Tech companies spend millions on a proposed climate fix that turns rocks into fuel.

In an effort to counteract the impact of their pollution on the climate, Google and other big companies have invested in a plan to trap carbon dioxide using rocks. This initiative, led by Stripe, Google, Shopify, and McKinsey Sustainability, involves partnering with startups that specialize in enhanced rock weathering (ERW), a relatively low-tech tactic for taking carbon dioxide out of the atmosphere.

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Multimillion Dollar Deals with Terradot

Google, H&M Group, and Salesforce are among several companies that collectively agreed to pay $27 million to remove 90,000 tons of carbon dioxide from the atmosphere through Terradot, a Sheryl Sandberg-backed startup. This deal was brokered by Frontier, a carbon removal initiative led by Stripe, Google, Shopify, and McKinsey Sustainability.

Google’s Additional Deal

Separately, Google announced its own deal to purchase an additional 200,000 tons of carbon removal from Terradot. While the company declined to disclose the exact cost of this deal, it is estimated to be around $60 million, assuming a similar price per ton as the Frontier agreement.

Enhanced Rock Weathering: A Natural Process

Enhanced rock weathering attempts to speed up a natural process that occurs over thousands of years. Rainfall naturally "weathers" or breaks down rocks, releasing calcium and magnesium and triggering a chemical reaction that traps CO2 in water as bicarbonate. Groundwater carrying this bicarbonate eventually makes its way to the ocean, where it is stored and kept out of the atmosphere.

Terradot’s Strategy

Terradot takes basalt from quarries in southern Brazil to nearby farms, where farmers can use the finely-ground basalt to manage soil pH, and carbon removal becomes an added benefit. The startup has partnered with Brazil’s agricultural research agency (EMBRAPA) to use this strategy on over one million hectares of land.

Challenges Ahead

While Terradot’s approach shows promise, there are several challenges ahead. One of the main concerns is measuring the amount of CO2 trapped by the process. Google admits that it is currently difficult to measure with precision how much CO2 is removed from the atmosphere through ERW. However, the company believes that deploying this approach widely in the real world will help develop more rigorous measurement tools.

Uncertainty and Limitations

Experts are also concerned about the potential limitations of enhanced rock weathering. For instance, fertilizer in the soil can limit how much carbon is captured through this process. Additionally, there may be uncertainties surrounding the amount of calcium, magnesium, and bicarbonate that makes it to the ocean to permanently sequester CO2.

Jagoutz’s Perspective

Dr. Jagoutz, a geologist at Harvard University, believes that these challenges should not prevent us from trying out ERW in the real world. "I also think, why not try?" he says. "We don’t have the luxury to overthink it right now."

Google’s Carbon Footprint and Climate Change

Despite its efforts to reduce carbon emissions through enhanced rock weathering, Google still has a significant carbon footprint. The company has grown its energy-hungry AI data centers, which contribute to climate change by emitting greenhouse gases. In addition, switching to clean energy is the only effective way to stop climate change.

Conclusion

While Google’s investment in enhanced rock weathering is a step in the right direction, it is essential to remember that carbon removal is not a substitute for emissions reductions. Any company looking to partner with startups like Terradot should have aggressive emission reduction strategies in place.