Our Technology
Climate Glossary
" />What is Enhanced Rock Weathering?
Enhanced rock weathering (ERW) is a nature-based carbon dioxide removal technology that permanently locks away CO2.This approach accelerates a natural geological process that has been happening for millions of years.
tonnes of rock
Acres spread
farms enriched
tonnes of CO2 to be removed
Understanding Enhanced Rock Weathering
Press play to watch a short overview of ERW, how it fits existing farming operations to capture CO2, and the co-benefits for agricultural communities.
The Enhanced Rock Weathering Process
We work with silicate-rich feedstock selected for chemistry, reactivity, and safety for agricultural use.
Rock is processed to the right particle size to support effective weathering, then screened and delivered through established logistics networks.
Local contractors and partners spread the rock using standard liming equipment, aligned with farm operations and seasons.
As the rock weathers, CO2 is converted into stable carbon, mainly dissolved bicarbonate that can be stored for thousands of years.
We rigorously track projects and collect both field and lab data to quantify carbon removal over time, supporting independent verification.
Our climate technology takes a holistic approach, with co-benefits that make our planet a happier, healthier place.
Soil Fertility
Silicate rocks, such as basalt and wollastonite, are mineral-rich. As they weather, they release nutrients such as magnesium, calcium, and potassium, improving soil health and pH.
Crop yield
Trials with the University of Newcastle show an increase in crop yield following the application of crushed basalt rock, supporting global food security.
Green Jobs
Our silicate rock is supplied and spread free of charge, reducing input costs for rural agricultural communities. Rather than importing machines and talent, we work with local contractors.
Ocean Health
The bicarbonate ions captured during the weathering process are eventually washed out to sea, where they help deacidify our oceans and are used by marine creatures to build their shells.
Choosing The Right Rock
Not all rock is suitable for enhanced rock weathering. We focus on silicate-rich feedstocks because their chemistry supports weathering reactions that permanently remove CO2.
To be practical at scale, a suitable material also needs to be available in large volumes, compatible with farm spreading, and deliverable through existing quarry and logistics networks.
Before any deployment, we assess suitability through material characterisation and quality checks, looking at key properties like mineral composition, reactivity, particle size, and contaminants.
Delivering ERW at Scale
Our mission is to permanently remove over a billion tonnes of CO2 and make carbon removal accessible to all. Reaching that scale depends on reliable supply chains, practical field delivery, and a measurement approach that holds up to scrutiny. That is what UNDO is built to do, across regions and partners.
We build regional supply chains for suitable silicate-rich materials, prioritising consistency, availability, and agricultural suitability. We work with established producers and logistics networks to support dependable delivery.
ERW is delivered using existing agricultural equipment, local contractors, and proven logistics routes. UNDO sets the delivery approach and standards, and works with on-the-ground teams to plan around farm schedules and field conditions to keep disruption low.
Participation is designed to be straightforward for farmers and to fit around normal farm operations. UNDO takes care of soil sampling, haulage, and spreading while the farmer enjoys the agronomic benefits.
Each deployment is tracked and documented to create a clear audit trail from material to field. This supports robust carbon accounting and helps enable independent verification over time.
Our Science, Technology, and Partnerships
Delivering ERW depends on three things: strong field science, traceable data, and delivery partners who can operate reliably at scale.
Our Science
From field trials to monitoring sites and lab work, our MRV programme is built to measure weathering in real conditions. We collaborate with academic research partners to strengthen methods and deepen understanding.
Our Partnerships
ERW only scales through strong relationships on the ground. We work with farmers, contractors, suppliers, labs, and research partners to deliver consistently across communities and regions.
Measurement and Verification
Credible carbon removal depends on geochemical evidence. ERW is quantified by combining rock characterisation, field activity data, and environmental measurements that indicate weathering.
We also include operational emissions inputs so we can report net carbon removal over time, using conservative methods designed to support independent verification as standards evolve.
Enhanced Rock Weathering in Action
From first-of-a-kind agreements to field operations, showcasing the work behind scaling enhanced rock weathering.
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FAQs
ERW is a carbon dioxide removal approach that accelerates the natural process of rock weathering. Finely crushed silicate rock is applied to land, where it reacts with CO2 in rain and soil water as it breaks down. This converts CO2 into stable carbon in water and minerals over time, delivering durable carbon removal.
Carbon removal is quantified by combining field activity data with scientific measurements and conservative accounting. This includes characterising the material applied, tracking where and when it is spread, and using environmental measurements that indicate weathering in real conditions. Operational emissions are also accounted for, so results are reported as net removal. Reporting is designed to be audit-ready and to support independent verification, with methods and uncertainty handled conservatively.
The LCA covers emissions associated with delivering ERW, so we can report net carbon removal. This typically includes material sourcing and processing, transport, field application, and other operational activities required to deliver a project. Those emissions are deducted from the gross CO2 removed through weathering to calculate net removal.
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 the credits generated.
ERW uses natural silicate rock applied to farmland using standard agricultural practices and equipment. Before deployment, material suitability is carefully assessed, including checks to ensure no potentially toxic elements (PTEs). In Ontario, Canadian Wollastonite’s crushed rock is accredited for use in organic farming by OMRI, approved by the Canadian Food Inspection Agency for use as a fertilizer, and PTEs are monitored against CFIA T-4-93 safety standards to help ensure they remain within acceptable limits for soil and groundwater. UNDO also works with local water authorities and carries out environmental assessments as part of its operational approach.
Weathering happens over time, not all at once. Reaction rates depend on local conditions such as rainfall, soil chemistry, temperature, and the properties of the material applied. Carbon is captured mainly as dissolved bicarbonate and other stable carbon forms that can persist for very long periods, typically tens of thousands of years or more in the ocean system, which is why ERW is considered highly durable or permanent.
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