“Enhanced weathering holds a great promise to solve the climate change problem, and it will restore the carbonate cycle in the oceans, threatened by the lowering of the pH, which may damage ocean life, in particular the healthy growth of coral reefs.”
Geochemist, Utrecht University
Olivine against climate change and ocean acidification (2011)
Project Vesta is a project to sequester carbon by accelerating the weathering of a specific type of rock called olivine. When olivine interacts with water and CO2, it creates a bicarbonate and alkaline solution that eventually sequesters the carbon as rock in the sea floor and deacidifies the ocean.
While this rock is abundant and cheap, all of the unweathered sources of it are underground. The plan is to mine it, grind it, and spread it on beaches to harness the free energy of wave motion to further tumble the rocks and accelerate the weathering process. We will be creating a global network of green sand beaches to stem the tide of carbon dioxide induced global warming.
1 ton of olivine sequesters 1.25 tons of carbon. A volume of 7km^3 of olivine spread over the world's 2% most tidally active areas would off-set all of humanity's yearly CO2 output.
Olivine (Mg2SiO4) + 4 CO2 + 4 H2O −→ 2 Mg^2+ + 4HCO3^- + H4SiO4
CO2 is consumed, and Mg2+, Fe2+, H4SiO4 and HCO3^- are produced
Phase I: The "Seasaw"
Phase II: Impact Beach
The world's first intentional green sand beach. With each 1 ton of olivine added, sequestering 1.25 tons of carbon dioxide. Individuals and organizations would be able to sponsor the placing of olivine to offset their carbon footprint. This beach and its sister projects will prove our concept and become ecotourism destinations.
As the CO2 dissolved in the water interacts with the molecules in olivine, a natural reaction occurs that results in a bicarbonate solution that traps the CO2, where it gets converted by marine organisms into corals and shells and eventually forms rock.
The bicarbonate solution resulting from the weathering of olivine also happens to be alkaline. This is an amazing property because alkalinity is needed to counteract the increasing acidification of the water, which causes coral bleaching and other critical problems.
As animals digest the olivine grains to build their shells, they speed up the weathering process by up to 1,000 times and release silica. Silica is the limiting factor for diatoms, a type of phytoplankton that is a crucial food source for fish and birds.
Phase III: First Carbon Neutral Country
The race to become the first carbon-neutral country is on and accelerated weathering of olivine is the only technique in existence that is scalable, financially viable, and can be started today.
As an example, Costa Rica has pledged to be carbon neutral by 2021, but each each citizen is responsible for approx. 1.6 tons of CO2 per year mostly from transportation. This equates to less than $30 per person of olivine. By lining the coasts of Costa Rica with 11.68m tons of olivine, they could be carbon neutral on schedule.
Any country with warm waters and continental shelf seas has an opportunity for accelerated weathering. Costa Rica has a shoreline of 1,016 km on the Pacific side, most of which would be suitable for olivine weathering. Inland countries or those with non-optimal beaches could partner to provide olivine.
Phase IV: Regional Offsets
Countries and specific regions with opportune, high-energetic marine environments could partner to offset their CO2. Part of the continental shelf between the Shetland Isles and France, known as the Southern Bight of the North Sea, has an ideal area of over 35,000 km^2.
Negative Emissions Initiative
A volume of just 0.35 km^3 of olivine grains, applied at 1 cm thickness to the accessible coastlines of countries adjacent to the Southern Bight (UK, France, The Netherlands, Belgium and Ireland), would offset about 5% of humanity’s yearly CO2 output. Yet these countries only contribute about 4% of the worlds CO2 emissions, so they would effectively all be carbon negative.
The Southern Bight is an exceptional project location, as the seafloor itself has strong enough bed shear stresses and currents to tumble olivine. In this region, beaches would not even be necessary. Ships could simply dump the 1.2 Gt of olivine directly in the water.
Phase IV: Regional Offsets
Borders are human created instruments that do not represent our interconnected planet and environment. Regions of the world could partner together to utilize the optimal geography where present, working on massive projects taking advantage of those countries with adequate coastlines and others with adequate olivine deposits.
Phase V: Global Beachheads
There are massive massifs of dunite, which contain greater than 90% olivine, distributed globally. In order to reduce CO2 from transport, it is best to create beaches near the source of the material. So each of these dots represents a potential area to create a nearby country or regional accelerated olivine weathering project. Combined, the world only needs to distribute a volume of 7 km^3 of olivine across the 2% most tidally active beaches to sequester 100% of humanity's yearly CO2 emissions.
Olivine is an abundant mineral and one of the most common by volume, making up nearly 50% of the upper mantle. In order to mine enough of it to offset human-caused CO2, we would have to open between 30-50 new mines. There individual mines of other types of rock that have excavated volumes greater than 25 km^3.
Economy of Scale
At current prices, olivine is already extremely cheap solution per ton of CO2 sequestered and is the most viable technique available to reliably, scalably sequester carbon. Today, crushed olivine can be purchased at the port of Rotterdam for about $25/ton, but through economies of scale, we hope to bring the price down to about $10/ton of CO2 captured.
Climate change is going to cost the world trillions of dollars in damage and lost economic value. For just $250 billion per year, however, the entire world can offset their CO2 output with olivine. This is meant to buy time for countries while they work to cease their CO2 release. Once countries are fully neutral, olivine can continue to be dumped in order to restore the climate back to pre-industrial CO2 levels.