IRA FLATOW: This is Science Friday. I’m Ira Flatow. We’re continuing our conversation about ways to battle the climate crisis. One of the technologies highlighted in the latest IPCC report is carbon removal, not to be confused with carbon capture. CO2 removal is a process that absorbs CO2 already in the atmosphere and stores it elsewhere. Capture is removing it from smokestacks, for example, before it gets into the air.

CO2 removal is a new technology, but it has some climate scientists worried about pouring money into this new tech in lieu of cutting back on the reliance on fossil fuels. Joining me now to talk more about the pros and cons of carbon removal is my guest, Amar Bhardwaj, energy technology policy fellow at the International Energy Agency. Welcome to Science Friday.

AMAR BHARDWAJ: Hi, Ira. Great to be here.

IRA FLATOW: Nice to have you. OK, so carbon removal is when you suck out CO2 from the atmosphere. You store it somewhere. How many different ways can you do that?

AMAR BHARDWAJ: There is a whole range of different approaches to do that and even more that are being innovated, even as we speak. But they broadly fall into three rough categories. So the first is engineered carbon removals. These are more on the technological side, and the prime example of that is direct air capture, which is probably the most well-known of those engineered solutions, where air is blown over some material that’s engineered to grab the CO2 out of the ambient air.

And then some form of energy input is needed to re-release that CO2 from that material and then store it underground or use it for some other purpose. Another class of carbon removals is more biomass-based carbon removal, which essentially entail growing plants and allowing them to photosynthesize, incorporate CO2 into their structures, and then use that as a form of removal and then use a plant’s biomass either to store the CO2 underground or use for some other purpose. And that can happen through afforestation or reforestation, just growing trees, or it can also happen in oceans, growing algae for the same purpose or a range of other ways.

And then the third category is carbon mineralization, which is a reaction by which CO2 is uptake into mineral form, and that can happen through a lot of different methods, through industrial waste streams that are good for that reaction. It can happen through rock formations that exist naturally in the world that naturally do this mineralization reaction, but are engineered to do the reaction faster.

IRA FLATOW: Well, let’s talk about what scale we are at now and where we get to go, where we need to go.

AMAR BHARDWAJ: These are some crazy numbers in terms of the difference between where we’re at now in terms of the scale of carbon removal and where we’re looking at over the coming decades. So right now, for reference, the biggest carbon removal project or installation that exists is something called the Orca plant by a company called Climeworks. The plant is based in Iceland. And this is a direct air capture plant, like I mentioned earlier, that removes 4,000 tons of CO2 per year from the atmosphere.

And that might sound like a decent amount, but it’s very, very minuscule compared to the scale that we’re looking at in the future. The scale for getting to net zero emissions that many different agencies or analysts have centered on, at least in a broad sense, is gigatons of CO2 removed from the atmosphere per year by mid-century. So that’s billions of tons of CO2. So there is a lot of growth that’s going to have to happen in the industry in order to reach those sorts of levels of carbon removal.

IRA FLATOW: Amar, how much will all of this cost?

AMAR BHARDWAJ: Yeah, we’re looking at some big numbers. So right now, with some of these engineered solutions, for example, it might be around $600 per ton of CO2 removed. For more biomass-based solutions, that can be cheaper.

The target that many have agreed on is getting costs down to $100 per ton of CO2. So if we imagine, we have $100 per ton large-scale carbon removal and we’re removing billions of tons of carbon per year, that is a couple hundred billion dollars per year just to keep that industry running, just to keep removing the CO2. We would also need all the money that’s required to get to that point.

IRA FLATOW: So it’s a major commitment, but I guess if you balance that against not doing anything and what happens to the planet and all the people living on it, it may not seem like such a big amount of money after all.

AMAR BHARDWAJ: Oh, yeah. No contest compared to the cost of not doing anything and just dealing with the consequences of the climate crisis.

IRA FLATOW: I mean, this sounds to me like we have a long way to go on this, don’t we? I mean, I guess I’m saying it’s not very practical right now.

AMAR BHARDWAJ: We will definitely need a pretty wide range of these different forms of carbon removal solutions, and we should think about the limits to scale for each of these different methods. So for example, with afforestation or reforestation, you only really want to be growing forests in places where forests are supposed to grow, where it makes sense ecologically. A very similar example is bioenergy with carbon capture and storage, where you’re growing crops or plants that are sucking out CO2. That will require huge amounts of land to grow the crops.

