Rock On: How Crushed Stone Could Help Fight Climate Change

• Crushed stone is being used globally to combat climate change.
• Enhanced Rock Weathering speeds up the natural capture of carbon dioxide.
• ERW shows promise but remains a new technology in the field.
• Research shows variable success in carbon removal rates with ERW.
• ERW projects are being initiated worldwide, from Brazil to India.

Enhanced Rock Weathering: A New Climate Solution

Crushed stone is gaining attention globally as an innovative solution for fighting climate change, showcasing its potential from Brazil’s sugar plantations to India’s tea estates. In particular, the concept of Enhanced Rock Weathering (ERW) captures carbon dioxide—a significant greenhouse gas—and speeds up how natural processes can store this gas. With tech companies, airlines, and even quick-fashion brands eager to buy carbon credits from ERW projects to offset their own emissions, there is a newfound interest in how crushed rock could redefine climate action.

Effectiveness and Challenges of ERW Technology

ERW leverages a geological process known as weathering, where rocks are naturally broken down through reactions with carbonic acid. This acid forms when carbon dioxide dissolves into rain and interacts with rock, leading to a reduction in atmospheric carbon. While conventional weathering is a slow process, ERW aims to expedite it by utilizing finely ground, quick-weathering rocks like basalt. A US study estimated that applying 50 tons of basalt per hectare per year could remove up to 10.5 tons of carbon dioxide over four years, although some field trials have shown less efficacy in terms of carbon capture rates, partly due to variables such as local climate conditions and soil types.

Benefits, Risks, and Global Implementation

Interestingly, while these limestone-producing properties can contribute to enhanced crop growth and improved soil conditions, concerns linger regarding the risks associated with it. Although ERW is considered a safe method of accelerating natural processes, some quick-weathering rocks may have heavy metals, which raises health concerns when ground and applied to fields. Furthermore, as companies begin to sell carbon credits generated from ERW, there exist significant risks if the actual carbon capture falls short of expectations. Miscalculations could lead to a situation where emissions increase rather than decrease, casting doubt over the credibility of such environmental initiatives.

In summary, Enhanced Rock Weathering presents an innovative approach to mitigating climate change by utilizing crushed stone to enhance carbon storage in soil. However, while the technique has potential benefits for agriculture and the environment, its effectiveness and risks must be thoroughly assessed. As interest from industries grows, the accuracy of carbon capture measurements will play a crucial role in ensuring the credibility of ERW projects in the fight against climate change.