You are here: Episode 1: Carbon Sinks and Strategies

Carbon Sinks and Strategies

Could a giant vacuum that sucks dangerous greenhouse gases out of the atmosphere really be effective in reversing climate change, or is this just a thing of science fiction?

Humans release 40 billion tons of carbon dioxide into the atmosphere every year, and that number will continue to grow unless the global community makes serious efforts to reduce carbon emissions. We’ve long known that forests are “carbon sinks” that remove carbon from the atmosphere for photosynthesis, but man-made technology that can artificially trap and store carbon could be essential to mitigating the effects of climate change in the future.

In this episode of Big World, Nicholson explains carbon removal and why scientists are looking to this emerging technology as a potential solution to the world’s carbon woes (2:24). He discusses whether scientists (4:43) or environmentalists (5:57) have come to any consensus on the need or feasibility of technology-based carbon removal strategies, and if technological advances got earth into the climate change mess to begin with (8:45). Grounding the carbon removal conversation, Nicholson hypothesizes about what a carbon vacuum in Bangkok might look like and why any effort to mitigate climate change has global, not just local, effects (16:37).

What would Nicholson do to reduce carbon in earth’s atmosphere? Hear his top five policy suggestions for mitigating climate change in our segment “Take Five” (12:15).

0:07   Kay Summers: From the School of International Service at American University in Washington, this is Big World, where we talk about something in the world that truly matters. Today we're talking about carbon removal. I'm Kay Summers, and I'm joined by Simon Nicholson. Simon is assistant professor and director of the Global Environmental Politics Program in the School of International Service. He is also director of the Institute for Carbon Removal Law and Policy and here at American University. Simon, thanks for joining Big World.

0:36   Simon Nicholson: Of course, Kay, thank you.

0:37   KS: I want to start our conversation by just stipulating a couple of facts up front. So these are "true or false" questions. First, the climate is changing and humans are to blame. True or false?

0:48   SN: That's true.

0:48   KS: Okay. Second. Carbon dioxide, or carbon emissions, is the culprit, true or false?

0:48   SN: True, with some nuance, which we can add, but yes, true.

0:58   KS: Okay, great. So, to simply state the problem, it's kind of a carbon problem. As I understand it, there are two parts to this. There's the emissions part where we talk about how to reduce the amount of carbon we're releasing, and the removal part, which looks at how to get rid of or sequester existing carbon in the atmosphere.

1:16   KS: So up until now, where has most of the policy and advocacy evolved on the carbon question: emissions or removal?

1:24   SN: Yeah, so the climate change conversation is largely a what's called a mitigation conversation. So if we think about climate change as a problem of human activity, putting carbon dioxide and other so-called greenhouse gases into the atmosphere, then what the international community and everybody else who cares about climate change has been wrestling with is, how do we stop the greenhouse gases from getting there? How do we change energy systems or land use systems so that we are mitigating the problem, keeping carbon from entering the atmosphere in the first place?

1:55   SN: Now we're entering a moment now where an increasing number of scientists and policy makers are looking at the carbon math. They're saying how much carbon are we putting up there? And how much can we reasonably put into the atmosphere before we start to see real problems?

2:11   SN: And they're saying, "Look, we're running out of options. We're not moving quickly enough on that mitigation piece."

2:16   KS: And that brings us to carbon removal.

2:18   SN: Yeah, that brings us into this carbon removal conversation.

2:21   KS: So what exactly is carbon removal?

2:24   SN: So carbon removal is the idea that there might be pathways by which to pull carbon out of the atmosphere and then to hold that carbon in long term storage or put it to some sort of beneficial use.

2:35   KS: Okay. What is the scale that we're talking about? How much carbon would need to be removed from the atmosphere in order to make a real difference?

2:43   SN: So this is an interesting question, Kay. And there are a number of ways to answer it. Let's kind of start with what's in focus at Stanford and have been saying. There's a team out of Stanford that's been suggesting that, just looking at the carbon math and what might be possible by the end of the century, we might be looking at a scale of something like 15 billion tons of carbon dioxide pulled out of the atmosphere per year to make a real difference in terms of climate risk. 15 billion tons of carbon dioxide out of the atmosphere per year.

3:16   KS: And to put that number in context, what does that represent, 15 billion tons of carbon? I don't feel like I have a good sense of that means in terms of activity or ... Is there a way to kind of break that down for people at all?

