Green Sand Removes CO2 Without Harming Ocean Life

Scientists just proved that fighting climate change with green sand won't hurt the creatures living on the ocean floor.

In 2022, researchers scattered 650 tonnes of crushed olivine, a naturally green mineral, along a Long Island beach in New York. The tide carried the sand into the ocean, where it began absorbing carbon dioxide from the water.

The team feared the worst. Lab studies had shown that olivine's trace metals could poison crustaceans and molluscs. They worried the sand might smother worms, snails, and other bottom-dwellers that call the seafloor home.

But when researchers scooped up sediment samples before, during, and after the trial, they found something remarkable. Out of dozens of species studied, only one tiny worm declined in number. Within just two months, the overall abundance and diversity of ocean floor creatures bounced back completely.

Even better, the levels of nickel, chromium, and other metals in the organisms stayed safely low. The ocean's natural movement diluted any dissolving elements so quickly that marine life never accumulated dangerous amounts.

Here's how it works: Olivine naturally reacts with CO2 in water to form bicarbonate, a stable compound that locks carbon away for thousands of years. By adding crushed olivine to the ocean, the water can then absorb even more CO2 from the atmosphere. Recent research suggests spreading this mineral on farms and in oceans could remove up to 1.1 billion tonnes of CO2 every year.

The study's lead researcher, Emilia Jankowska at Hourglass Climate, says the results show olivine addition "might be ways that it could work and have a minimal effect" when carefully regulated. The UN climate body has said the world needs carbon removal methods like this to reach net zero emissions.

The Bright Side

This isn't just about one successful trial. It's proof that we can test climate solutions in the real world without harming nature in the process.

The researchers are already monitoring a larger trial off the coast of North Carolina, where 8,200 tonnes of olivine were deployed in 2024. Early results show species abundance and diversity recovered there too.

As global temperatures rise and extreme weather intensifies, solutions that work with nature instead of against it give us real hope for cooling our planet back down.