What is Enhanced Rock Weathering?

Enhanced rock weathering (ERW) is a nature-based carbon removal technology that accelerates the natural geological process of rock weathering to permanently remove CO₂ from the atmosphere. 

Rock weathering refers to the mechanical, chemical, and biological processes that break down rocks into smaller particles. These processes occur through exposure to wind, water, ice, and living organisms, causing the rocks to erode, fracture, and chemically degrade. UNDO leverages the natural chemical process when CO₂ combines with rainwater as it falls through the atmosphere. The rainwater interacts with rock formations it lands on and mineralises to form solid bicarbonate ions which are safely stored in the soil or washed out to sea.

In enhanced rock weathering, a much smaller and finer form of rock is used, meaning that a process that normally takes millions of years to break down a rock takes just decades instead. ERW comes with several environmental co-benefits, such as improving soil health, increasing crop yields and supporting rural communities with green jobs.