Researchers from the University of California, Davis and Cornell University have found that the use of pulverized volcanic rock on agricultural lands has the potential to store carbon in the soil, even in areas prone to drought such as California. This method, known as “accelerated rock weathering,” could sequester up to 215 billion tons of carbon dioxide over a period of 75 years if globally adopted. The effectiveness of this technique in arid regions points to its applicability in drylands, which constitute 41% of the Earth’s surface and are expanding due to climate change.
Field Experiments Confirm Soil Carbon Storage in Arid Regions
Utilizing crushed volcanic rock on agricultural fields has been identified as a significant means of carbon capture. In an empirical study, scientists from the University of California, Davis, and Cornell University verified that this approach effectively stored carbon in the soil even under the severe drought conditions that California was experiencing. These findings were published in the journal Environmental Research Communications.
Rainwater absorbs carbon dioxide as it descends and chemically reacts with the volcanic rock, effectively immobilizing carbon. Naturally, this rock weathering process could take millions of years, making it impractical for mitigating current rates of global warming. However, by grinding the rock into fine particles, the rate of rock weathering is substantially accelerated. Prior research has estimated that this accelerated form of rock weathering could sequester as much as 215 billion tons of carbon dioxide over the ensuing 75 years if implemented on agricultural lands worldwide.
Innovative Carbon Storage Techniques for California’s Drylands
For the study, researchers spread crushed forms of metabasalt and olivine rocks over 5 acres of unused cornfields in the Sacramento Valley. Data was collected during the winter of 2020-2021, a period when California was undergoing an extreme drought, with rainfall at only 41% of its historical average. The study concluded that the plots treated with crushed rock sequestered 0.15 tons of carbon dioxide per hectare during the study period. If applied across all of California’s agricultural lands, this could equate to removing 350,000 cars from the roads annually.
Implications and Future Research
Lead researcher Iris Holzer emphasized the importance of understanding the method’s effectiveness in arid climates. “The reaction mechanisms involved require water,” she noted. “Given our interest in assessing the global applicability of accelerated weathering for carbon storage, it’s crucial to determine its feasibility in drier climates and assess the efficacy of different measurement techniques. We were encouraged to see carbon removal in such conditions.”
With 41% of the Earth’s landmass consisting of drylands, which are expanding due to climate change, the relevance of investigating accelerated rock weathering in these regions is increasingly vital.
Benjamin Z. Houlton, the senior author of the study, stressed the urgency of the situation. “We are in a critical race against time to alter the trajectory of global carbon emissions,” he said. “Our study provides a novel method to validate carbon dioxide removal via accelerated rock weathering, marking a significant advancement for the global application of this technology on agricultural lands.”
The study was part of the Working Lands Innovation Center and received funding from the California Strategic Growth Council and the Grantham Foundation. Contributions of crushed metabasalt rock were made by aggregates and mining company SGI, a Standard Industries entity, from their location in Ione, California.
Reference: The study titled “Direct evidence for atmospheric carbon dioxide removal via enhanced weathering in cropland soil” was authored by Iris O Holzer, Mallika A Nocco, and Benjamin Z Houlton and was published on 18 October 2023 in Environmental Research Communications. DOI: 10.1088/2515-7620/acfd89. Other contributors include Mallika Nocco from the Department of Land, Air and Water Resources at UC Davis.
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Frequently Asked Questions (FAQs) about Accelerated Rock Weathering
What is the main finding of the research conducted by UC Davis and Cornell University?
The main finding is that the application of crushed volcanic rock to agricultural lands can effectively store carbon in the soil. This is particularly significant because it works even in areas that are prone to drought, such as California.
What is “accelerated rock weathering”?
Accelerated rock weathering refers to the process of speeding up the natural weathering of rocks to capture carbon dioxide from the atmosphere. This is achieved by grinding volcanic rock into fine particles and applying them to cropland. The technique could sequester up to 215 billion tons of carbon dioxide globally over 75 years if implemented widely.
How does this method work in arid or drought-prone regions?
The study found that even in arid conditions, like those experienced in California, the application of crushed volcanic rock to agricultural fields was effective in storing carbon in the soil. This suggests that the method could be applicable in drylands, which make up 41% of the Earth’s surface.
What is the potential impact of this method on a larger scale?
If this method were applied globally, it could capture up to 215 billion tons of carbon dioxide over a 75-year period. Specifically for California, if applied across all of its agricultural lands, the method could equate to removing 350,000 cars from the roads annually.
Who funded the research and contributed to it?
The research was part of the Working Lands Innovation Center and was funded by the California Strategic Growth Council and the Grantham Foundation. The aggregates and mining company SGI, a Standard Industries entity, donated the crushed metabasalt rock for the study.
What are the next steps for this research?
The next steps include measuring and verifying carbon storage at larger scales and over longer periods. Researchers are also interested in exploring the method’s applicability in other types of climates and soil conditions.
How was the study published?
The study was published in the journal Environmental Research Communications on October 18, 2023. The DOI for the study is 10.1088/2515-7620/acfd89.
More about Accelerated Rock Weathering
- Environmental Research Communications Journal
- University of California, Davis Research Publications
- Cornell University College of Agriculture and Life Sciences
- Working Lands Innovation Center
- California Strategic Growth Council
- Grantham Foundation for the Protection of the Environment
- Standard Industries Company Profile
- Intergovernmental Panel on Climate Change (IPCC) on Carbon Sequestration
7 comments
Brilliant! But, i wonder, how do farmers feel bout this? Will they be willing to change their practices to include volcanic rock?
Hats off to the researchers! Science giving us hope again. Now if only the policymakers would listen and act on it.
this is what we need, innovative solutions. But the challenge remains: how do we implement this on a global scale? the costs and logistics could be a hurdle.
Intriguing study, but I’m curious about other climates. The research focused on drylands but what about more humid areas? Does it work there too?
I’m skeptical. It sounds too good to be true. what are the long-term effects of adding volcanic rock to soil? Any impact on the crops?
Impressive, but let’s not forget the study was funded by Strategic Growth Council & Grantham Foundation. Always gotta look at who’s funding the research. Could be biased.
Wow, this is groundbreaking! Who would’ve thought that something as simple as crushed rock could have such an impact on climate change. Awesome work!