Scientists at the University of California, Davis, and Cornell University have made a groundbreaking discovery in the field of carbon sequestration. They have found that adding crushed volcanic rock to cropland can effectively store carbon in the soil, even in dry climates. This new method of carbon storage could have significant implications for combating climate change.
The process of rock weathering naturally captures carbon dioxide from the air and locks it up by reacting with volcanic rock. However, this process typically takes millions of years to occur. In order to speed up the process, the researchers crushed the rock into a fine dust. This “enhanced” rock weathering could potentially store 215 billion tons of carbon dioxide over the next 75 years if implemented across croplands globally, according to previous studies.
To test the effectiveness of this method, a field study was conducted in California’s Sacramento Valley during an extreme drought. The researchers found that the plots with crushed rock stored 0.15 tons of carbon dioxide per hectare, compared to plots without crushed rock. This amount of carbon storage, if replicated across all California cropland, could be equivalent to taking 350,000 cars off the road annually.
The researchers are optimistic that even infrequent heavy rains in dry regions could drive enhanced rock weathering and help remove carbon dioxide from the atmosphere. This is particularly important considering that drylands, which cover 41% of the Earth’s land surface, are expanding due to climate change. Investigating enhanced rock weathering in these areas is crucial for carbon removal efforts.
While this discovery is promising, the next challenge is to measure and verify carbon storage at larger scales and monitor it over time. This will ensure the effectiveness and sustainability of this method. The research was funded by the California Strategic Growth Council and the Grantham Foundation, with support from the Working Lands Innovation Center. Crushed metabasalt rock, necessary for the study, was generously donated by SGI, a Standard Industries company.
Overall, this study offers a ray of hope in the fight against climate change. The potential of enhanced rock weathering to store carbon in cropland, even in dry climates, is a significant breakthrough. Further research and implementation of this method could play a vital role in reducing greenhouse gas emissions and mitigating the effects of climate change.
