Frequently Asked Questions

Climate change is already affecting every region of the world.

There has been an increased occurrence of heatwaves, deadly and damaging fires, extreme rain, droughts and tropical cyclones causing displacement, food insecurity and increased mortality. In 2024, global heat records are being broken almost every month, as extreme weather becomes more frequent.

To stabilize the climate and help limit global warming, reducing and preventing emissions of greenhouse gases (GHG) is not enough. We have already emitted an excessive amount of carbon dioxide (CO₂) in the atmosphere over the past 200 years of industrialization.

Carbon dioxide removal (CDR) is a term used to cover the various methods that remove CO₂ directly from the atmosphere, and store it away to prevent further damage to the climate.

To keep global warming to 1.5°C, the world’s scientists agree that we need to remove up to 10 billion tonnes of CO₂ each year by 2050.

That being said, CDR should not be treated as a substitute for the reduction of global GHG emissions.  Both reductions and removals are needed.

See the Carbon Business Council issue brief about defining Carbon Removal - https://www.carbonbusinesscouncil.org/news/definingcdr

Sources:

IPCC, 2023: Climate Change 2023: Synthesis Report. Contribution of Working Groups I, II and III to the Sixth Assessment Report of the Intergovernmental Panel on Climate Change [Core Writing Team, H. Lee and J. Romero (eds.)]. IPCC, Geneva, Switzerland, pp. 35-115, doi: 10.59327/IPCC/AR6-9789291691647.

Torkington, Simon. “Periods of Extreme Heat Are Becoming More Common - This Is What You Need to Know.” World Economic Forum, August 21, 2024. https://www.weforum.org/agenda/2024/08/extreme-heat-climate-change/.

Arca asserts that carbon dioxide removal (CDR) must be:

• Permanent - carbon removal must be durable over timescales comparable to the atmospheric lifetime of carbon emissions, at least 1000 years.
• Net negative - approaches must result in a net reduction in the amount of carbon dioxide in the atmosphere.
• Additional - the carbon removal would not have otherwise occurred.
• Verifiable - using scientifically rigorous and transparent methods to monitor, report and verify that the removals have occurred.

It is important to understand that we must invest now in building the CDR industry so it is ready to remove at least 10 billion tonnes of atmospheric carbon dioxide per year by 2050.  The need for the emergence of an entirely new industry at this scale, in this timeframe, is an unprecedented challenge and an unprecedented opportunity.

Arca is an active member of the Carbon Removal Alliance (https://carbonremovalliance.org) and the Carbon Business Council (https://carbonbusinesscouncil.org) and contributes to working groups that develop policy recommendations to support the emergence of the CDR industry.

If we are to stabilize our climate in the face of climate change, we need to dramatically reduce emissions of greenhouse gases. The term “Emissions Reduction” refers to the strategies and technologies that reduce future release of carbon dioxide and other greenhouse gasses into the atmosphere. These include process improvements, switching to renewable energy and sustainable business practices.

Carbon Capture is about capturing industrial carbon dioxide emissions before they are released into the atmosphere.  Carbon Capture, Utilization, and Storage (CCUS) is commonly used to describe this process of ‘scrubbing’ CO₂ from a point source like a power plant that burns fossil fuels. The carbon dioxide can then be stored underground or used for other industrial processes. CCUS has been around for many years and is a relatively mature industry.

Carbon dioxide removal (CDR) involves directly extracting existing CO₂ from the atmosphere, rather than preventing new emissions at the source. It will be needed to reverse the damage to our environment from the use of fossil fuels. CDR at scale could also help stabilize the climate as we reduce greenhouse gas emissions over the energy transition away from fossil fuels.

CCUS and CDR are very distinct methods with different roles to play in fighting climate change.  Both are needed in addition to emissions reduction.

Carbon dioxide removal credits are financial instruments that represent a specific amount of carbon dioxide that has been removed from the atmosphere, verified and stored securely.  1 CDR credit represents 1 tonne of atmospheric carbon dioxide that has been permanently and verifiably removed.

These credits are traded in carbon markets, allowing individuals and companies to purchase them to offset emissions. They are critical in the fight against climate change, providing a way to financially support and scale carbon removal efforts.

There are different methods, commonly known as ‘pathways’, to remove carbon dioxide from the atmosphere.  Each pathway involves a different mix of technologies and inputs.

The prestigious XPRIZE Carbon Removal competition (Arca is a top 20 finalist) grouped its finalist teams into four broad CDR pathways: air, land, oceans and rocks. See the report and its classification scheme here.

Here is another great resource produced by the UN to help make sense of the different pathways.

Industrial Mineralization (IMin) is a CDR pathway that is designed to scale. It leverages existing industrial infrastructure and repurposes alkaline industrial waste streams to capture and permanently store atmospheric CO₂ as stable minerals through carbon mineralization.

