The companies have struck a deal with startup Lithos, which offers CO2 capture services using the tactic of enhanced “weathering,” the natural ability of rocks to absorb carbon dioxide as they break down.
Lithos was signed by Frontier, a decarbonization initiative led by Stripe, Alphabet, Shopify, and McKinsey Sustainability, along with Autodesk, H&M Group, JPMorgan Chase, Workday, Zendesk, Canva, and Boom Supersonic.
Lithos bets on alkaline rocks that absorb CO2 from the air during mechanical destruction. In nature, this process occurs under the influence of rain, wind or sea waves and can last thousands of years without outside help. To speed up the process, rocks (such as basalt or gravel) can be ground into dust and spread over a large area, thereby threatening to absorb more CO2.
Lithos is already testing the technique in farm fields, where crushed basalt subsequently reacts with rainwater, trapping carbon dioxide in the air as bicarbonate, which then travels through groundwater to the sea, where Lithos expects it to persist for at least 10,000 years or longer.
The difficulty is that Lithos must report to the companies how much CO2 the rocks have captured. The company says it makes estimates through soil samples, measuring its chemical composition (a process made possible by research at Yale University).
“The Lithos method is an incremental improvement, but it still has serious unsolved questions,” says Oliver Jaguts, a professor of geology at the Massachusetts Institute of Technology.
The data provided by the company essentially shows the “absolute maximum estimate of what could happen,” but the reality is, unfortunately, much more complex, Jaguts adds. In particular, there is a risk of overestimating how much carbon dioxide is sequestered if the full effect of soil fertilizers on the process is not taken into account.
There are other possible side effects when using enhanced weathering tactics. The concentration of bicarbonate in any particular area can have negative consequences for ecosystems. The environmental impact of mining, crushing and transporting rock should also be considered (Lithos uses quarry waste to minimize this impact).
According to Frontier, the $57.1 million deal with Lithos should cover the cost of sequestering more than 154,000 tons of CO2 by 2028 (the equivalent of taking about 34,000 cars off the road for a year). At about $370 per ton of CO2 removed, it’s still a pretty expensive price, although it’s significantly cheaper than the prices of companies that capture carbon dioxide from the air ($600 per ton).
The first commercial plant that will “suck” CO2 from the air – with further storage underground – was built in the USA
Source: The Verge
