First test of CO2 removal with green sand finds no harm to marine life

A pioneering trial in Southampton, New York, tested the environmental impact of spreading olivine sand—a mineral known for its carbon dioxide (CO2) absorption properties—on a beach. The study, led by Emilia Jankowska of Hourglass Climate, found no significant harm to marine life following the addition of 650 tonnes of olivine sand atop 13,500 tonnes of regular sand used for beach nourishment. Researchers observed only a minor decline in one worm species, the fringed blood worm, but overall species abundance and diversity recovered within two months. Concentrations of potentially harmful metals such as nickel, chromium, cobalt, and manganese in marine organisms remained low throughout the trial. Olivine, a magnesium iron silicate, naturally reacts with CO2 dissolved in rainwater to form stable bicarbonate compounds that lock away carbon for thousands of years. This property has led to interest in using olivine to enhance natural carbon sequestration as part of broader efforts to mitigate climate change. The United Nations has emphasized the need for carbon removal technologies, including nature-based solutions and engineered approaches, to achieve net-zero emissions and limit global warming to 1.5°C above preindustrial levels. Vesta, a US start-up, is exploring the direct addition of olivine to oceans to accelerate CO2 uptake, but concerns have been raised about potential toxicity from trace heavy metals and physical impacts on bottom-dwelling marine species. The Southampton trial is the first field test of this ocean-based carbon removal method and provides encouraging evidence that olivine addition may have minimal short-term ecological effects when carefully managed. However, researchers caution that longer-term impacts and broader ecosystem responses require further study before large-scale deployment. The findings also highlight the need for regulatory oversight to balance climate benefits with marine environmental protection. As climate change intensifies and coastal ecosystems face increasing stress, innovative solutions like olivine spreading could become important tools in the global carbon removal portfolio, provided their risks are thoroughly understood and mitigated.