What is Enhanced Rock Weathering?

Basalt is a mineral-rich volcanic rock that forms when molten lava cools. It’s highly reactive and weathers over the course of 20 years. It’s also one of the most abundant rocks on Earth, enabling us to scale our operations considerably.

Wollastonite has great carbon capture potential and weathers quickly relative to other silicate rocks. It also has a host of co-benefits for farming communities.

Spreading 1.6 tonnes of wollastonite has the potential to sequester 1 tonne of CO₂, whereas basalt takes 4 tonnes spread to sequester 1 tonne of CO₂. After spreading wollastonite on agricultural land, it only takes 12 months for 50% of the spread volume to weather. This means that 50% of the wollastonite’s carbon capture potential is achieved only 1 year after the spreading event.

Wollastonite, like basalt, is a silicate rock that contains much-needed nutrients for our soils. These include calcium (Ca²⁺), magnesium (Mg²⁺), and potassium (K+). When weathering takes place, these are absorbed into soils which can in turn result in higher crop yield, more pest-resistant plants, and stabilised soil pHs.

Both are safe to use and can significantly improve the health of the soil it’s spread on.

Our basalt is an existing product of aggregate and mining industries, so we aren’t using any additional energy to procure it. By spreading it locally using existing farm machinery, our operations have a 95% carbon efficiency.

Our wollastonite is mined and crushed to order. As wollastonite weathers and captures carbon incredibly quickly, the process has a 90% carbon efficiency.

Any emissions associated with the haulage of both silicate rocks are carefully measured with GPS monitoring and excluded from credits generated.

We believe all carbon removal solutions have a part to play in reversing the climate crisis. However, not all carbon removal technologies offer the same permanence, scalability and co-benefits as ERW.

Projects such as reforestation, while incredibly important for biodiversity, are not permanent. With tree planting, carbon is only locked up for the lifetime of the tree. Wildfires, tree felling and disease also increase the risk of reversal. In comparison, ERW locks carbon dioxide away for 100,000+ years.

Engineered solutions such as direct air capture (DAC) use machinery to capture CO₂ directly from the ambient air. This technology offers high durability, but large amounts of energy are required to build the new machinery and then operate the fans. Another key limitation of DAC is that there are very few co-benefits.

ERW offers the best of both worlds as we are accelerating natural solutions with added co-benefits while offering tech-based permanence.