Basically, with all these different carbon removal solutions, there’s going to be some level of infrastructures that are required to be built to support them. There will be a lot to grapple with in terms of the impacts of those huge infrastructures that we’re going to be building. Often, we’ve seen that with the infrastructures we have now in the fossil energy system, they are disproportionately impacting communities of color that are put in the way of these infrastructures. And when they fail or when they create pollution, they are the ones that are going to be adversely impacted by that.

IRA FLATOW: The big emitters, like the fossil fuel companies, are getting into the carbon removal business, are they not? I mean, is this a sincere business-like effort, or is it a greenwashing effort?

AMAR BHARDWAJ: The fossil fuel industry is definitely very well-positioned to use the growth of carbon removal to say we can continue extracting our fossil fuels and selling them. And the emissions from that aren’t going to be as much of a problem because we can just cancel them out with carbon removal. So in one sense, the carbon removal industry that’s being stood up begins to serve as a piece of the social imaginary, so to speak, that the public or politicians can think, this will be available in the future, these large amounts of carbon removal, that make it easier for us to continue emitting the way we are now.

I think another piece of that influence that the fossil fuel industry can have is with actually working with carbon removal companies, purchasing them or funding them and, in one sense, using that involvement to, like you say, greenwash and say that they are fully committed towards decarbonizing, reducing fossil fuel use while they continue to pour most of their expenditures into fossil fuel exploration and extraction, but also, in terms of directing the industry, the carbon removal industry in a direction that’s favorable to them.

And one example of that is, like I mentioned, these carbon removal facilities use a lot of energy. And that could come from low carbon resources, like low carbon electricity, for example, which would be pretty necessary for allowing the CO2 remove– to actually be CO2 that’s net removed from the atmosphere. But you could also power these with natural gas, and there’s no law stopping you from doing that.

And so if we have a carbon removal industry that, through the influence of the fossil fuel industry, ends up getting built up to consume huge amounts of natural gas, for example, that’s a win on multiple fronts for the fossil fuel industry and damages the efforts and good faith to get towards net zero emissions and reduce fossil fuel use.

IRA FLATOW: This week, there was actually a nearly $1 billion investment in the CO2 removal industry. Tell me more about the investment details.

AMAR BHARDWAJ: Yes. So this was what’s called an advance market commitment that was organized by an online payments company called Stripe with funding from Alphabet, Meta, and a few other companies. And they basically committed to buy almost a billion dollars worth of carbon removals. So it’s called an advance market commitment because there is not a billion dollars worth of carbon removals available right now to buy, but it provides a really strong demand signal for companies that are entering the space that there will be a buyer in the future when they get there.

With these sorts of investments and with the overall general momentum and hype that’s being built around carbon removal and that there is some risks along the lines of potentially creating some sort of bubble in the carbon removal industry with all the excitement that this is going to be this huge thing that’s going to start working very soon, there’s a sense that we don’t really allow for these technologies to experiment, to fail, to iterate because they’re such new technologies for moving carbon.

We need that level of the leeway towards failure. That might be a little bit counterproductive when we have these huge amounts of money and these messaging pouring in that this is going to be big very soon.

IRA FLATOW: Are you feeling optimistic in the long run that this could make a dent in carbon in the atmosphere?

AMAR BHARDWAJ: That’s a loaded question, and it’s one that I definitely think through a lot these days. I think that there are a couple parts to that question. I think one is about whether we achieve the scale that we need. Seeing the momentum now and all the innovation that’s happening in this space, there’s a good chance that we can reach maybe a couple gigatons of CO2 removal per year.

And I think another side of it is when we reach that gigaton scale industry, what does it actually look like from a social or political or justice perspective? Is it an industry that’s basically replicating the scale and impact of the fossil fuel industry now, where it’s trampling on communities of color, where it’s entrenching fossil fuel use, where it has political systems beholden to it?

Or is it a system that is co-produced with the communities around it, where those communities are benefiting from this carbon removal infrastructure, where it’s compatible with reducing fossil fuel use? I think that is a much harder outcome to achieve than just the scale itself and requires a lot of forethought starting now to get to that point.

IRA FLATOW: Well, I want to thank you for elucidating all those options in the future and taking time to talk with us.

AMAR BHARDWAJ: Oh, thanks very much, Ira

IRA FLATOW: Amar Bhardwaj, energy technology policy fellow at the International Energy Agency that’s based in Paris, France.

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