3:30   SN: No straightforward way, and that's one of the challenges with talking about these sorts of options or these sorts of challenges, right? We're just not used as individuals or as groups of people wrestling with things at this scale. At the moment, all human emissions of carbon dioxide into the atmosphere total about 40 billion tons per year across all countries. And so we're talking about taking a huge chunk of those emissions, and those emissions are said to grow through time, that's part of what we're wrestling with, and finding ways to pull them out of the atmosphere and hold them underground.

4:03   SN: At the moment, we have a couple of demonstration projects, so different types of carbon removal. The largest ones you can point to are on the scale of maybe one or two million tons per year. So the zeros really matter. We don't know if we can do this yet at the sorts of scales which some scientists are suggesting might be necessary.

4:22   KS: So in the face of it, I think it sounds a lot easier than it is. We just remove the carbon. We can put a giant vacuum cleaner out, we suck it all in, we figure out what to do with it. Is there a broad agreement in the scientific community about carbon removal? And on the flip side, are there any common criticisms of the science or economics or feasibility of technology-based carbon removal?

4:43   SN: If there's a consensus in the science community about carbon removal, it's a soft consensus. And the consensus would be something like, we need to examine these technological pathways and workout what's there. There are a number of scientists who say, "We don't need these technologies. In fact we can still stay beneath critical climate thresholds through mitigation alone, and with adaptation measures that is, changing the way that we live in response to climate change, we can clean up what's left over." Some scientists see carbon removal as a distraction from the real work that needs to be done. And it's something we should talk some more about.

5:16   SN: But the growing scientific consensus, if there is one, is we need to work out what's here. Do any of these technologies actually offer promise?

5:24   KS: So, talking about the scientific community, and then talking about the environmental advocacy community, you know, environmentalists always want to believe that they're very science-based, but then everybody has their biases and their prejudices about what they think will work. So it sounds like there's kind of a spectrum here with carbon removal. At one end you have some pretty traditional old-school conservation methods like forestation and urban forestry, trying to plant more trees basically. On the other end, you have more technology-based solutions like capturing and storing carbon in a liquid form.

5:57   KS: So among these more traditional conservationists and the people who've kind of driven this work for all these years and frankly helped fund a lot of it, are these more technology-based ideas controversial and is there broad agreement among environmentalists about the efficacy of carbon removal?

6:15   SN: Maybe we can just start with the categories that you said, because those are very helpful.

6:19   KS: Yeah, okay.

6:19   SN: When we're talking about carbon removal there are lots of different ways potentially to remove large amounts of carbon out of the atmosphere and hold it in storage. As you suggested, at one end you have purely biological pathways, so that is by managing forests, by planting bio-energy crops, by changing how we farm and managing soils. There might be ways to store vastly more carbon in existing kind of biological systems. For the most part, environmental communities, environmentalists embrace those sorts of options for reasons that we can kind of dig into a little bit.

6:58   SN: At the other end of the spectrum are these other technological options that you've talked about. So if on one end of the spectrum you've got purely biological pathways, at the other end we've got much more mechanized or technological pathways, the most obvious of those is what's known as direct air capture. Is using machines or chemical membranes to take carbon dioxide directly out of the air, and then you'd have to turn it into some sort of liquid form and inject it under the ground. Those sorts of more machine-based or technological options are not so well received necessarily by the environmental community.

7:29   SN: And so part of what's going on here is that, the environmental community, and particularly in the United States, but in lots of other places as well, kind of comes out of this kind of conservation understanding that there's something about human activity that is pushing against natural systems. And the best way to protect this thing called the environment is basically to try and limit human intervention, is to try and kind of keep people out of these systems. And so something that looks like a highly technological and large-scale intervention is something that doesn't fit with traditional forms of environmentalism.

8:02   SN: So these become really, really difficult conversations for the environmental community to have in the face of this new carbon math that suggests that these sorts of options may have to be on the table if you're really serious about keeping beneath critical climate thresholds.

8:16   KS: Do you think it has anything to do with the idea that technology in the environmental world, like you said, there's the natural systems piece of kind feeling like it's the enemy, but also the history with oil pipelines, natural gas pipelines, of using kind of underground processes to capture and store things that can be very harmful if the pipeline doesn't hold up. I mean, is that part of this? That there's this idea if you capture a bunch of carbon underground that what's going to happen when there's a problem with that?

8:45   SN: Yeah, I should be really clear then. I'm really kind of on board with many pieces of that environmental critique. If we look at the environmental mess that we find ourselves in and try and trace it back to root causes, there's something about our current dependence as a civilization on particular forms of technology, and on particular understandings of progress and industrialization that are really driving the fact that we now face these environmental challenges. And so by one reading of that, to turn around and say, "I have got the answer for your problem. We're going to use these big technological systems that kind of got us into this mess in the first place. We'll tweak them, and we're really smart, we're going to make this work this time." There's something a little fishy about that perspective. And at the same time, look we're going to use technologies to help us wrestle with the environmental situation moving forward, that's a given, right? And so the technological conversation is not, should we use technology or not, the conversation really has to be, to what ends should technologies be developed and directed?

