The mineral that could remove 1 billion tonnes of CO2 from the atmosphere

And protect shorelines and oceans too- but will it go to scale?
Sade Agard
Ocean seafloor coral reef
Ocean seafloor coral reef

TOSHIHARU ARAKAWA/iStock 

  • Deploying crushed olivine in 0.1 percent-0.25 percent of global shelf seas, 1 billion tonnes of CO2 could be removed from the atmosphere.
  • The project's Coastal Carbon Capture™ approach could remove ocean acidity and provide shoreline resilience to rising sea levels.
  • If scaled up, the cost of carbon dioxide removal could be $35 a ton at the gigatonne scale.

Near the town of Southampton, NY, a team of scientists is hurrying along the coastline, salvaging coastal homes, habitats, and what is left of a navigable harbor — all with striking green sand in hand. While we hate to tell you that this obscure material has nothing to do with kryptonite, it sure does have a unique, eliminating power. This green sand is a highly reactive form of the crushed-up volcanic mineral known as olivine. And it can capture carbon dioxide.

Most Popular
message circleSHOW COMMENT (1)chevron

Project Vesta, a Public Benefit Corporation, spreads this crushed-up olivine sand along coastlines. The vision is to remove excess atmospheric carbon dioxide while nourishing Earth's oceans. "To have a healthy planet, we need healthy oceans - and we all rely on them for the oxygen we breathe. Coastal Carbon Capture™ removes ocean acidity, supporting ocean health - while harnessing the power of the oceans to safely and permanently remove CO2, which supports the whole planet," told CEO of Vesta Tom Green to IE.

Vesta explains that by spreading sand-sized grains of olivine across shorelines, the material interacts with the natural mechanical power of waves. Ultimately, this counteracts ocean acidification and improves the oceans' resilience to rising temperatures.

But how does Coastal Carbon Capture™ work? And why the striking green volcanic rock, olivine?

Accelerating Earth's billion-year-old natural CO2 removal

The mineral that could remove 1 billion tonnes of CO2 from the atmosphere
Aerial view of weathering cliff and ocean waves

iStock/ SaintM 

Coastal Carbon Capture™ (CCC) uses a form of enhanced weathering. In basic terms, it refers to the process of rock being broken into smaller pieces for Carbon Dioxide Removal (CDR). According to Vesta's website, Coastal Carbon Capture relies on Earth's long-term inorganic carbon cycle, a set of natural chemical reactions occurring for billions of years.

Essentially, by spreading large amounts of ground olivine-containing rock onto coastlines, it dissolves in seawater and triggers a reaction with carbonic acid- this form of carbon dioxide dissolved in seawater. The rate of CO2 absorption by the ocean is increased in this way, and so are the pH and alkalinity. In this way, ocean acidification can be counteracted.

So what happens when a magnesium silicate like olivine is not present?

Well, in the absence of a magnesium silicate, carbonic acid usually dissociates in a way that goes on to form hydrogen ions. This dissociation lowers the pH, creating more acidic conditions in oceans.

Vesta's Coastal Carbon Capture process speeds up a billion-year-old geological process into one relevant to human timescales. In doing so, it has the potential to help the global effort to reach net-zero carbon targets by 2030-2050. While enhanced weathering for carbon capture is not new, Coastal Carbon Capture (CCC) by dissolving olivine in seawater beyond the laboratory is a relatively untapped approach.

Vesta's Tom Green further reveals, "Olivine is one of the most abundant minerals on the planet and is the fastest weathering silicate. In olivine, the planet has given us a natural mineral which removes carbon dioxide pollution from the atmosphere."

This carbon chemical reaction is based on Earth's 'long-term inorganic carbon cycle,' which has been occurring for billions of years, keeping Earth's atmospheric CO2 concentrations in balance.

That is, of course, until humans began contributing billions of tons of emissions each year.

