Photo illustration by Kelvin Li
Trees have an incredible ability to absorb carbon — which means protecting, planting and restoring forests are a (relatively) easy way to address global warming. Climate change, however, is making it more complicated. Our forests are literally going up in smoke, which has far worse consequences than one might expect. In this episode, we explore the role forests play in carbon sequestration, how increasingly intense fires are threatening to turn them into a carbon bomb, and how technology (think drones, satellites and lasers) can assist in our replanting and conservation efforts. The forests have helped us, it’s time to help them.
Featured in this episode:
Subscribe to Solve for X: Innovations to Save the Planet here. And below find a transcript to the first episode “We need to save the trees — but how?”
Intro: a series of clips highlighting national replanting efforts
Manjula Selvarajah: This is Solve for X – Innovations to save the planet. A series where we explore the latest ideas in tech and science that could help us tackle climate change.
I’m Manjula Selvarajah, I’m a tech journalist. It means I spend a lot of time scouring the internet, checking Twitter, bugging people to get back to me before my deadlines. As for my natural habitat, well… you’ll normally find me here; in front of my computer, in my home studio, sitting behind a microphone, but today we’re heading into the forest — metaphorically.
Manjula Selvarajah: Okay, so we all know that trees are good for the planet, but hear me out. When I look at a tree — yes, I see the shade it provides from its leaves, I feel that it’s noticeably cooler when I stand in the shade, but thinking about carbon storage and what it’ll take to plant enough trees to have an impact on the climate? Well, that’s not so obvious. And if I try to imagine just how much carbon is sequestered in any given tree, I’m lost. I reached out to a researcher whose job it is to measure how much carbon is stored in trees, but on a global scale.
Manjula Selvarajah: Lola and her colleagues at NASA are working on a special project to help us better understand this planet. Tell us — how do you use satellites and radar and how do you do the work that you do using technology?
Dr. Lola Fatoyinbo: What I work on in particular is mapping. Essentially differentiating the different types of forests and ecosystems that we might have, because it turns out that we don’t have really good maps for every type of forest or ecosystem all over the world. And that’s kind of one of the most basic things that we need — especially if we’re trying to manage it or conserve or reforest. We really need to know: what do we actually have right now on the ground?
Manjula Selvarajah: If the goal is to keep carbon emissions in check, it’s really important to have a sense of how much (exactly) is stored in biomass like trees, leaves, and soil.
Dr. Lola Fatoyinbo: As we are changing the distribution of the forests, this has really, really high implications. And in fact deforestation is one of the largest emitters of carbon dioxide into the atmosphere because as we cut those trees, that carbon goes somewhere. And then those trees that we’ve cut, not only does it go up, but we also stop taking up more.
Manjula Selvarajah: So it’s a double hit.
Dr. Lola Fatoyinbo: Absolutely.
Manjula Selvarajah: To calculate how much carbon is stored in a tree, you can painstakingly measure the height, diameter, and weight of the tree and model it — or a much easier way is to use LiDAR, which stands for Light Detection and Ranging.
Dr. Lola Fatoyinbo: Instead of going into the forest and measuring every single tree like we usually do (we measure the diameter and the height of every tree) — we bring this instrument, it shoots lasers essentially at every single tree and based on that, we get a full 3D scan of the forest.
Manjula Selvarajah: My sense is that it goes beyond a map because it actually speaks to the quality of the forest. Is that right?
Dr. Lola Fatoyinbo: Yes. You might be looking at something from the top in 2D and it looks really dense and it looks really tall, but you can’t tell the difference between a relatively short forest and a relatively tall forest — but it makes a huge difference when it comes to the amount of carbon that is stored in these forests.
Manjula Selvarajah: It’s funny because I was imagining you kind of walking through a forest going 60, 50, 20… for some reason!
Dr. Lola Fatoyinbo: I do that for height. I do that for the height aspect of it. I go through and I try to figure out if I can see the top — which it’s really hard often — if you actually try to figure out how tall a tree is, it’s actually a really hard thing to do from the ground because you don’t actually see the top of the tree from the ground, you have to be pretty far away.
Manjula Selvarajah: When Lola says pretty far away, she might be understating it. She also works with similar instruments on airplanes, as well as way up on the International Space Station — they call the mission: GEDI. It stands for Global Ecosystem Dynamics Investigation. How do programs like GEDI help us decide where to plant — and more importantly — what areas we should protect?