9:49   SN: So there might be ways to think about things like carbon removal technologies that also take us into preferred human futures, right? Rather than just kind of baking in the current challenges that we have.

10:03   KS: So we've talked a little bit about some ideas for projects. What kind of carbon removal projects and initiatives have been put into practice or tested already? And among those are there some or any that seem particularly viable for the immediate, for the near term?

10:20   SN: Yeah. So if we think just about those biological pathways as an obvious entry point, then afforestation or avoiding deforestation projects are already happening at very large scale.

10:31   KS: Right.

10:32   SN: And there are a lot of soils management techniques, that's something hold a lot of promise. Now one of the things that we really need to do is to understand not just what's possible in a kind of broad technical sense, that is, we look at one plot of land and try and extrapolate from that or some imagined global future. We really need to look at these sorts of ideas, afforestation, looking after soils, and stress test them. How do they actually fit into the world? Can we imagine politics and societies embracing those sorts of responses so that they actually work?

11:09   SN: On the direct air capture side, so that's at the very other end of that spectrum, there is some very small demonstration projects. One well-known demonstration project is taking place in Iceland. It's being run by a company called Climeworks. And at the moment, they're taking about 50 tons of carbon dioxide, five-zero tons, not 50 billion, five-zero tons of carbon out of the atmosphere per year into storage. Which is about equivalent to the emissions from one US household. Right, so it's just a very small scale demonstration project at this point.

11:45   KS: So Simon, we've got a feature here on Big World where we ask our guests to take a few minutes and blue sky a little bit. It's sort of an "if I ran the world" type question, and it's called, "Take Five." Here it is. If you could right now single-handedly institute five policies or practices that would change the world for the better in your area, what would they be? So Simon, in the carbon removal or broader environmental space, what five things would you do if you ran the world?

12:15   SN: Interesting, Kay. So let me start then with a couple of kind of big environmental things. So one thing that I often say to my students and to others who I speak to is that we need to break away from this notion that individualized or individual action is the way to save the world, right? And so the way that I kind of get at this point is to say to folks, recycling doesn't matter. That always annoys people, because everybody who cares about the environment knows that recycling is a good thing. But what I'm driving at with that is that given the magnitude of the challenges that we face now, to imagine the conversations about paper versus plastic at the supermarket or driving our Priuses to recycling depots is what environmentalism needs to be is just way too short sighted. So we need a different sort of environmental conversation that gets at big structures and the sort of things that need to be changed so that we can all live more sustainably on the planet.

13:04   SN: The second big connector thing is to stop letting business write the rules. Big business is going to be, has to be, a positive environmental force into the future. We need to find ways to embrace the business community and to get business pulling towards a more sustainable future. But letting business from their current positions write the rules of the road for environmental action is just destructive in all kinds of ways, right? Because businesses don't work with sustainability as their priority, they work according to a profit motive, and that's what's driving us into a deeper and deeper environmental distress. 13:41   SN: That's two things.

13:41   KS: Yeah.

13:42   SN: So three quick things on climate change and carbon removal in particular. The first thing that we need on climate change and on carbon removal is a much more robust and honest assessment of what the 1.5 degree target, which is in the Paris Agreement, actually requires of us. The international community has agreed to try, and limit warming of the planet. So no more than two degrees above pre-industrial averages, and to strive to do everything we possibly can to keep warming to 1.5 degrees.

14:11   SN: At the moment, that 1.5 degree target is not being assessed by the environmental community and by policy makers in a careful enough a way. We need to understand what it really entails for the sorts of actions that need to be taken.

14:23   SN: A related point is that we need a large-scale coordinated research program internationally, but it could be led by US government into the future, where we look at what's possible in terms of carbon removal in particular. What's actually there? That's kind of understand it, let's work out what's possible and plausible, and how to assess it, and how we kind of bake it into the climate change response portfolio, if indeed it's something that proves beneficial.

14:52   SN: The final thing is a little bit more arcane, but one of the things that's really required at the moment around carbon removal in particular, are strong rules for evaluation, for monitoring, and for verification. Otherwise this could just become the wild west. There are lots of people make promises about pulling carbon out the atmosphere and putting it underground. Unless we have really careful methods and methodologies for working out whether carbon is staying in the ground long term, then you could be paying a bunch of people a bunch of money to develop projects without any benefit to the climate. So getting the rules right around evaluation, monitoring, verification should be a national priority, and really should be a priority and is becoming a priority in the international conversation.