Grounded volcanic olivine for shoreline resistance

Vesta also aims to leverage its technology for coastal resilience. "With sea levels rising, the need for coastal protection has never been greater," shares Tom Green. "By working with the coastal protection industry, Vesta is well positioned to drive meaningful impact. Coastal communities around the world need sand, and Coastal Carbon Capture has the potential to help provide additional sand for coastal protection projects, turning them carbon negative and addressing both the symptoms and the root cause of the climate crisis."

While Vesta has yet to complete further testing before its technology can be scaled up and deployed globally, a pilot field study reveals potential. "The first CCC deployment was near the town of Southampton, NY. The town completed a dredging project to ensure their harbor stayed navigable and used the sand to remake their beach, protecting coastal homes and habitats. Carbon-removing olivine sand was added to the project, making it a carbon-negative beach. By adding olivine sand, the town was able to contribute to reducing local seawater acidity and carbon removal", shared Tom Green to IE.

The project has also caught the attention of Bill Gates. He tweeted: @mgrace_andrews of @Project_Vesta is using the natural mineral olivine and oceans to remove a trillion tons of carbon dioxide from the atmosphere. #WorldOceansDay pic.twitter.com/cGQaC9D6TC

A nature-based and permanent solution

By grinding olivine into sand-sized particles, Vesta aims to stimulate Earth's natural carbon cycle artificially. This way, the process may have a shot at being compatible with human timescales and the global emission targets that follow.

"Vesta is important because… as a society, we need 10 billion tonnes a year of carbon dioxide removal (CDR) by mid-century if we want to avoid the worst effects of the climate crisis. Coastal Carbon Capture™ (CCC) is a nature-based CDR method which has the potential, if scaled up, to remove carbon dioxide from the atmosphere for $35 a ton at gigatonne scale," says CEO of Vesta Tom Green to IE.

Dissolving olivine may also facilitate carbon uptake by marine organisms to produce their hard parts, such as shells and skeletons, building greater marine resilience. Once dead and buried in the sea bed, over millions of years, their remains eventually form limestone and provide a natural permanent solution for the storage of CO2.

From pilot to global scale

The mineral that could remove 1 billion tonnes of CO2 from the atmosphere
Mesocosms in the Dominican Republic for pilot projects

Project Vesta 

As intriguing as Coastal Carbon Capture may be, spreading large amounts of crushed olivine rock in ecologically delicate environments such as shorelines does come with challenges. According to this study, when olivine dissolves, naturally occurring metals such as nickel are released into seawater, which could pose a potential toxicity risk to marine life.

With this in mind, Vesta is collaborating with several institutions to carry out research on ecotoxicology to coral physiology to validate its technology further.

Furthermore, scientists have since deployed mesocosms in the Dominican Republic to examine dissolution rates. These small enclosed containers replicate the natural conditions of project sites where olivine could be potentially spread.

There are logistical challenges to consider, such as how to cost-effectively mine and grind minerals to the global scales Vesta hopes to achieve. Since olivine is 26% denser than quartz sand, carbon-efficient transportation mechanisms also need to be considered.

A millennia track record of olivine weathering- Papakolea Beach, Hawaii

The mineral that could remove 1 billion tonnes of CO2 from the atmosphere
'Olivine-weathering' green sand beach, Papakōlea, Hawaii

iStock/ Damien VERRIER

Naturally occurring olivine beaches that follow large-scale weathering exist — and Papakoleo Beach in Hawaii is an intriguing example. Olivine has been weathering here for thousands of years, making this site an ideal study area for an improved understanding of the process.

Adjacent to these beaches is non-olivine beaches, providing an ideal environment for comparing and assessing the possible ecotoxicological effects of Coastal Carbon Capture. According to the website, Vesta is currently collaborating with scientists at the University of Hawaii to examine risks by studying marine algae and small invertebrates from Papakōlea.

'Reversing the damage'

On an ending note, IE wanted to find out whether there were any misconceptions surrounding the technology that team Vesta would like to share. Tom Green revealed, "the media sometimes calls various forms of Carbon Dioxide Removal (CDR) geoengineering. Geoengineering means intentionally manipulating the climate, whereas CCC is an example of a nature-based Carbon Dioxide Removal process, which is about reversing the damage done to the climate by excess CO2 in the atmosphere."