Fast-tracking a natural climate solution by compressing millennia of carbon capture into hours
Researchers have managed to speed up a natural process that normally takes thousands of years, creating a lab “machine” to capture carbon dioxide. A new study shows how limestone, dolomite, and seawater can be used as a natural carbon absorption system and could help reduce emissions from power plants in the future. By running CO₂ and seawater through columns filled with these common rocks, the team demonstrated a controllable way to lock carbon safely in dissolved form, rather than letting it escape into the air. The system already works but currently captures only part of the CO₂, leaving clear room – and a clear roadmap – for engineering improvements toward a practical, nature-based carbon capture technology.
What if it were possible to take a very slow geological process, one that takes thousands of years in nature, and speed it up so that it happens within hours, in order to slow the rate of global warming?
That is exactly what Noga Moran, Dr. Yonaton Goldsmith from Hebrew University and Dr. Eyal Wargaft from the Israeli Open University did in a new study published in Environmental Science & Technology, a leading journal of the American Chemical Society.
The increase in the amount of carbon dioxide in the atmosphere causes global warming and climate change. The new study suggests a method for preventing the release of carbon dioxide from power plants that could help reduce warming.
Brief background: What happens in nature?
In nature, carbon dioxide dissolves in rainwater, forming a slightly acidic solution. This water seeps through limestone and dolomite rocks, reacts with them, and forms bicarbonate ions, a dissolved form of carbon, that are carried by rivers to the oceans.
This process is one of the main mechanisms by which the Earth removes carbon dioxide from the atmosphere. However, it occurs at a very slow rate and is limited by the availability of water, carbon dioxide, and the surface area of the rock. On its own, it is far too slow to significantly reduce the intensity of global warming.
The current study investigates how this process can be made to happen faster and in a controlled manner, inside a reactor that mimics natural conditions.
What did the researchers discover?
In this new study, the researchers built a tall, transparent reactor filled with limestone and dolomite and flowed seawater and carbon dioxide through it. In this way, they were able to “compress” a very slow natural process, carbonate weathering, into a controlled experiment.
The study shows how this process can be made to work efficiently in a reactor. Among other things, the researchers:
- Identified an optimal CO₂-to-seawater ratio at which the system uses carbon dioxide most efficiently.
- Found that gentle recycling of the gas improves the reaction, while too much circulation actually reduces efficiency.
- Showed that grain size matters: smaller grains lead to more total carbon dissolved, while larger grains create smoother pathways that speed up the reaction rate.
- Demonstrated that dolomite may be a better rock for carbon capture because it does not produce secondary carbonate precipitates that could release carbon back into the atmosphere.
- Measured the system’s overall efficiency: currently only about 20% of the introduced CO₂ is converted into dissolved carbon, suggesting that engineering improvements could significantly enhance performance.
Together, these findings map out the practical conditions under which a natural carbon capture process can be replicated in the laboratory and turned into an engineering basis for developing future systems to reduce emissions in power plants and industry.
“The goal was to understand what’s really happening when carbonate rocks encounter high levels of carbon dioxide. Once we figured out the conditions that allowed the process to work efficiently, we could see how something natural and slow becomes a controlled process that can be measured and tuned,” says Noga Moran.
In memory of Dr. Eyal Wargaft
The study is dedicated to Dr. Eyal Wargaft, the initiator of the research and a lecturer at the Open University, who passed away from cancer during the study.
“Eyal was a brilliant scientist and a great teacher,” says Moran. “He believed that science was part of the solution to the climate crisis, and this work bears his fingerprint at every stage.”
Journal
Environmental Science & Technology
Method of Research
Experimental study
Subject of Research
Not applicable
Article Title
Maximizing Carbonate Weathering Rates in an Open-System Benchtop Reactor as a Means of CO2 Capture
Article Publication Date
8-Dec-2025
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