Carbon mineralization is a natural geochemical process that occurs in certain special types of rocks and alkaline industrial waste materials (i.e. steel slag). It is a series of chemical reactions in which CO₂ bonds with magnesium- and calcium-bearing silicate minerals, such as olivine ((Mg,Fe)₂SiO₄) and, serpentine (Mg₃Si₂O5(OH)₄), producing stable solids like magnesite (MgCO₃) and calcite (CaCO₃).

Carbon mineralization has been shaping Earth’s atmosphere for hundreds of millions of years, drawing down atmospheric CO₂ and locking it away as rock. However, this occurs over geological time scales (i.e., very very slowly). Decades of geoscience research, combined with recent engineering advances, now make it possible to accelerate carbon mineralization by orders of magnitude—making CO₂ capture millions of times faster.

Moreover, alkaline industrial waste materials - coal ash, steel slag, cement kiln dust and mine tailings - contain all the right elements and minerals for industrial-scale carbon mineralization. These waste piles are already at the surface, often stockpiled within existing industrial footprints.

Industrial Mineralization leverages these solid industrial waste streams to remove a gaseous industrial waste stream (excess carbon dioxide in the atmosphere). The result is more than cleanup; it’s a pathway to safe, durable, gigatonne-scale carbon removal - turning liabilities into assets and waste into repair.

Arca is a leading Industrial Mineralization company, pursuing engineered mineralization projects at industrial sites globally. Our technologies repurpose existing industrial alkaline waste materials, accelerate carbon mineralization and quantifiably measure each step of the process to support robust third-party MRV and carbon removal crediting.

Arca works with industrial partners such as mining companies and steel producers to drive the valorization of historical waste for high-quality durable carbon removal.

Industrial Mineralization is a distinct pathway, where patented technologies, like Arca's, accelerate the natural process of carbon mineralization. It incorporates many of the following features:

• Utilizes carbon mineralization - Under the right conditions, carbon mineralization occurs spontaneously, making IMin energy-efficient and cost-effective. It locks CO2 in stable carbonate minerals (e.g., magnesite, calcite) for 10,000+ years.
• Abundant feedstocks: IMin utilizes alkaline industrial waste materials, gigatonnes of which exist on the surface of the Earth in legacy waste piles.
• High scalability: By tapping into the infrastructure and expertise of industrial partners, IMin can scale to gigatonne levels more rapidly.
• Low resource intensity: IMin integrates into existing industrial sites, allowing for scaling without placing additional pressure on land or water resources.
• Economic incentives: IMin creates valuable co-benefits for industries, such as improving the stability of mine tailings or transforming burdensome waste materials into revenue generating assets, accelerating both carbon removal and waste management.
• Employs robust MRV: IMin includes direct measurement of solid carbonate formation, verified by established geochemical and analytical techniques.

As pressure mounts to scale high-integrity, durable carbon removal, IMin has emerged as a cost effective, light-footprint, infrastructure-compatible solution that turns waste liabilities into climate assets.

Certain heavy industries have the potential to remove large amounts of carbon dioxide from the atmosphere. With our technology, we can harness the huge global footprint of these operations to transform them into a massive carbon sink.

Let's take mining for example. Humans have been mining for thousands of years.  Every mine produces waste material: rock that has to be moved in order to expose the commodity-bearing ore (this is called waste rock); or the leftover rock after the commodity has been separated from the ore (called tailings).  Mines that have extracted all the commodity are then de-commissioned and are known as ‘legacy’ mines.

Our research indicates that there is a huge one-time opportunity in legacy industrial waste, with a potential to store 21 gigatonnes of CO₂ from mine waste and gigatonnes more from other streams of alkaline industrial waste. There is also an annual opportunity to store 723 million tonnes of CO₂ in fresh waste from active, operating mines.

“Durability” of carbon removals refers to the length of time before the CO₂ returns back to the atmosphere. Typical solutions which store carbon in the biosphere (e.g. planting new forests, processing biomass, etc.) have significantly lower durability compared to solutions which store carbon in geological formations (e.g. mineralizing carbon in alkaline waste, ocean floor, underground rock formations, etc.)

Carbon dioxide removed from the atmosphere by Arca is stored for 10,000+ years.

Planting trees can be a fast way to remove atmospheric carbon dioxide, but they cannot be understood as a durable way.  For example, a forest fire releases many tonnes of CO₂ stored in trees and other biomass as they burn.

Rainforests, particularly tropical rainforests, are highly efficient at absorbing large amounts of atmospheric carbon dioxide through the process of photosynthesis.  Protecting rainforests from being logged or burned is a way to ensure this vital role continues, and it also prevents carbon dioxide from being emitted.

Arca’s technologies transform CO₂ into rock, forming carbonate minerals that are chemically stable and insoluble. It would be nearly impossible for this CO₂ to be released back into the atmosphere due to natural processes. This gives Arca’s removals high durability.

