“Olivine is this green rock here. What's special about it is that when it interacts with water and CO2, it causes the CO2 to turn into what corals use to build their skeletons. So, when it breaks down, we can turn CO2 into shells and permanently store them in rock in the sea floor."
Project Vesta is not a typical industrial-sized carbon removal process, in which vast amounts of CO2 are sucked from the atmosphere and stored underground.
But it’s one of several early-stage capture projects sharing in a million-dollar investment from Stripe.
The San Francisco electronic payments firm chose more costly innovation, instead of simply paying for cheap offsets from the likes of landowners who agree not to cut down their trees.
Eric Matzner is from Project Vesta: "Step 1 of Project Vesta is to locate a reserve of dunite, which is a formation of 90 percent pure olivene. Once we find that location, step 2 is to minimally grind and transport it to a nearby coastline. Step 3 is to put that rock in a thin layer on the beach in the tidal area where the waves will grind it down into small sand and the collisions will rapidly accelerate the weathering process, which sucks up CO2."
Stripe’s commitment is small compared to the size of the global task. But it is having an impact. Microsoft was impressed, and has since announced a $1 billion investment in carbon removal.
Another Stripe beneficiary is Charm Industrial, which takes biomass which would otherwise decompose, and produces bio-oil which is then stored underground.
Peter Reinhardt is a co-founder: "Yeah. At the most basic level, we're taking waste agricultural residue. /edit/ heating it up without oxygen, so without air, and that causes it to turn into solid ash and a liquid called bio oil. And that bio oil contains almost all the carbon that came from the carbon dioxide in the atmosphere. And now we take that carbon by oil and pump it underground into a waste disposal wells."
There is a note of caution though.
Some environmentalists warn that alternative carbon removal can distract from pushing for more significant emission cuts.
And that scaling up small greenhouse gas capture projects may turn out to be energy-inefficient or actually harm the planet.