London-based UNDO, a climate tech startup spreading volcanic rock dust on farms to capture carbon in the soil, has secured $12m (£9.6m) in funding.
The investment includes £9.6m in new funding led by Lowercarbon Capital and AENU, while the startup secured an additional £800,000 renewal from carbon removal purchaser Stripe.
UNDO said it will use the injection of capital to scale up carbon removal through enhanced rock weathering (ERW) in Scotland.
ERW is the acceleration of natural rock weathering. When CO2 in rainwater interacts with silicate rocks – such as basalt – it mineralises and is safely stored as solid carbon for hundreds of thousands of years.
To speed up this natural geological process, UNDO spreads crushed basalt rock – a by-product of the mining and quarrying industry – across agricultural land.
As this mineral-rich volcanic rock breaks down, it releases magnesium, calcium, potassium, phosphorus and other nutrients, increasing crop yield, raising and stabilising soil pH and ultimately reducing the need for fertilisers.
ERW is seen as a promising option to remove carbon from the atmosphere, a key element of net-zero targets.
Jim Mann, co-founder and CEO at UNDO, said: “To achieve net zero emissions by 2050, we need to remove at least 10 gigatonnes of CO₂ from the atmosphere every year. Enhanced rock weathering is one of the most vital climate tech solutions available today because it is permanent, highly scalable, and provides a host of co-benefits.
“We’re proud to be backed by many of the world’s most respected investors and corporate partners whose support will enable us to spread enough rock by 2025 to remove 1m tonnes of CO2 at a highly competitive cost.”
In April 2023, UNDO became Microsoft’s first enhanced rock weathering supplier. As part of the agreement, UNDO will spread 25,000 tonnes of basalt rock on agricultural land in the UK, which will permanently remove approximately 5,000 tonnes of CO2 over the next 20 years.
Ferry Heilemann, founder and partner at AENU, said: “Enhanced rock weathering represents the rare CDR pathway where permanence, scalability, and co-benefits intersect.
“We believe that with their proven carbon removal track record and emphasis on developing a trusted MRV methodology, Jim and the team at UNDO have what it takes to move the needle on negative emissions.”