Enhanced Rock Weathering (ERW) – An Innovative Approach to Net Zero
- Sally Kim
- Oct 14, 2025
- 2 min read
As global temperatures continue to rise and climate targets slip further out of reach, scientists are urgently exploring new ways to remove carbon dioxide (CO₂) from the atmosphere. While most attention is diverted to renewable energy or electric vehicles, an overlooked, more natural solution is gaining momentum—enhanced rock weathering, a method that can turn ordinary volcanic rock into a powerful carbon sponge.
The process is simple in theory: crush volcanic rocks such as basalt into fine dust and spread them over farmland. When rainwater and soil interact with this dust, a chemical reaction occurs, as the dust captures CO₂ and transforms it into stable minerals, locking the carbon away for thousands of years. Essentially, it speeds up a natural geological process that normally takes millions of years.
In Brazil’s Cerrado region, a startup business, Terradot, is already testing this idea on a large scale. The company has spread around 100,000 tons of basalt across more than 4,500 hectares of farmland, aiming to remove an estimated 300,000 tons of CO₂ from the air. Contrary to what some might expect, enhanced rock weathering doesn’t degrade farmland but instead enhances its quality. Farmers involved in the project say they’ve also seen improvements in soil quality and crop yields, since basalt helps reduce acidity and restore nutrients.
Dr. Mariana Sousa, an environmental scientist at the University of São Paulo, explains that enhanced rock weathering could be scaled up globally as a carbon removal solution, since it works in harmony with farmland rather than against it.
However, not everyone is convinced of the strategy's effectiveness. The biggest challenge is verification—measuring exactly how much carbon has been permanently stored underground is complicated and costly. Effectiveness also varies depending on local conditions such as rainfall, soil chemistry, and temperature. Some experts warn that if these limits are ignored, enhanced rock weathering could be seen as a “greenwashing” tool rather than a genuine solution.
Still, this method represents an innovative shift in the global climate response. Instead of relying solely on futuristic machines or massive infrastructure, scientists are turning to the Earth itself for help. Perhaps, once improvements are made to measurement mechanisms, ERW may be the most promising solution to achieve net-zero.
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