15:34   KS: So some themes there of international cooperation, getting real with the rules, and getting real with the measurements.

15:42   SN: There you go.

15:42   KS: Yeah. Awesome.

15:49   KS: So here's a hypothetical, and this is intended to kind of get us into the space of if this kind of thing were to work, what happens next? So hypothetically, if Thailand, for example, builds a giant carbon vacuum and places it in the middle of Bangkok, is it reasonable to think that the scale of that could be such that neighboring countries like Laos or Cambodia might reap some of the benefits of that initiative? And then could Thailand then impose political or financial obligations on their neighbors to pitch in? As we're speaking hypothetically. Basically, are there ways to encourage cooperation between countries most affected by carbon emissions with carbon removal specifically? Quite a hypothetical, it's a throat-clearing hypothetical.

16:37   SN: So there are some really interesting dimensions of the hypothetical. So the first thing to say is that with the climate change challenge, carbon dioxide remove from any place is good for all other places, right? So if we're emitting carbon dioxide in the United States, that's not just a US problem, that's a global problem. And so if you flip that around, taking carbon out of the atmosphere over Bangkok is going to be of benefit to the whole planet.

16:37   KS: Right.

17:04   SN: Right? And so that's an interesting dimension of the carbon removal conversation which makes it a little different than lots of other global challenges. And so if Thailand were to institute a gigantic program of a big plant, then the international community would be reaping benefits, and so therefore Thailand might reasonably ask for other countries to contribute.

17:23   KS: Not just the neighboring countries?

17:25   SN: Not just the neighboring countries, like the rest of the world, right? And so one of the big conversations in climate circles writ large has been about technology transfer and payments from the Global North, that is rich countries, to the Global South. And here's another place where that might be an important consideration.

17:38   SN: Now another interesting thing about the hypothetical is that if Thailand were to build a gigantic plant in the middle of Bangkok, you might be able to pull the carbon down in Bangkok, but you need a place to put it. Right? And so with carbon removal there are two steps. First you need to pull the carbon out of the atmosphere, and then you need to store it somewhere.

17:55   SN: So if the plant were in the middle of Bangkok, it's unlikely that there were aquifers, saline aquifers or old oil wells under Bangkok that could be used to store liquid carbon. And so it would have to be put into a pipeline and moved somewhere.

18:10   SN: So that's a dimension that people are now setting to wrestle with. What's the nature of the industrial undertaking, not just to pull carbon out of the atmosphere, but to move it around and put it into long-term storage?

18:22   KS: Safely, yeah. That's a huge infrastructure, yeah.

18:25   SN: And basically in perpetuity. You can't just put it underground so that it leaks out over the next couple of decades. It's going to be put into a geologic storage that keeps it there for the foreseeable future.

18:36   KS: I mean, do we even have any idea how large something would have to be, an aquifer, to store an amount approaching the billion numbers that you're giving out for making a real difference?

18:50   SN: Well, that's one of the open research questions, so that there are numbers kind of floating around about how much might be stored in particular land masses. That is if we look across the continental United States, we have a reasonable sense of underground geologic formation. People can look at some of these small-scale experiments and try and extrapolate from those about what could be stored safely over the long term. But in most countries, we just don't have a good sense about what might be possible.

19:16   KS: Interesting. So continuing to talk about international cooperation since this is sort of at the scientific stage, is there any agreement or has there even been any discussion among policy makers nationally or internationally or within global governance institutions like the UN about how to structure carbon removal strategies, whether at the more biological and or at the more technological end?

19:42   SN: In certain respects, the conversation is pretty well advanced, and in other respects, the conversation is just getting started. So in terms of the conversation being pretty well advanced, there has been an ongoing conversation in the international climate change response process under the UN framework convention on climate change and obviously the Paris agreement about avoiding emissions from deforestation. And so there's a kind of long-standing program at the international level about trying to plant more trees and about making sure that payments go to those communities that are keeping forests intact.

20:13   SN: There's also been a pretty robust conversation about soils management that was really advanced during the negotiation of the Paris agreement. When it comes to just thinking more broadly about carbon removal as a portfolio or strategy style, it is sort of pretty nascent international conversation. With the Paris Agreement, we see that the international community has agreed to strive by mid-century, that is about 2050, for net negative emissions or a balancing of emissions.

