The U.S.’s first direct air capture plant recently opened in California.
Direct air capture is a way pull CO2 out of the atmosphere, hopefully reversing some of the effects of climate change.
The process is still expensive and slow, but it’s a step in the right direction for climate change mitigation.
It’s no secret that our planet isn’t in the best shape right now. Temperatures are skyrocketing, ice sheets are shrinking, and natural disasters are on the rise. It’s not that attempts aren’t being made to fix things and calls aren’t going out to do more, but things aren’t shifting fast enough to curb the effects we’re already feeling.
It’s not fun to read about, it’s not enjoyable to confront, and it’s not easy to fix. But some people are trying—people like the ones behind Heirloom Carbon Technologies, a startup set on reversing some of the greenhouse gas pollution that got us into this mess in the first place. They just opened the United States’ first direct air capture plant, and they hope it won’t be our last.
“We want to get to millions of tons per year,” CEO Shashank Samala told The New York Times. “That means copying and pasting this basic design over and over.”
But what exactly are they copying and pasting? What is direct air capture? Well, the idea—which has been around for a while—is basically that we could somehow “scrub” the air to take out the excess carbon dioxide (CO2), store that CO2 away, and be left with a cleaner, less-polluted atmosphere. It’s just one proposed method of carbon capture, and it’s a popular one.
The concept is simple, but developing a way to actually do this has not been quite as easy—largely because it’s hard to get technologies like this to work relatively cheaply and efficiently on a big enough scale to actually make a dent in the problem. While it’s certainly not cheap, Heirloom’s method seems to be at least plausibly “scalable” enough that they’ve received the investments needed to start trying their tech out in plants instead of labs. The first plant is in Iceland, and the newest is in California.
That tech? Rocks. Granted, they are rocks that are being manipulated in a very high-tech way, but still… rocks.
In order to bind carbon into a form where it can be removed permanently from the atmosphere, experts basically take limestone apart and put it back together again. They start by heating limestone to 1,650°F. This releases CO2(which is sucked away and stored in a tank) and leaves behind calcium oxide. That calcium oxide, now ready to bond with more CO2 and create new limestone, is wet and placed on racks that are exposed to the open air for a few days. And once that period is over, and the calcium oxide has bonded with as much CO2 as it can hold and turned back to limestone, the process begins again. The CO2 that was pulled out of the air and ended up in a tank then either (for the U.S. plant) ends up mixed into concrete, where it mineralizes and can no longer return to the atmosphere.
Now, as cool as this sounds, it has a few downsides. For one, even though this new plant is substantial in size, it’s still only extracting a small fraction of what is produced every day. And it’s expensive to run—direct air capture like this currently costs about $600-$1000 per ton of CO2 removed. For context, according to the International Energy Agency, we (as a planet) pumped 36.8 billion tons of carbon into the atmosphere just last year.
Cost and speed also aren’t the only concerns. Environmentalists worry that ultra-polluting industries like oil and coal will see the ability to remove carbon from the atmosphere after the fact as a reason to simply not worry about reducing emissions in the first place.
But there is no magic bullet when it comes to climate change. Most likely, getting ourselves out of the mess we’ve gotten ourselves into is going to take a combination of approaches—reducing emissions and scrubbing the air among them. Hopefully, if we’re able to combine enough of these techniques with real intention and efficiency, we’ll stop the climate from getting as bad as it could get.
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