Scientists say that ‘enhanced rock weathering’ could help to cool our overheating planet

As climate change gains global significance, the Intergovernmental Panel on Climate Change (IPCC) recently warned that the world is nearing the target of limiting warming to 1.5 degrees Celsius. The IPCC emphasized the need for feasible options to reduce greenhouse gas emissions and adapt to climate change caused by human activities.

According to a BBC report on Sunday (May 21), scientists at the United Nations (UN) agree that reducing greenhouse gas emissions alone would not be sufficient to prevent dangerous levels of warming. They suggest the necessity of carbon dioxide removal, actively extracting it from the atmosphere.

A process known as “enhanced rock weathering” has emerged as a potential solution to cool our warming planet. Enhanced rock weathering is a nature-based technology that permanently stores carbon dioxide (CO?) from the atmosphere. UNDO, a company specializing in enhanced rock weathering, explains that this natural process has occurred for millions of years, but they accelerate it.

Normally, carbon dioxide combines with rainwater to form carbonic acid, which interacts with rocks and soil, mineralizes, and safely stores carbon in carbonate form over hundreds of years. However, UNDO speeds up this process by spreading crushed basalt rock on farmland, increasing its surface area for immediate contact with CO? released by plant roots and soil microbes.

Enhanced rock weathering utilizes small pieces of rock to enhance the contact between rain and rock, leading to increased weathering and carbon removal. Basalt, the preferred rock, weathers slowly as a cliff or in quarries, but spreading it across a larger area maximizes carbon removal.

UNDO focuses on basalt rock due to its high reactivity and quick weathering, facilitating the sequestration of CO?. The company ensures that the process is safe and offers additional benefits for crop and soil health. In the coming year, UNDO plans to spread 185,000 tonnes of basalt and aims to remove one million tonnes of CO? by 2025.

However, experts express concerns that carbon removal techniques like enhanced rock weathering might divert attention from the priority of reducing emissions and could be used as a justification to continue carbon-intensive practices. Dr. Steve Smith, a carbon removal expert from Oxford University, warns that this idea may become a standard farming practice without addressing the root cause of emissions.