Dr. Lola Fatoyinbo: One of the main benefits is that it allows us to explain where trees are right now and where forests are right now. And so that already gives us the most important information: what type of forest can grow here. And based on what can grow there and what’s already growing there — that’s the type of forest that most likely should be growing there. And the same thing would go with protected areas; if you’re looking for a certain type of forest to protect, you could use GEDI data to say: I’m looking for high carbon, primary, tropical forests. You can use the data, and the products, and the maps that come out of our missions to help inform your decision.
Manjula Selvarajah: This kind of detailed data about the Earth’s forest is vital for policy — and because NASA’s data is free and open to the public — it’s also a game changer for monitoring all kinds of climate commitments and offset projects. Right now it’s up to every country to report how much carbon is stored in their forests. The maps Lola works on offer a way to fact check that information. To find out what’s happening on the ground with Canada’s forests, I reached out to Faisal Moola, an ecology professor at the University of Guelph.
Faisal Moola: We now know as scientists that trees are really, really critical if we are going to survive the catastrophic, dangerous impacts of climate change because in some ways they act as a hedge or as a break — as a hand brake — against runaway climate change; because as we continue to emit, trees are removing carbon dioxide and storing it, locking it away. So they’re very, very important in the fight against climate change.
Manjula Selvarajah: Now the People, Plants and Policy Lab — can you tell me what that is (very briefly) and what you’re trying to achieve there?
Faisal Moola: Our lab weaves together Indigenous knowledge and Western science, and then we try to advance the stewardship and the protection of that relationship by advancing new forms of policy that can be enacted.
Manjula Selvarajah: What is the impact that climate change is having on forests in Canada?
Faisal Moola: The impacts of climate change are: actually taking what is a sink for carbon dioxide and turning it to a source of carbon dioxide. The problem is that when trees are affected by — say fire — when they catch fire and they burn, or they’re eaten by insects or they’re degraded and decomposed by fungi or bacteria — much of that carbon dioxide that was stored within those trees gets released back into the atmosphere. And this is the real sort of catastrophic nightmare solution that some scientists have described as the “carbon bomb.” The idea that so much of the carbon that’s locked up within our trees and our forest might actually end up getting released back into the atmosphere, thereby driving the impacts and the scale of climate change much, much worse. So in other words, making a bad problem much, much worse, as a consequence of climate change.
Manjula Selvarajah: Gosh, that was a revelation that I wasn’t aware of — that the danger we face is the reversing of that sink effect. Canada has some really important sinks. Would that be right?
Faisal Moola: Right. Our emissions may in fact be a lot, lot worse than we actually account for, and we manage for; and that’s really, really frightening. Politicians would often say: the emissions that are happening from heavy industry in Canada and are happening from personal vehicles and commercial vehicles — those emissions (to some extent) are being offset by the fact that Canada is blessed with as great green cloak of woodland — all the way from Newfoundland as far west as the Yukon. The fact of the matter is, that the latest science is actually showing in the last few years, our forests have actually been a source, not a sink.
Manjula Selvarajah: To complicate things, wildfires aren’t usually included in the tally of carbon emissions a country produces. The thinking has been that the fires are naturally occurring, so the emissions remain off the books. Even so, experts are paying attention and researchers are looking into why forest fires are becoming more intense and what we can do about it.
Amy Cardinal Christianson: I’m Amy Cardinal Christianson. I’m a Métis woman from Treaty 8 Territory and I’m a fire research scientist for the Canadian Forest Service, where I work mostly on Indigenous fire stewardship.
Manjula Selvarajah: Amy is an expert in fire ecology. That means she studies how fires behave and what factors can lead to more extreme events.
Amy Cardinal Christianson: 2021 was really an outstanding fire year in Canada; we saw 217 evacuations. And in previous years, our highest was 103 evacuations; so it was more than double. Now, what we’re seeing with these massive fire events is that they’re burning so hot and so intensely that they’re really just kind of obliterating everything in their path and actually almost turning certain areas into deserts.
Manjula Selvarajah: In addition to her research, Amy also hosts a podcast called “Good Fire” that looks at the role fire plays for Indigenous communities around the world. And over the past few years, she’s finding that more and more people are interested in how traditional fire stewardship might be able to help.
