Reviewed by Lexie CornerJan 6 2025
Researchers from the University of Manchester and the University of Leeds have identified key mechanisms that sustain organic carbon in the ocean, a process that influences fossil fuel formation, the climate, and carbon cycles. Their findings were published in Nature Geoscience.
Organic carbon typically decomposes in most environments, yet vast amounts remain preserved in marine sediments—a long-standing scientific mystery.
Preserved organic carbon can eventually transform into gas or oil, acting as a carbon reservoir that prevents carbon dioxide, a major driver of climate change, from entering the atmosphere.
The researchers identified two previously underappreciated processes essential for maintaining organic carbon beneath the ocean floor:
- Sorption is the process by which minerals absorb carbon.
- Molecular transformation is the process by which smaller, reactive molecules change into larger, less reactive molecules.
This understanding could inform strategies to reduce ocean carbon emissions, offering potential tools in addressing climate change.
Understanding how and why carbon is stored in marine sediments is crucial if we are to harness or replicate these natural processes to combat climate change. Our findings shed light on mechanisms that were previously overlooked, offering new pathways for carbon management.
Dr. Peyman Babakhani, Lead Researcher and Lecturer, The University of Manchester
The research team developed a comprehensive model that incorporates a wider range of carbon preservation processes than previous models. These include molecular transformation (the formation of larger, less reactive molecules), sorption (carbon uptake by mineral surfaces), hydrolysis (the breakdown of carbon in water), and burial in sediments.
The scientists compared their model with data collected from ocean sediments. Their results showed that carbon preservation efficiency was nearly three times higher than estimates from earlier models.
They also found that their model provided more accurate estimates of the amount of organic carbon stored beneath the ocean, aligning more closely with observed field data. By integrating their model with artificial intelligence, they identified the processes most critical to carbon preservation.
It was amazing to see how the combination of a new numerical model, Monte Carlo, and artificial intelligence provided crucial insight into the preservation of organic matter in marine sediments that had been debated for decades. AI, often seen as a black box, became a powerful tool when applied in the right way, helping us understand complex environmental processes.
Dr. Peyman Babakhani, Lead Researcher and Lecturer, The University of Manchester
The study highlights the critical role of molecular transformation and sorption in the carbon cycle. Together, these processes transport organic matter deeper into the ocean and protect it from degradation in the upper sediment layers.
This stored carbon can eventually transform into gas or oil, preventing its release into the atmosphere as carbon dioxide.
The findings and models could inform climate change mitigation strategies, including ocean fertilization.
Journal Reference:
Babakhani, P., et al. (2025) Preservation of organic carbon in marine sediments sustained by sorption and transformation processes. Nature Geoscience. doi.org/10.1038/s41561-024-01606-y.