I wondered how prevalent a problem this is and whether there's any sign of this being banned. Or well, I don't know if it's something that you know about so much, but...

Roxane: 18:42

there are changes in the legislation that have been put in place and you know, burning in peatland is currently not allowed in Scotland in areas of deep peat. But for you know what happens in the UK and it's very similar in other parts of Europe as well is that you know, there's the things that we can manage in terms of the landscape resilience, but then there's you know, the fires only happen if there's ignition. You need ignition to get the fire started. And almost all you know, of the fires in the UK, and many of the fires in Europe are ignited by people. They're not ignited by lightning strike. And it's not just you know, escaped fire from, you know, mirror burns or anything like that. It's also barbecues in the wrong place, on a nice summer day or a spring day. And I think that one of the important things that we can do as a society is change our behaviour and realise that we are living in a climate where wildfire risks are more likely. What we can't control is what the climate does at the moment. We are at risk. We can't control in the short term what the climate is doing. We can't control that there's changes in the wind patterns bringing more regularly northeasterly dry winds, especially in the kind of February March April period that dry out the litter and make the risk of if there's an ignition, that's triggering wildfire happening, we can't control that. But we totally can control where we have a barbecue and do it responsibly so that at least we can reduce that risk and manage that risk much, much better. That comes with education. And it comes with understanding that wildfire risk, in particular in the UK don't necessarily go with just hot days, they also go with very dry days, and understanding this and educating people about the risk is really important, so that at least if we can reduce the number of times there is an ignition, and then on the other hand, do the management, improve our management so that if there is an ignition, we reduce the risk of catastrophic wildfires, you know, taking hold and burning really large areas, I think we're going to be in a much better place. But to do that, we need to accept that we are now living in a climate where the risks of wildfires are likely to continue to increase and the number of days where there's extreme wildfire weather are going to be more frequent. So we need to adapt our behaviours and our landscape to cope with it.

Bertie Harrison-Broninski: 21:02

And then I want to ask you about the work you've been doing on monitoring. So I know that you've been part of a group developing this new kind of satellite radar form of monitoring peatlands, maybe could tell us a bit about that.

Roxane: 21:13

We started about seven years ago now to work on...we had a workshop where a lot of people came together discussing, you know, the potential for different forms of remote sensing to be used for for monitoring peatland. And in particular, what we were interested in is the use of satellite radar. And one of the reasons we're interested in satellite radar is that unlike optical satellite, satellite radar just goes through clouds. So in a place like the UK, where cloud cover is very common, having something that sees through the clouds is really handy. So what we try to work with we working in particular with a company that's called Terramotion. And what they did is they developed an application of interferometric satellite radar. And that particular type of satellite radar has been used for a very long time to monitor subsidence in particular in kind of urban areas or mines and things like that to look at land subsidence. And what they did is they developed a way of processing the data from the satellite that gave complete coverage over landscapes. So not just built areas, but also any area. So the whole of the UK, for example. And what we decided to do with that is to see what could we understand from peatland if we started to look at the signal. So what the satellite does is every six days, it goes around the planet, it sends back the data, the data is then processed by Terramotion and produces a time series of the relative position of the surface. And that effectively, it gives us a time series of the bog going up or down. Now in peatlands, we knew and we've known for a very long time that peatlands have the capacity to go up and down as a mechanism of resilience that depends on how much water, gas and organic matter there is. So if you think about a peatland in a time, where there's a lot of water it will swell, and if you think about a peatland in a time where there's less water or high demand for water, it will shrink. And those signals of up and down is also known as bog breathing. And what we found with InSAR is that previously, although we knew about bog breathing, it's incredibly difficult to measure on the ground, because you can imagine trying to walk over a wobbly surface measuring how it wobbles, it's really impossible to do it at scale. But with the satellites, suddenly we were able to see those signals of bog breathing over whole landscapes. And what we did was basically a really extensive comparison of the features on the ground and properties of the peat on the ground and the satellite signal. And what we found was that the signal that bog breathing signal was very diagnostic of the peatland condition. So using satellite radar signals of motion depending on the long term motion, is it going up? Or is it going down? The peak timing, what time does the bigger of swelling happen? The distance between the peaks and the troughs, the amplitude of the swelling. With all these properties, were able to come up with a way of qualifying every pixel and defining how good a condition it was - was it degraded, was it in good condition? Was it more likely to be dominated by sphagnum or was it more likely to be dominated by shrub, for example? And using that, it becomes a really really cool tool that we can use to look at, for example, restoration outcome. So if we have a peatland that is restored that is management intervention, we can use the bog breathing to see when it starts, it tends to have very flat signals and not much bog breathing as dead. And then as it restores, we can see where it goes, what are the trajectories of the different areas that have been restored and we can start to understand better which direction is going is it coming back to a near natural signal in good condition? Or is it not and if it's not then we can maybe target interventions to rewet better or change, you know, introduce vegetation and so on. So it can become a really important tool in terms of the management of the restoration outcomes, or at least the monitoring of the restoration outcomes. And of course, the advantage is that you can do it at scale, so we could potentially do the whole of Scotland, rather than having, which we can do on foot, for example, it's much more cost effective to do it like that. So this is the kind of work that we're developing at the moment. And a lot of the research has been led by my colleague, David Large from the University of Nottingham, and with the company Terramotion, but has been funded by NERC but also by NatureScot, and others as well. So it's something that has been really a big part of our work. And as part of this, you know, I've got funding from the Leverhulme Trust, in particular, to really understand that behaviour, and the response, in particular with extreme events. So we know how condition works. Now, we are also looking at that resilience, the idea of, well, if there's a drought, what happens to bog breathing? If there's a wildfire, what happens to bog breathing? If there's multiple droughts, what happens to bog breathing? And these are the kinds of things that we're working on at the moment.

