According to Jim Mann, cofounder and CEO of London-based startup, UNDO, enhanced rock weathering (EWR) is the fastest-scaling carbon dioxide removal (CDR) technology. He first came across the concept of ERW – which escalates the geologically slow process of rock carbon sequestration — in February 2020.
At the time, as he wrote in a recent blog post, EWR “was purely academic with significant lab results and exciting papers in Nature, but without commercial application of note.”
Three years later, his company has secured $12 million in funding from leading firms in the climate tech investment world: Lowercarbon Capital, AENU, as well as an additional contract renewal funding from Stripe, the owner of Frontier which is behind big tech’s newest $53 million CDR push. The renewal amounted to $1 million and follows a $500,000 purchase and research grant from Stripe in May 2021, inked alongside a contract to provide Microsoft with its first ERW project in April 2023.
“Enhanced rock weathering represents the rare CDR pathway where permanence, scalability, and co-benefits intersect,” Ferry Heilemann, founder and partner at AENU, said in a statement.
So, how does EWR work?
“Enhanced weathering is a natural process that we’re speeding up,” the startup’s research lead Mel Murphy said in the video below. “Weathering takes place over geological time scales, and what we’re doing is spreading crushed rock onto agricultural fields or onto forests.”
According to Ben Westcott, head of enhanced weathering at UNDO, what happens next is “Once it's on the land it reacts with the carbon dioxide which is dissolved into the soil waters and it effectively locks that carbon dioxide out of the carbon cycle permanently.”
There are a handful of different ways to do ERW. Over at the FootPrint Coalition Science Engine, one project uses protein geoengineering to accelerate the weathering of the mineral silicate and another is a part of the early-stage startup InPlanet, which enables farmers to practice lower-carbon agricultural practices and use natural rock powders from local mines for carbon capture instead of limestone, synthetic fertilizers, and pesticides.
Others like San Francisco-based startup, Heirloom Carbon, take that limestone, superheat it to release carbon dioxide, and then captures it, using the leftover minerals to capture MORE CO2 from the air.
Another cool ERW startup, 44.01, which last year won Prince William’s Earthshot prize, mineralizes CO2 in peridotite, an olive-toned rock found across the world, most predominantly in Oman, and buries it permanently underground.
UNDO takes a different approach — using volcanic rock dust from crushed basalt, a natural byproduct of mining and quarrying operations.
Like InPlanet’s strategy, UNDO says spreading the basalt dust across agricultural fields increases crop yield because as the rock breaks down, it releases nutrients such as magnesium, calcium, potassium, and phosphorus. This raises and stabilizes the soil pH and reduces the need for planet-harming fertilizers.
Initially piloted in Scotland, UNDO now has 17 sites across the United States and the United Kingdom, partnering with local agricultural communities and 50 landowners and farmers to scale the natural carbon-sequestration ability of cropland.
Last year, their operations resulted in 6,750 tonnes of CO2 locked away, and according to Mann, this year they are on track to 185,000 tonnes of basalt across 9,250 hectares, removing approximately 46,250 tonnes of CO2.
The money will help UNDO advance closer to its goal of removing one million tonnes of CO2 by 2025 and cutting down costs from $200 a tonne, which is a little more than a U.S. ton.
For context, thanks to tax incentives in the U.S. operators using carbon capture, can currently do so for about $85 a ton. This type of carbon capture is being deployed to offset that released from fossil fuel operations, so a more comparable number would be the $180 in incentives paid for direct air capture (DAC) which permanently stores CO2 already in the air.
However, unlike DAC, ERW projects work in direct environments, so according to Mann, “the biggest challenge we face is measuring and quantifying how many tonnes of CO2 have been removed.”
Still, UNDO’s one million mark would be huge. It only puts a tiny dent in the amount the IPCC says must be stored to avoid the worst effects of climate change, but they only represent one of the dozens of startups emerging in the CDR space.
One million tonnes captured would be equal to taking about 222,500 gas-guzzling cars off the road for a year, shutting down two and a half fossil fuel plants for a year, or the amount sequestered by over one million acres of U.S. forests.
According to the startup, this is the first step toward the billion-ton level operations it dreams of undoing human emissions' damage.
“This investment marks a significant milestone for UNDO and brings our mission to create a more sustainable future into full view. I’m grateful for the support of our investors and partners, and committed to developing scalable nature-enabled carbon removal that will have a lasting impact on our planet,” Mann said in a statement.
“The climate can’t wait — neither can we.”