Enhanced rock weathering (ERW) is an innovative process that accelerates a natural geological phenomenon to capture and store carbon. Over millions of years, silicate rocks like basalt naturally weather when exposed to CO₂ in rainwater, forming stable bicarbonates that are eventually stored in oceans.

ERW speeds up this process by finely crushing silicate rocks and spreading the powder over agricultural land, increasing the surface area to make the CO₂ capture happen much faster—on the scale of decades, rather than millennia.

This method not only captures carbon from the atmosphere but stores it in stable forms for over 100,000 years, making it one of the most durable carbon removal solutions available today.

ERW has significant scalability and global impact potential. Studies estimate that ERW could remove between 0.5 and 4 gigatons of CO₂ annually under optimal conditions, making it an essential solution in the race to achieve net-zero emissions globally.

Beyond carbon: The co-benefits of enhanced rock weathering

ERW offers much more than just carbon removal. It provides a range of co-benefits that support soil health, agricultural productivity, and even marine environments:

1. Soil health and fertility

When basalt rock is applied to soils, it enriches them with vital nutrients such as calcium and magnesium, improving soil fertility and pH balance. This leads to healthier soils that are more resilient to erosion and degradation. Research has shown that basalt amendments significantly boosted crop yields without introducing harmful chemicals into the soil.

2. Agricultural productivity

Farmers benefit directly from ERW through increased crop yields and reduced reliance on synthetic fertilisers. ERW acts as a natural fertiliser, improving soil quality and reducing input costs, allowing farmers to cultivate more sustainably.

3. Ocean health

The benefits of ERW extend to the oceans as well. By converting atmospheric CO₂ into alkalising bicarbonate ions, which eventually drain into the ocean via runoff, ERW helps combat ocean acidification – a growing concern for marine ecosystems such as coral reefs and shellfish populations. This dual benefit – helping both terrestrial and marine environments – makes ERW a holistic solution to climate change.

4. Economic opportunities

ERW projects create green jobs, particularly in rural areas. From quarrying operations to rock spreading on farmlands, these projects help stimulate local economies by leveraging existing agricultural infrastructure and machinery.

Meet the projects: ERW in action

Several forward-thinking companies are already implementing ERW on a large scale, proving its potential as a key carbon removal solution.

UNDO utilises basalt rock sourced from local quarries and spreads it across farmland, achieving 95% carbon efficiency. This innovative method is helping to reduce CO₂ emissions in agricultural systems and demonstrating the scalability of ERW.
InPlanet, operating in Brazil’s tropical regions, is leveraging ideal soil and climate conditions to accelerate weathering rates and remove carbon more efficiently. In 2023 alone, InPlanet spread 50,000 tons of rock powder, capturing 10,000 tons of CO₂—a testament to ERW’s scalability and effectiveness.
Veolia has teamed up with biotech company FabricNano to apply enzymes to basalt rock, speeding up the weathering process. This breakthrough trial is set to reduce the carbon removal timeline from decades to just a few years, potentially transforming ERW into an even more efficient solution for large-scale deployment globally.

These projects, along with many others, are shaping the future of ERW and demonstrating its powerful role in addressing climate change.

Scaling ERW for a net zero future

Enhanced rock weathering holds immense promise for the future of carbon removal. By accelerating the natural weathering process, ERW captures atmospheric CO₂ and stores it permanently, all while enriching soils, boosting agricultural productivity, and improving ocean health.

As more organizations scale their ERW operations, the world moves closer to realizing the full potential of this innovative carbon removal solution. With its scalable impact and multi-faceted benefits, ERW is poised to play a vital role in achieving global net-zero targets, one ton of CO₂ at a time.

To learn more about how ERW can help meet your carbon removal goals, reach out to Opna today at hi@opna.earth.