Understanding Enhanced Weathering

If you’ve read our previous piece on carbon removal, then you’re already familiar with the concept of enhanced weathering and its role in sequestering carbon dioxide (CO2). In this piece, we’ll go into a bit more detail regarding our enhanced weathering methodology and how we work with partners in the whole carbon removal value chain.

Enhanced weathering 101

You might remember hearing about rock weathering in geography classes at school; it’s a naturally occurring process that continuously erodes away rocks whilst storing atmospheric CO2.  It is a core part of the global carbon cycle, where CO2 dissolved in rainwater reacts with rocks and is locked away in carbonate form for hundreds of thousands of years. 

“Natural rock weathering slowly sequesters billions of tonnes of CO2 over hundreds of thousands of years. Enhanced weathering accelerates this process.”

At UNDO, we accelerate natural rock weathering by spreading crushed basalt onto the right soils in the right climates, permanently locking away CO2 in support of a net zero future. By using crushed rock, we can accelerate the weathering process and sequester CO2 hundreds of times faster. We focus on basalt because it has low levels of heavy metals and is safe for agricultural use.

Finely crushed basalt is an existing product of the quarrying industry that we spread onto farmland and forestry using standard agricultural equipment. Once spread, it begins to lock CO2 away immediately, much like a sugar cube dissolving in water. 

We find basalt rock all over the world, as it is routinely quarried for construction and road building, amongst other uses. Because the crushed rock is a product of an existing industry, we aren’t using additional energy to produce it and have established a robust process for accounting for any carbon footprint from our own operations.

Carbon removal with added benefits

To ensure the safety of all our operations, we conduct extensive testing of our rock to ensure that it is safe for agricultural use. In fact, by spreading crushed basalt on agricultural land, we’re adding significant benefits to the soil. The UNDO basalt rock is approved for organic use by the Soil Association and the farmers we work with get the nutrient benefit of the rock, helping them to maintain healthy soils. By supporting soil health, enhanced weathering can help our agricultural partners.

“Enhanced weathering helps support healthy soils and the communities that rely on them.”

Because of the way we transport and spread rock, our operations not only support farmers but also the rural communities of which they are a part. Whilst we must have a broad range of carbon dioxide removal technologies if we are to meet our net zero targets, enhanced weathering has the benefits that it does not require new infrastructure or installations, does not divert land away from food production and does not require significant additional energy. We design our operations for maximum sequestration, which means minimising additional processing and haulage.

A scientific approach to support our business model

We model the rate at which our crushed basalt rock breaks down and reacts with CO2 dissolved in soil waters. We then apply a buffer to that model to ensure that we are conservative in our predictions and conduct intensive monitoring in selected locations to guarantee the accuracy of our predictions. We then generate carbon credits based on the data collected during our operations, which we sell on the voluntary carbon market. Voluntary carbon markets allow carbon emitters, private investors, governments, non-governmental organisations, businesses and individuals alike to offset their unavoidable emissions by purchasing carbon credits. According to McKinsey, “voluntary carbon credits direct private financing to climate-action projects that would not otherwise get off the ground”.  

We work with partners who have credible net zero plans and strategies, and who are actively reducing emissions in all aspects of their businesses, so our carbon credits are used to offset their irreducible footprint.

“The combination of permanent carbon removal and co-benefits make enhanced weathering a powerful solution in the fight against climate change.”

Our partners value the CO2 we lock away through enhanced weathering for two main reasons. Firstly, because of the positive contribution the process makes to agriculture and rural economies. Secondly, because of the permanence of the process: once the reaction between CO2 and weathered rock takes place, it is very difficult to reverse. CO2 stays locked away for hundreds of thousands of years or, as far as humans are concerned, permanently. The combination of permanence and additional benefits is what makes enhanced weathering such a powerful solution in the fight against climate change.

Interested in becoming a carbon removal partner? Get in touch to find out how we can help you become a net-zero business.

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Ben Westcott

Chief Operating Officer

Ben is responsible for the planning and execution of our enhanced weathering operations. He led the first commercial enhanced weathering operations in the UK and has subsequently built out our partnership model and our global footprint.