Researchers testing a novel carbon removal approach in coastal New York found olivine, a green mineral, does not harm seafloor organisms when added to seawater. The pilot project marks the first direct assessment of this geoengineering technique's ecological safety.
Olivine absorbs carbon dioxide through a chemical reaction called weathering. When crushed and placed in seawater, the mineral dissolves slowly, converting dissolved CO2 into carbonate compounds that sink to the ocean floor. This process could theoretically remove gigatons of atmospheric carbon annually while raising ocean pH, counteracting acidification.
The experiment deployed olivine-filled containers on the seafloor near Ithaca, New York, monitoring surrounding benthic communities for two years. Researchers found no observable damage to bacteria, worms, mollusks, or other organisms living in the sediment. This result challenges concerns that adding minerals to marine environments could disrupt ecosystems through pH changes or smothering effects.
The work represents early-stage validation for ocean alkalinity enhancement, a technique gaining attention as nations seek scalable carbon removal methods beyond tree planting and direct air capture. Unlike some geoengineering proposals, olivine addition produces no toxic byproducts and uses naturally occurring minerals.
However, significant uncertainties remain. The pilot tested only a small area over a limited timeframe. Large-scale deployment would require assessing impacts across different ocean regions, depths, and seasons. Questions persist about whether seafloor ecosystems might experience delayed negative effects or whether alkalinity changes could alter fish behavior or nutrient cycling in ways the short study missed.
The research team documented baseline conditions thoroughly but acknowledged that scaling this approach would demand regulatory frameworks, cost analysis, and broader environmental monitoring. Olivine costs roughly $20 per ton, making deployment economically feasible compared to other carbon removal technologies, though transport and dispersal logistics add expenses