olivine sand – A one-year ocean trial adding crushed olivine to absorb atmospheric CO2 found no adverse effects on the seafloor ecosystem, though researchers warn that the monitoring may not have captured all risks.
When Vesta deposited 650 tonnes of olivine sand along a beach in Long Island, New York, in 2022, it was an attempt to pull carbon out of the air by nudging the ocean chemistry. A year later, researchers looking at the seafloor say they did not find clear harm to marine life.
The trial. designed to test whether crushed olivine can react with dissolved CO2 to form bicarbonate and lock it away for thousands of years. is the first of its kind.. Researchers scooped up sediment from the shallows before the addition. immediately after. and again a year later—comparing sites exposed to olivine with nearby areas that received only regular sand or no added sand.
For decades, the climate math has been tightening.. The United Nations climate body has said the world will need carbon removal methods—ranging from planting trees to filtering CO2 from the air with giant machines—to reach net-zero.. As global warming targets slip further out of reach. companies and researchers are betting that mineral-based approaches could help cool the planet back down.
In this New York test, the biological signal was complicated but not alarming.. Of dozens of species examined, only a tiny worm called the fringed blood worm significantly declined in the olivine area.. Overall abundance and diversity among bottom-dwelling species recovered within two months.. Species composition shifted. but it also changed in the section where only normal sand was added—suggesting that the beach nourishment itself. not the green sand. may have been responsible for part of the shake-up.
Most importantly for critics who worry about contaminants, concentrations of nickel, chromium cobalt and manganese in organisms stayed low.. Emilia Jankowska. who led the study at the non-profit Hourglass Climate. said the natural system diluted any dissolving constituents quickly: “The natural system is just so dynamic that any dissolving constituents are very rapidly diluted.”
Still, the reassurance has limits.. Researchers warn that a year of data may not be enough to reveal slower or subtler damage.. The study itself notes that the results may not have captured all potential negative impacts—and Jankowska stresses that olivine should still be carefully regulated. with room for approaches that “could work and have a minimal effect.”
The concern begins with what olivine can contain.. Olivine. a greenish magnesium iron silicate common in Earth’s mantle. tends to react with CO2 dissolved in rainwater and eventually feeds stable compounds into the ocean.. But lab studies have found elevated levels of nickel and chromium in crustaceans and molluscs exposed to it.. There is also worry that the material could smother bottom-dwellers, including crustaceans, molluscs, snails and worms.
Even among supporters, real-world complexity matters.. Christopher Pearce at the National Oceanography Centre in the UK said dissolving olivine can encourage calcium carbonate to precipitate out of seawater. helping lock away trace metals.. That process, he cautioned, can also reduce how much additional CO2 the seawater can absorb.. Pearce called the study a necessary bridge: “It’s a really critical study to move from lab-based understanding to real-world interactions. ” adding that further trials will be important for understanding different biological responses and different rates of CO2 uptake.
But opponents argue the “no adverse effects” headline may be overstated by the trial’s exposure pattern.. James Kerry of OceanCare said the evidence points to a different uncertainty.. He noted that fluctuations in olivine concentration—linked to what the study described as “burial–re-exposure cycles”—meant the particles might have been buried for much of the time under a far larger volume of normal sand deposited during beach works.. “The lack of accumulation that’s apparent may reflect limited exposure. not necessarily that the material is intrinsically safe. ” Kerry said.
The monitoring adds another layer of scrutiny. Vesta carried out the environmental monitoring, and Jankowska and Hourglass’s founder previously worked for the company. To independently assess the monitoring data, Hourglass received philanthropic funding from the Grantham Foundation.
Looking ahead, the next test is already underway.. Hourglass says it is now monitoring impacts from a larger Vesta operation in which 8. 200 tonnes of olivine were sunk 450 metres off Duck. North Carolina. in 2024.. Jankowska reported that preliminary results suggest species abundance and diversity recovered.. Hourglass is still analysing metal accumulation.
olivine CO2 removal ocean carbon removal mineral carbonation bicarbonate seafloor ecosystem marine life nickel chromium beach nourishment Vesta Hourglass Climate Grantham Foundation Duck North Carolina
So basically they threw rocks in the ocean and it was fine? Cool story.
I don’t buy it. “No adverse effects” is what they say until it’s too late. Also why does it matter if a worm died, that’s still something living.
They compared the olivine area to normal sand and even said the beach nourishment might’ve messed with the ecosystem more than the green sand. So like… how do you even blame the rocks then? Feels like they didn’t actually isolate the cause.
Nickel/chromium/cobalt in the article is what stuck out to me. Like, if it’s absorbing CO2 but also could add metals, that’s not exactly comforting. “Monitoring may not have captured all risks” is also scientist-speak for we don’t know, which is kinda scary in the ocean.