20:43   SN: Right? So again thinking about what it means to kind of treat climate change as a challenge. It's about putting greenhouse gases into the atmosphere.

20:52   SN: And so the first thing you need to do is just turn off the spigot. Nothing that we're talking about is any kind of magic get out of jail free card, right? And that's something I wanted to make sure to come back to Kay, and so maybe I can just talk about that briefly at the moment.

21:05   KS: Absolutely.

21:06   SN: Right. One of the interesting things about this whole conversation is that even having the conversation about carbon removal can be a little dangerous or counterproductive.

21:15   KS: Because it seems like an easy way out without having to deal with the emissions.

21:18   SN: Yeah, exactly. And it's so easy to kind of couch it that way. At some point, some really smart person or some really kind of innovative company is just going to come up with the magic fix.

21:27   KS: The magic bullet that will save us all.

21:30   SN: Exactly, and so why do the work now of changing lifestyles and economic systems? I mean, that's going to be extraordinarily disruptive and costly. Right? Why do that hard work if just over the horizon is this magic technology that will save us all?

21:44   KS: That particularly plays into the American view of itself, American exceptionalism that our ingenuity will always save us.

21:50   SN: Yeah. Right. And so even to have this conversation is seen by some as legitimating something that may not come to fruition, which could be a dangerous thing. My own view is that, at the same time, we already have this notion floating around that these technologies might some day materialize, and it's already shaping climate politics. And so my own sense is that, it's much better to have this conversation about where the carbon removal might be something that could be used, have that conversation early and do kind of really robust assessment to look at what's possible. That that might be a more beneficial thing.

22:25   SN: And so kind of back to the thread, even before we do that assessment, international community has agreed in the Paris Agreement to strive for net-zero or net-negative emissions by mid-century, which means as they put it in the agreement, balancing sources and sinks. And so carbon removal, that is sinks, places where you would put carbon, either into biological storage or through these chemical pathways, is already there, it's already in the Paris agreement.

22:52   SN: At the moment, the international community is basically writing the rules by which carbon removal might be integrated into the promises that countries make about their climate actions. So this is actually a really kind of interesting and important time for the international community as it wrestles with carbon removal as a potential pathway.

23:11   KS: And probably a time in which we might well be served to have been in the Paris agreement as the US that is.

23:11   SN: With the US?

23:21   KS: Yes.

23:22   SN: Yeah, I'm going to cling to my accent.

23:23   KS: Yeah, I know.

23:27   SN: And, even though I've been here a long time, pretend to be an outsider when it comes to that conversation.

23:30   KS: Yeah. So pulling back just a bit. I want to ask you more broadly about attitudes. So how do you as an environmental scholar remain optimistic? And how can anyone listening to this not sort of feel like Eeyore you know, that there's little dark cloud and we can't escape it, and that all of this innovation is tinkering around the edges, and that humanity making all these necessary changes is just very unlikely. So basically, how can you convince me that humanity has a future?

24:01   SN: So here's my line of optimism which I borrowed from David Orr, who's another environmental scholar. So David once said that if you consider the environmental situation and you're optimistic, you don't know enough. But if you're pessimistic, then you're ineffective. So you don't have the luxury of pessimism. And so what David and lots of others say is that you need to strike the balance. You need find hope, which is in between optimism and pessimism.

24:26   SN: So the way that David puts it, optimism is the resource that you can cultivate and draw on when the odds are in your favor. Hope is what you need to generate when the odds are stacked against you. This is an extraordinarily difficult situation that we find ourselves in, to imagine that tackling climate change is somehow an easy thing, that we'll find pathways that are win, win, win for every single person, and every single biological system into the future. We're past that point, we're dreaming. It's going to be hard. But to imagine that it's impossible is debilitating. Right? And so we need to cultivate hope.

24:59   SN: I think the carbon removal conversation can be a hopeful conversation. If it's optimistic, that is it's blindly taking us into the future, imagining that it's not going to be difficult, then that would be problematic.

25:12   KS: Right.

25:12   SN: So the generation of hope around carbon removal comes from really hard-headed assessment. We need to know what's there.

25:20   KS: Despair is paralyzing, hope is motivating, and we basically need to roll up our sleeves and get to work.

25:26   SN: That's it.

25:27   KS: Okay. Simon, thank you for joining Big World and being our first guest on Big World and walking us through carbon removal. Big World is a production of the School of International Service at American University. Our theme music is "It Was Just Cold" by Andrew Codeman. Until next time.

Episode Guest

Simon Nicholson, professor at SIS, director of SIS's Global Environmental Politics program, director of the Institute for Carbon Removal Law and Policy.

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