Amy Cardinal Christianson: I think when people are really experiencing fire like that — where it’s impacting their daily life — people hundreds of kilometres away were experiencing smoke and nobody wants to live their summer in smoke. So I think that people really start thinking: what are we doing? How is this going so bad? What are other solutions out there? And I think that’s where Indigenous people have really been stepping up in Canada and saying: here’s how we used to do it — and the science shows that we had smaller fire events, and that we had healthier ecosystems, and better biodiversity in Canada. I think because of that fear from climate change, people really are starting to say: maybe we should put some attention into this.
Manjula Selvarajah: As unexpected as it sounds, fire is one of the most important tools or technologies we have, to deal with the increasing risk of wildfires. In Australia, cultural burns are used to manage for wildfires and have even been linked to carbon offset programs to help reduce emissions. I wanted to get a sense of what fire stewardship can look like.
Amy Cardinal Christianson: We call it “good fire” because it’s fire that enhances our territory. It’s really in contrast to the bad fires that we see on the news all the time — that’s not the type of fire that Indigenous people want on the landscape. We want that “good fire” that actually prevents those type of events. When you do a “good fire” on the landscape, what you’re really doing is cleaning up. That’s what lots of elders talk about — it’s almost like pruning — but using fire instead of using shears. You’re trying to get rid of all the dead limbs and other things, but really not disturb the roots of the plants. That’s why it’s so important about the time when you burn, because you really want a low intensity fire moving through that area.
Manjula Selvarajah: This is quite different from how Canada has historically managed forests… for timber. Amy said that when settlers first came to Canada, they brought with them European styles of forest management.
Amy Cardinal Christianson: One of those things (that came with that) was this idea of a monoculture — but what tends to happen is that’s in opposition to an Indigenous view of the forest, which is to manage for biodiversity. Instead of managing for biodiversity, you’re managing for this one type of tree. That’s what we’re really seeing. I tell people: when you go to the mountains and you look over the viewpoints and you see that carpet of green forest — and lots of times people think that’s beautiful — but that’s really not a natural forest. What that is, is a fire suppressed forest.
Because we have these monoculture forests, when a fire starts in a forest, it basically has no point where the fire behaviour will decrease; where it would hit a meadow. Once the fires get rolling through these monoculture forests where everything’s the same, all the trees are the same age, the fires really start to burn really hot, really intensely.
Manjula Selvarajah: This lack of biodiversity has ripple effects. These monoculture types of forests, these plantations of trees, not only are they more susceptible to pests or disease, they’re also prone to larger fires.
Amy Cardinal Christianson: What some of my colleagues, who do research in the boreal forest, are seeing is that the fires are burning so hot and intensely that not only are they consuming the trees (that take in carbon and store carbon) but also the soil. They’re burning through layers and layers of soil and through peat; and it really is impacting the forests ability to regenerate after a fire.
Manjula Selvarajah: Burning through layers of soil means that even more carbon is released than ever before, which is bad for climate change. And the weather changes brought on by our warming climate? They’re only making things worse.
Amy Cardinal Christianson: Some of my colleagues have work showing there’s more lightning strikes associated with climate change, which leads to more forest fires. But then there’s also, because of more human activity, there’s more human caused fires. It’s a huge cumulation of multiple factors that are really impacting the wildfire situation in Canada. Like they say, it’s a complex problem, and there’s not an easy solution unfortunately.
Amy Cardinal Christianson: One thing we’re not often thinking about is the wildfire risk that might result from having two billion new trees on the Canadian landscape. For fire researchers, that’s probably the first thing that we think about; what types of trees are being planted, where are they being planted? For me, that’s really where these replanting of trees can actually work to reduce fire risk to communities if they’re done in the right way. If the right type of trees are planted in the right areas, it can actually make healthier forests that are more resilient to wildfire.
Manjula Selvarajah: Okay — so to help maintain forests as carbon sinks, there’s what we can learn from Amy about Indigenous fire stewardship. Then there’s Lola, mapping biomass at NASA with satellites and LiDAR. But there’s also another remote sensing technology… drones! I spoke with ecology Faisal Moola to learn how drones can help with conservation efforts.
Faisal Moola: Some of the really interesting things that I’m involved in is, I’m using drones with colleagues from the U.S. Forest Service. We are beginning to do biodiversity inventories: so lichens. When I was a student we used to call them a “step over species” because you would “step over” the lichen to get to where you really wanted to go. And nobody ever looked down at (oftentimes) these beautiful, beautiful lichens. So they’re using drones to essentially detect the lichens on rocks and then to identify them down to the species level. And we think that we’re going to start discovering new species to science using drones, because we can survey vast areas of (often very) inhospitable habitat.
