American Airlines will pay to bury 10,000 tons of CO2 underground

American Airlines signed a deal to trap 10,000 tons of carbon dioxide underground. It’s part of the airline’s plans to limit the pollution causing climate change, and it marks the first major deal for the Bill Gates-backed startup Graphyte that’s developing cutting-edge technology to tackle the problem.

Similar startups are selling services to big brands that want to draw down some of the planet-heating emissions they release into the atmosphere. They’re developing technology that filters CO2 out of the air or seawater — equipment that’s so expensive that it hasn’t been able to scale enough to make a meaningful dent in carbon emissions.

Graphyte is unique because it relies on a seemingly simple process to permanently store carbon underground, making its strategy way more affordable than its competitors. With a giant like American Airlines as its first customer, Graphyte has a chance to prove whether its technology can overcome challenges other carbon credit schemes face.

Graphyte claims that it can capture carbon for the low, low price of $100 per ton. For comparison, the largest carbon dioxide removal plant operating today captures CO2 for companies including Microsoft, Stripe, and Shopify for around $600 a ton. Considering American Airlines produced the equivalent of 49 million metric tons of carbon dioxide in 2022, you can see how carbon removal costs can balloon.

Industry insiders often point to $100 a ton as the goal for making carbon removal technology affordable enough to scale. How has Graphyte hit that mark? It claims to use significantly less energy than its competitors. Running machines that suck CO2 out of the atmosphere or oceans tends to use a lot of electricity, an issue that drives up costs and can even limit how much good they do for the climate without access to ample clean energy sources.

Graphyte has a totally different tactic, which it calls carbon casting. Essentially, it’s a way to mummify plant matter — preventing it from decaying, which would otherwise release carbon dioxide that the plants absorbed when they were alive through photosynthesis. The company starts by collecting biomass, which, in this case, is waste from agriculture and timber production. Then it dries the plant material, preventing decomposition by getting rid of any moisture and microbes. After that, the biomass gets tightly packed into bricks and wrapped in what Graphyte says is “an environmentally-safe, impermeable barrier to ensure that decomposition does not restart.” Bury those bricks underground, and Graphyte says it can store the carbon dioxide those plants took in during their lifetime for a thousand years.

The first commercial deployment of this method for American Airlines will take place at Graphyte’s facility in Pine Bluff, Arkansas. The company also has financial backing from Gates’ climate investment firm, Breakthrough Energy Ventures.

The deal is for Graphyte to capture and store 10,000 tons of carbon for American Airlines by 2025, with carbon removal credits issued to represent each ton of carbon removed. Those credits resemble similar carbon offsets tied to forests or tree planting schemes, programs that have been criticized for failing to result in real-world reductions in greenhouse gas pollution. Emerging credit markets for methods to remove CO2, like carbon casting, will have to prove that they can get their accounting right. In other words, they’ll have to show that new projects actually permanently trap CO2 that otherwise would have wound up in the atmosphere.

Moreover, it doesn’t do any good for a company to rely entirely on capturing carbon dioxide to fight climate change. Even at $100 a ton, it gets inordinately expensive to try to capture or offset tens of millions of tons of CO2 pollution each year. And the science is clear that tactics like carbon removal are only a supplement to the real cure for climate change: preventing the pollution in the first place by dropping fossil fuels and turning to clean energy. For its part, American Airlines is also working on transitioning to sustainable aviation fuels and even reducing airplane contrails that exacerbate global warming.