Enhanced rock weathering is a technique that involves spreading crushed volcanic rock powder on cropland to remove excess carbon dioxide from the atmosphere. The process takes advantage of Earth’s natural carbon cycle, trapping atmospheric CO2 in the rock and then releasing it as stable bicarbonate into the ocean, where it can be utilized by marine life. This method has gained attention as a potential solution to climate change by removing carbon dioxide from the air and helping to moderate Earth’s temperatures over time.
Research on enhanced rock weathering has shown promising results, with computer simulations suggesting that the method could remove up to 215 billion tons of CO2 over the next 75 years if applied globally. By accelerating the natural weathering process, enhanced rock weathering could significantly contribute to meeting climate goals set by the Intergovernmental Panel on Climate Change. Proponents argue that this method offers multiple benefits compared to other carbon dioxide removal technologies, such as lower energy requirements, complementary land use, and potential soil health improvements for farmers.
Despite its potential benefits, enhanced rock weathering faces challenges and uncertainties. One major concern is the accumulation of heavy metals in soils from repeated applications of rock powder. The long-term environmental impacts of heavy metal contamination and the effects on soil microbes are not fully understood. Measurements and verification of carbon removal in this process have also raised issues, as current methods rely on simulations and field measurements that may not accurately capture the complexity of nature.
To address these concerns, companies are working on developing standardized measurement methods and certification standards for enhanced rock weathering. Programs like Puro.earth are aiming to ensure that carbon credits from this method are generated and verified accurately. Some start-ups have already adopted these verification processes and successfully sold carbon credits based on enhanced rock weathering. Government funding for this technology has also begun to shift towards supporting and scaling up the technology, with projects receiving grants to further develop and implement enhanced rock weathering on a larger scale.
Moving forward, research on enhanced rock weathering continues to expand, with potential for combining this method with other carbon removal strategies and nature-based solutions. The goal is to achieve climate goals by 2030 and avoid the worst effects of climate change. Collaboration, innovation, and openness to all climate solutions are essential in the fight against climate change. This all-hands-on-deck approach may be crucial to reaching net-zero emissions and mitigating environmental impacts for future generations.