Manjula Selvarajah: Faisal explained how drones open up even the hardest to reach places to science. But there’s another potential that companies around the world are starting to explore. In the U.S., the Forest Service is using drones to help restore burn sites in California and Oregon. And in Canada, there’s the venture Flash Forest, a drone company that replanted trees in B.C. and Kenora, Ont. — two regions which suffered massive fires last summer. I asked Faisal what he thought about this idea of drone planting.
Faisal Moola: Canadian forests, especially the Northern boreal forest, are very well adapted to dealing with fire. The trees have what’s called serotiny, which means that they can survive fire; the cones on the trees open up after a fire and they release their seeds. But if every single tree has been killed and burned in the fire, there’s no native source of cones. And any seed that was buried in the soil oftentimes is no longer viable because the temperature at which the fire happened was so high, that it killed the seed. In these areas, if there’s no native sort of seed — the only way you can reforest that place is by using the drone technology because you’re bringing in new sources of seed from outside of that native forest.
Manjula Selvarajah: What are some of the issues that need to be addressed in terms of drone planting?
Faisal Moola: Right — we need maps of Canada. We have a very coarse understanding of the different types of habitats that exist in Canada. We have the smartest people in the world that know how to do this. They’re using remote sensing technology, satellites, LiDAR, aerial based cameras… all sorts of things. There’s a lot to be figured out by the technology side. But I do want to emphasize the role of Indigenous people because as with a lot of tech, we tend not to think about the social consequences of the technology. While our primary objective might be the mitigation of climate change by planting new forests; let’s not just think about planting forests with just trees.What if we used the drone technology to deliver some of these important biocultural plants that Indigenous peoples need. The payload of the drones could include the seed of blueberry or raspberry or other types of plants that have real cultural significance as well. What I’m really hoping that technology companies are going to do is start partnering with Indigenous peoples.
Manjula Selvarajah: So what you’re then doing is designing and building a real forest as opposed to a plantation.
Faisal Moola: Exactly — but at the same time I’m very fearful that we simply use the technology, but don’t change the model of management. The large multinational logging companies, Canadian companies, Malaysian companies, Indonesian companies, Brazilian companies; they’re also looking at drone technology because they’ve realized that they can use drone technology to reestablish plantations much cheaper, much more efficiently and probably at scale. The danger is that this just furthers the same industrial model of forestry that has done so much harm to the planet and Indigenous peoples that depend on these forests.
So we all have to remember that there’s been a lot of technology in forest silviculture. The invention of pesticides was a technology. The idea of growing seedlings in greenhouses and planting them in the forest was a technology. We’ve had a lot of technology, but the model never changed. So technology is not going to save the forest or save the planet; it’s how we manage the forest that is going to impact whether we are doing this sustainably or not.
Manjula Selvarajah: Like Faisal said, it comes down to how we manage the forest; an Indigenous partnership is key. Experts agree, drone technology holds a lot of potential for replanting — especially in hard to reach areas in unsafe terrain. And after devastating events, it’d be useful to repopulate areas with native seed. Drones could deliver payloads of seeds much more efficiently over very large areas, but it’s still such a new field.
Reporting shows there’s a need for transparency around how effective drone planting actually is; and speaking of reforestation, there’s a need for more research. This is something Stephen Elliott has been looking into. He’s an associate professor of biology at the Chiang Mai University in Northern Thailand.
Stephen Elliott: Basically I am past retirement age, I still get a salary from the university and I get paid to play with toy airplanes; it’s brilliant.
Manjula Selvarajah: Stephen has been studying reforestation in Thailand since the mid-’90s, long before drone technology. He co-founded the Forest Restoration Research Unity.
Stephen Elliott: We have this National Park right next to the university, it’s called Doi Suthep-Pui National Park. And on that mountain is 680 tree species; the area’s about 260 square kilometers. I come from the U.K., and in the whole of the U.K. (thanks to the ice ages) we have about 25, truly native forest tree species. So there’s plenty on that mountain to keep a botanist happy, over many lifetimes I would say.
Manjula Selvarajah: Stephen regularly uses drones for surveying and gaining a different view of the forest.
