Scientists from UC Davis and Cornell University have made a groundbreaking discovery regarding carbon storage in soil. Their research reveals that applying crushed volcanic rock to croplands can effectively store carbon, even in drought-prone regions like California. This technique, known as “enhanced rock weathering,” has the potential to capture up to 215 billion tons of CO2 over the span of 75 years if implemented globally. The findings are particularly significant as they suggest that this method could be successful in drylands, which currently cover 41% of Earth’s surface and are expanding due to climate change.
The study conducted by researchers from the University of California, Davis, and Cornell University involved a field test in which crushed volcanic rock was applied to a fallowed cornfield in the Sacramento Valley. The measurements were taken during the winter months of 2020 and 2021, which coincided with an extreme drought in California. Despite the challenging conditions, the study found that the plots with crushed rock stored 0.15 tons of carbon dioxide per hectare, outperforming the plots without crushed rock. This amount of carbon removal across all croplands in California would be equivalent to taking 350,000 cars off the road annually.
The process of rock weathering involves the reaction between rain-captured carbon dioxide and volcanic rock, which naturally locks up carbon over millions of years. By crushing the rock into a fine dust, the process of rock weathering is expedited. Previous estimates have suggested that this enhanced rock weathering technique could store an impressive 215 billion tons of carbon dioxide if implemented globally.
However, until now, the technology had not been tested in dry climates. The success of this field test in California’s drought-prone region is a significant breakthrough. Lead author Iris Holzer, a doctoral candidate at UC Davis, emphasized the importance of testing the technology in drier climates due to the global carbon storage potential of enhanced weathering.
Additionally, the researchers highlighted the relevance of investigating enhanced rock weathering in drylands, as they represent a significant portion of Earth’s land surface, which is expanding due to climate change. Forty-one percent of Earth’s land is currently covered by drylands, making it increasingly important to explore sustainable solutions for carbon removal in these areas.
While the results of this study are promising, the researchers acknowledge that scaling up the technology and measuring carbon storage on a larger scale over time will be the next challenge. However, they remain optimistic about the potential of “enhanced rock weathering” to contribute to the global effort of carbon dioxide removal and mitigate climate change.
The findings of this research were published in the journal Environmental Research Communications. The study was funded by the California Strategic Growth Council and the Grantham Foundation, with support from the Working Lands Innovation Center. The crushed rock used in the experiment was donated by SGI, a Standard Industries company, from its site in Ione, California.
This groundbreaking research opens up new possibilities for carbon removal in agriculture, particularly in dry climates. As the world faces the urgent need to reduce greenhouse gas emissions and combat climate change, the potential of “enhanced rock weathering” offers hope for a sustainable future.