Arca generates highly durable, highly verifiable carbon removals. Our capital-light, modular solutions leverage existing industrial footprints, require no additional land, transportation needs, and minimal energy to remove CO₂, making them cost effective compared to most high quality CDR alternatives.

Additionally, Arca leverages industrial waste, transforming it from a liability to a revenue-generating asset in the form of  a valuable carbon sink.

Arca partners with producers of critical minerals and the industrial materials sector to transform industrial waste into massive carbon sinks. Each site is a little different. We deploy a bespoke selection of our technology portfolio depending on factors such as geology, topography and local climate.

Smart Churning is one technology in Arca’s portfolio, and is the process by which Arca’s autonomous rovers are equipped with custom tillers that churn the surface of tailings to optimize their water content, alkalinity, and surface roughness.

Smart Churning is optimized by Arca’s measurement, reporting, and verification (MRV) system, enabling us to customize our churning techniques in response to real-time data. Through this optimization, smart churning can sustain elevated rates of carbon capture compared to baseline.

Mineral Activation is another technology in Arca’s portfolio.  It is an engineered process that breaks down the mineral lattice structure of the rocks that Arca is processing.

Arca uses Mineral Activation to increase the CO₂ reactivity of minerals that are naturally capable of carbon mineralization (e.g., serpentine minerals). When these minerals break down, reactive elements such as magnesium or calcium are released to bind with CO₂.

Arca’s Mineral Activation technology uses microwave radiation to break down mineral structures, an approach that is fully electric and requires substantially less time than traditional methods.

Arca has built one of the world’s most advanced laboratories to explore the science and technology of carbon mineralization in alkaline industrial waste streams.  Our technology portfolio is constantly expanding.

Resource extraction produces the largest waste stream, by volume, in the world, yet critical mines provide the minerals needed for the clean energy transition. Arca is able to help mining companies address their carbon reduction goals by using their vast waste products and existing footprint to capture CO₂.

Our carbon dioxide removal technology accelerates the natural process of carbon mineralization, transforming mine tailings into valuable resources, and critical metal mines into massive carbon sinks.

Carbon mineralization provides a new waste-to-value pathway for the mining industry. Mine tailings used for the carbon mineralization process reduce the environmental hazards associated with mine waste while also capturing CO₂.

Besides carbon dioxide removal, potential benefits to mining companies include:

• Tailings stabilization: During carbon mineralization, new solid carbonate minerals are formed. These newly-formed minerals have the potential to stabilize tailings slurries.
• Metals recovery: In certain cases, treatment of mine waste for mineralization can enhance recovery of metals.
• Diversification of revenue sources: Carbon mineralization can be an alternative revenue source, by generating carbon dioxide removal credits that can be sold in carbon markets.

The term “ultramafic” refers to rocks rich in magnesium (Mg) and iron (Fe).  (“Mafic” rocks have lesser amounts of Mg and Fe.) These types of rock are commonly found in association with deposits of nickel, chromium, platinum group metals, diamond, and asbestos.

We are currently focusing on critical metals mining due to its importance to the clean energy transition and the gigatonne-scale potential of its waste. However, Arca’s CDR pathway is applicable to other alkaline waste streams as well, such as mafic mine waste and waste produced from iron, aluminum, steel and cement industries.

We are always looking out for new partners for our carbon dioxide removal technology. Please reach out to us at info@arcaclimate.com.

Through a natural process called “carbon mineralization”. Carbon mineralization refers to the conversion of gaseous CO₂ into a stable carbonate mineral. In the context of slag, calcium (Ca) and to a lesser extent magnesium (Mg), dissolve from the slag and react with CO₂ to form extremely durable minerals at these conditions. The reaction for Ca can be written as:

Ca²⁺ (dissolved from slag) + CO₂ (from air) = CaCO₃ (calcium carbonate, or calcite)

Unlike other forms of CO₂ capture, carbon mineralization provides capture of CO₂ and its permanent storage in a single step. ​

At Arca, we deploy our leading-edge technologies to valorize traditional waste, like steel slag, from the industrial materials sector. We engage in profit sharing with our Industry Partner, and the exact proportion of the share is dependent on a different factors, such as financial or logistical investment and deployment support.

We sell carbon dioxide removal credits to corporate buyers seeking to meet net zero goals.

Pricing depends on the size and length of the CDR purchase contract. In general, it is significantly lower than most comparable CDR offerings in the market today.

If you are considering purchasing durable CDR credits for your business, please contact us at investors@arcaclimate.com for more details.

Arca’s customers are businesses that have set long term science-based targets for eliminating their net CO₂ emissions, and value the high quality and durability of Arca’s credits.

If you are considering purchasing durable CDR credits for your business, please contact us at investors@arcaclimate.com for more details.