The Surprising Climate Fix That Tech Companies Spent Millions On: A Simple yet Effective Solution in the Form of Rocks

In an effort to mitigate the impact of their pollution on the climate, Google and several other big companies have partnered with a startup called Terradot to trap carbon dioxide using rocks. This multimillion-dollar deal involves removing 90,000 tons of carbon dioxide from the atmosphere, with the goal of slowing down climate change.

The Deal

Google, H&M Group, and Salesforce are among the companies that have collectively agreed to pay Terradot $27 million to remove 90,000 tons of carbon dioxide from the atmosphere. The deals were brokered by Frontier, a carbon removal initiative led by Stripe, Google, Shopify, and McKinsey Sustainability.

Separately, Google has announced its own deal to purchase an additional 200,000 tons of carbon removal from Terradot. While both companies declined to reveal how much this deal is worth, if the cost is similar to the Frontier agreement – roughly $300 per ton of CO2 captured – it could add up to $60 million. However, Google says that it expects the price to come down over time for this larger deal.

What is Enhanced Rock Weathering?

Enhanced rock weathering (ERW) is a relatively low-tech tactic for taking carbon dioxide out of the atmosphere. This strategy attempts to speed up a natural process that might otherwise take thousands of years. Rainfall naturally ‘weathers’ or breaks down rock, releasing calcium and magnesium and triggering a chemical reaction that traps CO2 in water as bicarbonate. Groundwater carrying that bicarbonate eventually makes its way to the ocean, which stores the carbon and keeps it out of the atmosphere.

Accelerating this process is simple: crush up rock and spread it out over a large area, increasing the surface area of exposed rock that reacts with CO2. Terradot uses basalt from quarries in southern Brazil to nearby farms, where farmers can use the finely-ground basalt to manage the pH of soil, and carbon removal is a bonus.

The Challenges Ahead

Terradot has a 2029 deadline to make good on the 90,000-ton Frontier deal. It’s supposed to capture an additional 200,000 tons for Google by the early 2030s. However, the tricky part will be trying to count how much CO2 Terradot actually manages to trap.

Google admits that right now, it’s hard to measure with precision how much CO2 this process removes from the atmosphere. But the only way to develop highly rigorous measurement tools is to deploy this approach widely in the real world. That’s why Google’s support aims to help Terradot’s solution get out of the lab more quickly.

The Uncertainty Remains

Terradot says it’ll take soil samples to assess how much CO2 is captured based on how the rock degrades over time. However, it’s harder to figure out how much calcium, magnesium, and bicarbonate makes it to the ocean to permanently sequester CO2. Fertilizer in the soil can also potentially limit how much carbon is captured through enhanced rock weathering.

The Outstanding Question

"How much they sequester is still the outstanding question," says Dr. Jagoutz, a geologist at Harvard University. "But he doesn’t think that uncertainty needs to stop trials in the real world. ‘I also think, why not try? … I don’t think we have the luxury to overthink it right now.’"

The Limits of Carbon Removal

While carbon removal can help counteract some of a company’s legacy of pollution while they make the energy transition, switching to clean energy is the only effective way to stop climate change. Carbon dioxide emissions from fossil fuels are already making heatwaves, droughts, wildfires, storms, and other climate disasters more dangerous.

Google’s carbon footprint has grown as it builds out energy-hungry AI data centers. The company has recently announced plans to help develop advanced nuclear reactors and new solar and wind farms to power its data centers with carbon pollution-free electricity.

The Verdict

"It’s very clear that this is not a substitute for emissions reductions at all … we need both of these tools," says Kanoff, the CEO of Terradot. "Any of the partners we’re even thinking about working with, they have some of the most aggressive emission reduction strategies of any of the companies really in the world. And those are the groups that we really want to partner with to advance carbon removal."

As the climate crisis continues to worsen, it’s essential for companies like Google and Terradot to work together to develop effective solutions to remove CO2 from the atmosphere. While there are still challenges ahead, this partnership is a step in the right direction towards mitigating the impact of pollution on the climate.

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