Reducing the global carbon footprint will take more than just switching to electric vehicles or turning off lights to save energy. It also means removing carbon directly from the air.
Of the existing methods, planting trees is perhaps the best known, but there are drawbacks. For example, in the event of a forest fire, the carbon stored by the trees is released into the air. Moreover, some fear that there is just not enough space to plant the number of trees needed to make a real dent in climate change.
However, companies and laboratories are experimenting with other methods. A startup, Legacy Carbon Technologies, is working on a method that extracts carbon from the air using the same process in nature that creates limestone. The carbon can then be stored permanently, or even used in other materials like concrete.
Adele Peters is a senior writer for Fast Company which Newly profiled heirloom. She discussed the future of the carbon capture industry with Marketplace’s Amy Scott. An edited transcript of their conversation is below.
Amy Scott: OK, let’s start with the science. As simply as possible, explain to me how direct air capture works.
Adele Peters: The company I was looking at in the story, Heirloom, basically speeds up a process that happens naturally. So they use a powder made from crushed limestone, which is a rock that forms with the help of CO2. In nature, this takes millions of years, but they essentially do the same thing in about three days. They mix the powder with water and put it outside on what looks like baking sheets that are stacked in these big shelves. And since it sits there, the powder acts like a sponge for the CO2, pulling him very quickly out of the air. And when they recovered the CO2it may in fact be permanently stored elsewhere.
Scott: It’s just crazy. I mean, first of all, how you figure out how to do something in three days that normally takes millions of years is just mind blowing. But at this point, how much carbon dioxide are they able to capture with this method?
Rock : This still happens on a very small scale. So really, to start having a meaningful impact on climate change, it’s going to have to happen on a massively larger scale. And that’s kind of what they’re aiming for. By 2035, they want to be able to extract a billion tons of CO2 out of the air every year, which is basically the same as the airline industry’s annual emissions. So it’s a huge sum.
Scott: So that’s a little over a decade away. Is it realistic?
Rock : I mean, that remains to be seen. But I think the process they use is actually quite simple. And one of the big challenges they have now is just being able to afford to scale. And how they do that is sell carbon offsets, basically, to companies that want to offset their own emissions. And they need enough demand for them to really get to the level they need.
Scott: And how much does this technology cost? I mean, what kind of price are we talking about to do this at the scale needed?
Rock : It’s quite expensive now. What they are aiming for by 2035 is to be able to capture CO2 around $100 a ton. That’s a lot less than some of these other technologies are doing right now.
Scott: It’s tempting to get excited about this, especially when you read that global carbon dioxide emissions have continued to rise when we should be going in the exact opposite direction. And I was wondering, do you think there is a risk of betting too much on carbon removal and therefore not doing enough to reduce emissions in the first place?
Rock : Yeah, I think there’s definitely a risk that companies will say, ‘OK, we don’t need to cut emissions as quickly as possible, because we can look to offsets or carbon removal instead .” And it certainly does not replace the need to reduce emissions. But to meet climate targets, if you look at the models, countries are going to have to make huge emissions cuts and remove carbon from the air. They have to do both things, basically. So one study said that by mid-century we may need to remove up to 10 billion tons of CO2 every year. And that’s on top of everything that needs to change, like switching to electric vehicles and renewables and eliminating emissions as well.
Scott: You cover climate change, among other topics. What hope does this technology give you? Or do you think it’s still too far to really expect this to solve this massive crisis?
Rock : I think it’s still early days, but I’m actually optimistic both about this and about our ability to reduce emissions. Most of the technology we need already exists and somehow needs to be implemented. So I think there’s a lot of reason for hope.
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