Three Environmental Problems and One Solution—Or Is It Not Enough

An ambitious study in Illinois testing Enhanced Rock Weathering (ERW) as a solution to three global crises.

Rising Atmospheric CO₂: A Growing Threat to Our Planet

Ocean Acidification: The Hidden Crisis in Our Seas

Food Shortages: A Looming Challenge for Global Sustainability

Scientists are exploring a simple way to fight climate change—spreading crushed volcanic rock on farmland. In Illinois, fields treated with basalt dust absorbed 10 more metric tons of CO₂ per hectare and increased crop yields by 12-16% over four years. Other studies showed similar benefits.

This process, called Enhanced Rock Weathering (ERW), speeds up natural CO₂ absorption and stores it in the ocean. Unlike expensive carbon capture technologies, ERW is low-cost and easy to scale. Expanding globally could remove up to two billion metric tons of CO₂ annually.

However, challenges remain. Mining and transporting basalt produce emissions, and not all soils react the same way. Ethical concerns also surround labor conditions in the quarrying industry. Despite these risks, companies are already selling carbon credits for ERW. It could help farmers boost income while reducing atmospheric CO₂ if done right.

Positives of Enhanced Rock Weathering (ERW):

1. Carbon Removal: ERW can capture up to 2 billion metric tons of CO₂ annually, helping slow climate change.
2. Improved Crop Yields: Trials show a 12-16% increase in corn and soy yields, with some crops like biofuels improving by up to 42%.
3. Soil Health Benefits: Basalt replenishes essential nutrients (calcium, magnesium, silicon) and reduces soil acidity, leading to healthier crops.
4. Long-Term CO₂ Storage: The CO₂ absorbed becomes bicarbonate in water, storing it in oceans for hundreds to thousands of years.
5. Low-Tech and Scalable: ERW uses natural processes and existing farming infrastructure, unlike expensive carbon capture machines.

Negatives of Enhanced Rock Weathering (ERW):

1. Mining and Transport Emissions: Extracting, crushing, and transporting basalt releases CO₂, offsetting some benefits.
2. Uneven Effectiveness: ERW works well in some soils (e.g., Illinois) but underperforms in acidic or clay-rich soils (e.g., Australia, Malaysia).
3. Labor and Ethical Concerns: Mining industries in some countries have poor labor conditions, including bonded labor and health risks.
4. High Material Demand: To reach meaningful carbon removal, ERW would require billions of tons of basalt annually—scaling up may be difficult.
5. Risk of Overhyped Carbon Credits: If ERW is rushed or poorly implemented, it could lead to ineffective carbon credit markets, damaging trust in climate solutions.

https://www.scientificamerican.com/article/could-seeding-farm-fields-with-crushed-rock-slow-climate-change/