Bertie Harrison-Broninski: 26:10

So if we could be looking at a near future where a government can be tracking the restoration of their peatlands in semi near real time, could that significantly change kind of the extent to which governments are addressing this issue? I mean, it sometimes feels like peatlands don't get due consideration in climate mitigation planning, at a kind of governmental level. Do you see any sign of that changing going forward?

Roxane: 26:34

Yeah, I mean, we have received quite a lot of support from NatureScot and government agencies towards this work. So I think that at least there is a realisation that this could be a really important part of how the future can work. But I think you know, that and other technologies that are being developed together could be really, really powerful tools, not only to make strategic decisions to decide where is the best place to do the restoration, because these areas are the most degraded and are more likely to lead to higher carbon gains in the in the near future. But also, in terms of that kind of investment. I think that there's been, you know, a huge amount of money invested in restoration by the Scottish Government with, you know, £250 million at the moment pledged for the next ten years, they will need to be accountable for that investment in some way or other. And I think that the remote sensing tools that the team here and others are developing at the moment are going to have to be part of that way of demonstrating that the investment was worth, it's not only in terms of potential emission reduction, but also in terms of all the other benefits. So you need to have a way of measuring these outcomes. And I think that this is going to be part of the solution for measuring those outcomes and being accountable for the investment that has taken place so far, and that is going to continue to take place. So I think there's definitely a place for these kind of remote sensing tools in the future in terms of not only informing restoration choices where to do restoration, but certainly in terms of monitoring and being accountable for those investments.

Bertie Harrison-Broninski: 27:59

How do you see peatland restoration in relation to the fervour for carbon dioxide removal technologies like CCS, BECCS, direct air capture? Could peat have a bigger role than it's being given currently in integrated assessment models?

Roxane: 28:17

My perspective is that, first of all, it's not just about restoration, it's also about protection. So I think it's absolutely imperative that we protect the areas of peatland that are still in good condition and we stop drainage and we stop anything that degrades peatlands. Because yes, we can reinstate carbon sequestration in short amount of time, but the carbon that is lost is irrecoverable. We will not recover the carbon that has been lost by degraded peatlands in our lifetime and probably not in our children's lifetime. This is really long term thinking here. So I think we absolutely must restore peatland, we absolutely must protect our peatlands. But I think that even if tomorrow we decided to invest in restoring all the peatlands in the world, it would still not fix the problem. The problem is that we're using too much, we're producing too much carbon dioxide, we need to cut fuel, we need to cut our dependency on oil and gas. And we need to do that much quicker. I think than what the transition are saying. And perhaps, I'm not certain because I'm not an expert at all in carbon removal technology, but perhaps they will have a role to play. But I think we should focus really on the things that we know do work like peatland restoration and afforestation in the right places. And I think that we must do that not just because of the carbon because they also provide so many added benefits in particular in terms of biodiversity and water quality and they can be compatible with you know, appropriate use of land for production of food and things like that. So I think it's really important to get the balance right and to invest into nature based solution for the right reasons in the right places. We must protect what remains of our natural ecosystem because you know the peatlands, just like the rainforest, just like the tropical areas, the mangroves, we won't be able to replace them if we lose them. Not in our lifetime. And the losses in terms of biodiversity and carbon that will be incurred by continuing deforestation and continuing peatland degradation are just not going to be compensated. So I think and I know from some of the work that I've been doing that we're not going to be able to meet those targets until we take radical action to change our behaviours as a society. And that will come with very difficult choices and difficult trade offs. Some of these are going to have to be reducing our emissions first and foremost, before we try to compensate all those or offset all those emissions.

Bertie Harrison-Broninski: 30:41

My thanks to Roxane for coming on the show. If you enjoyed this episode, please do check out more podcasts and articles including more on peatlands at www.elc-insight.org. I'll also put some further reading in the episode description below. Please subscribe or follow us on your favourite podcast platform, and we'll be back soon with more exciting interviews with climate experts. Thanks for listening!