Stephen Elliott: You have no idea what a restrictive view you get of the forest from the ground. You’re peering up at the trees with binoculars, you’re in the shade, it’s raining, your binoculars are getting wet; you can’t tell whether the trees got ripe fruits or they’re not ripe yet — ready for the seed collection. Difficult. Difficult. But with a drone you can fly over the forest, you can pick out all the trees with fruits, you can pick out all the trees with flowers; you of course hover the drone over the tree, write down the GPS coordinates — grab a handheld GPS or a phone and off you can go and you can find a seed tree in a few minutes.
Manjula Selvarajah: And while a lot of attention has been paid to improving the technology of drones, he’d like to see more innovation in another area.
Stephen Elliott: Up until now everybody’s been focusing on: how big should the drone be and what about the battery life; that’s the engineering of drones. I think drone engineering is evolving and progressing at lightning speed. Quite honestly I don’t think we need to do more research into how to build better drones. The engineers are already doing that. We are in a biology department; we should be concentrating on trying to figure out how to get the seeds to actually germinate after they’ve been dropped.
Manjula Selvarajah: And that’s exactly what Stephen and his team are concentrating on. They’re testing what ingredients might help the seed to germinate, but getting a seed to sprout is only half the problem. There’s another consideration, like how to keep them safe from seed predators. In Canada that could be birds, chipmunks, or insects. In Thailand … they need to think about the rats.
Stephen Elliott: If you don’t stop the rats from eating your seeds; the rats are sitting there waiting for the drone to come over and it’s like a buffet lunch descending from heaven. Down comes breakfast, dinner, lunch and tea all for the next three weeks; the rats go out and they can eat the whole lot.
To be fair, we shouldn’t expect too much from dropping seeds from drones because in nature, the seed rain that comes into a reforestation site from outside; 99.9 percent of those seeds are going to die. So to do better than nature, if you are getting just 1 percent of the seeds surviving and growing — you are already probably doing a little bit better than the mortality rate that naturally occurs through seeds coming in.
Manjula Selvarajah: Even as we increase the success rate of seeds, we still have to remember it takes years for a tree to grow to a size capable of storing that much carbon. How then do you design a forest to sequester the maximum?
Stephen Elliott: So natural forest — with the biomass of a natural forest, the structure of a natural forest, the biodiversity of a natural forest and the ecological functioning of a natural forest — that is by far the best way to suck up carbon. The natural forests are the product of millions and millions of years of this competition sorting everything out, which species should grow in which place, which minimizes its competition with its neighbor.
That’s evolution, you don’t need to be a rocket scientist to figure that out. The moment you replace it with almost anything else that hasn’t been practising how to do it for 400 million years, it’s not as efficient. What we should be trying to do is to kind of recreate the original forest as closely as possible. So, trying to recreate the look and feel of the original forest is by far the best way to suck up carbon, the best way to preserve a watershed and the best way to get your biodiversity coming back.
Manjula Selvarajah: Like Stephen said, if we’re truly going to be able to tackle climate warming by replanting; that means confronting the issue of biodiversity and thinking about what actually makes up a forest.
Faisal Moola: This is why I think that these social ecology questions are really important. We need to think about governance, we need to think about land use planning, we need to think about a vision for our forest that goes well beyond the current government’s obsession with planting two billion trees by 2030. And, think about what will this country look like in 50 years or a hundred years time. The people that live there right now, the Indigenous peoples have to be leading that conversation.
Manjula Selvarajah: With that in mind — back to fire researcher, Amy Christianson.
Amy Cardinal Christianson: I think that Indigenous cultural burning and Indigenous fire stewardship offers people a sense of hope; that there are ways that we can manage and that we can adapt to climate change. And I think that Indigenous peoples in Canada have adapted to probably one of the most significant events ever, which was colonization. So climate change is just another thing that our Nations will have to adapt to.
Manjula Selvarajah: Solve for X is brought to you by MaRS. The episode was produced by Ellen Payne Smith. Gab Harpelle is our mix engineer, Lara Torvi and Heather O’Brien are the associate producers. Mack Swain composed our theme song and all the music in this episode. Kathryn Hayward is the executive producer. This episode includes clips about large-scale tree planting campaigns from Global News, MrBeast and Al Jazeera. I’m your host Manjula Selvarajah. Watch your feed for new episodes coming soon.
The Mission from MaRS initiative was created to help scale carbon reducing innovations by working to remove the barriers to adopting new technology. Mission from MaRS thanks its founding partners, HSBC, Trottier Family Foundation, RBC Tech for Nature and Thistledown Foundation. It has also received generous support from Peter Gilligan Foundation, BDC, EDC and Mitsubishi Corporation Americas.