Enhanced rock weathering, a process that accelerates the natural weathering of rocks to remove carbon dioxide (CO2) from the atmosphere, could play a crucial role in combatting climate change, according to UN scientists.
As efforts to reduce greenhouse gas emissions alone may not be sufficient to prevent dangerous global warming, the need for carbon dioxide removal has become evident.
Jim Mann, the founder of UNDO, a company specializing in enhanced rock weathering, refers to the basalt rocks involved in the process as ‘magic dust.’ Basalt, a common volcanic rock, gradually removes carbon dioxide from the atmosphere through weathering.
However, enhanced rock weathering amplifies this process by increasing the surface area for interaction with rainwater, leading to more significant carbon removal.
In partnership with local farmers, UNDO spreads the leftover basalt rocks across fields. The process locks away carbon and enhances crop yields and grazing quality.
The basalt is dispersed by attaching a trailer filled with 20 tonnes of rocks to a tractor, which scatters them across the field.
UNDO estimates that one 20-tonne trailer load of basalt can absorb approximately 5 tonnes of CO2.
While some experts express concerns that carbon removal techniques might divert attention from reducing emissions, UNDO argues that both approaches are necessary.
The company plans to rapidly scale up operations, with Microsoft already supporting the initiative by financing the scattering of 25,000 tonnes of basalt on UK fields.
Despite the potential benefits, questions remain about the scalability of enhanced rock weathering. The energy and emissions associated with grinding, transporting, and scattering large quantities of basalt must be considered.
Nonetheless, experts believe the process could become standard for land use, delivering carbon removal benefits alongside other agricultural advantages.
UNDO aims to spread 185,000 tonnes of basalt this year and remove one million tonnes of CO2 by 2025.
However, this remains a fraction of the approximately 37 billion tonnes of CO2 discharged into the atmosphere in 2022.
Current atmospheric CO2 levels are the highest in at least two million years, underscoring the urgent need for effective climate change mitigation strategies.