Carbon mineralization is the result of a chemical reaction between carbon dioxide (CO₂) and certain types of rocks. It is a scalable solution capable of removing large amounts of CO₂ from the atmosphere, which in turn can help mitigate climate change. So, we had to ask: what are the best carbon mineralization offsets?

The best carbon mineralization offsets are offered by Climeworks, Neustark, and greenSand which permanently store CO₂ underground, in concrete, or in Olivine rocks, respectively. In addition, CarbonCure, CarbonBuilt, and Silicate all lock away CO₂ in concrete. 

Keep reading to learn more about the best carbon mineralization offsets, how these carbon offset projects work, and what their respective offsetting costs are. At the end of the article, we’ll also share with you how effective carbon mineralization offsets are, what their pros and cons are, and how these offsets can help mitigate climate change.

Here’s What All the Best Carbon Mineralization Offsets Have in Common

Carbon offsets are reductions in carbon emissions that are used to compensate for carbon emissions occurring elsewhere. They are measured in tons of CO₂ equivalents and are bought and sold through international brokers, online retailers, and trading platforms on what is known as the global carbon offset market.

“Carbon offset: a way for a company or person to reduce the level of carbon dioxide for which they are responsible by paying money to a company that works to reduce the total amount produced in the world, for example by planting trees”

Oxford Dictionary

Carbon mineralization is a form of technological carbon removal, the process of eliminating carbon from the atmosphere. More specifically, it is the removal of carbon from the atmosphere by sequestering it in permanent reservoirs.

“Carbon Removal: the process of removing CO₂ from the atmosphere”

The Intergovernmental Panel on Climate Change

Carbon mineralization, also referred to as enhanced weathering, refers to the process by which atmospheric CO₂ reacts with silicate material and rocks rich in calcium and magnesium (e.g., basalt rocks).

“Carbon mineralization: the process by which carbon dioxide becomes a solid mineral, such as a carbonate. It is a chemical reaction that happens when certain rocks are exposed to carbon dioxide”

The United States Geological Survey 

There are two main types of carbon mineralization:

• Injecting CO₂ into underground rock formations
• Exposing CO₂ to broken pieces of rock at the Earth’s surface

Underground, CO₂ is injected into wells that lead to igneous or metamorphic rock formations. At the surface, CO₂ is exposed to basalt rocks, ultramafic rocks, or mine tailings (mine waste). Both approaches permanently lock away atmospheric carbon for thousands of years.

These Are the Best Carbon Mineralization Offsets in 2024

Below are our favorite carbon mineralization offsets (you can click on their link to directly jump to their section in this article):

Climeworks: The Leader in Direct CO₂ Removal

Climeworks is a Swiss direct air capture company founded in 2009 by engineering university students Jan and Christoph, who were both shocked at the melting glaciers in the Swiss Alps. Today, their mission is to inspire one billion people to remove CO₂ from the air and reverse climate change.

“Let’s reverse climate change”

Climeworks

Project overview: Climeworks’ process can be divided into two parts: carbon capture and carbon storage. Climeworks has specialized machines that first capture CO₂ from the air. They then partnered with Icelandic company Carbfix to turn the captured CO₂ into stone in less than two years. Carbfix dissolves the captured CO₂ in water and injects it underground where it reacts with basalt rock to form solid minerals via natural processes. To date, they have injected over 70,000 tons of CO₂ at their Icelandic site.

Carbon offset effectiveness: Climeworks offsets are permanent, measurable, and effective. Carbfix’s process is based on scientific research and has been proven successful at an industrial scale.

Carbon offset costs: Climeworks offers monthly, one-off, or gift carbon purchase options at a cost of $1.20 per 1kg of CO₂ removed. 

How to get your carbon offsets: You can get your carbon offsets directly from Climework’s webshop, where you can also select how much CO₂ you want to remove along with your preferred frequency (monthly, one-off, or gift).

Neustark: Locking Away CO₂ in Concrete

Neustark was founded in 2019 by Johannes Tiefenthaler and Valentin Gutknecht on the shared vision of a solution for the utilization and storage of CO₂. Today they have developed technology that produces one of the most climate-friendly concrete. Their mission is to reduce the global construction industry’s carbon footprint by 1 billion tons of CO₂ per year by 2050.

“Co₂ncrete Solutions. Today.”

Neustark

Project overview: Neustark removes CO₂ from the atmosphere and permanently stores it in recycled concrete via the process of mineralization, what they call their ‘Carbon Dioxide Removal (CDR) service’. Approximately 10kg of CO₂ are stored per cubic meter of concrete, and up to 20kg of CO₂ emissions are avoided in the concrete production process. This results in a carbon removal efficiency of 95%.

Carbon offset effectiveness: Neustark’s carbon credits are permanent, safe, and only issued for net carbon removal. Their process is also credited by the Gold Standard.

Carbon offset costs: Costs are determined after initial contact.

How to get your carbon offsets: You can contact a Neustark representative to get your carbon offsets.

greenSand: Olivine – The Great CO₂ Cleaner

greenSand was founded in 2009 by Eddy Wijnker after he realized that Olivine, a mineral, had the potential to clean up CO₂. Today, they offer carbon offsets for individuals and businesses and have developed products of olivine-rich rocks that can replace current sand and stone applications. Their mission is to permanently clean up extra CO₂ to bring balance back into the Earth’s CO₂ cycle.

“We save the earth with stones and sand, will you help?”

greenSand

Project overview: greenSand uses Olivine rocks, which trap CO₂ when they come into contact with water. The carbon stored in Olivine rocks is stored permanently, and it is only released if the temperature exceeds 1,600 degrees. For every ton of CO₂ purchased, greenSand spreads 1 ton of Olivine, which can in turn absorb 1 ton of CO₂.

Carbon offset effectiveness: greenSand is Open Natural Carbon Removal Accounting (ONCRA) certified. ONCRA is a framework for measuring the removal and storage of CO₂ via nature-based solutions.

Carbon offset costs: greenSand’s offsets cost $82 per 1,000kg of CO₂ offset.

How to get your carbon offsets: You can visit greenSand’s website to get your carbon offsets.

InPlanet: Enhanced Weathering of Silicate Rocks

InPlanet was founded in 2022 by Felix Harteneck and Niklas Kluger to remove CO₂ and regenerate tropical soils to create a healthy planet for future generations. Today, their mission is to help farmers replace chemicals with natural rock powders from local mines.

“Carbon removal for a liveable planet”

InPlanet

Project overview: InPlanet accelerates the natural process of enhanced weathering by grinding and spreading silicate rocks on tropical soils. The silicate rocks capture and store carbon for thousands of years and help regenerate tropical soils by acting as a long-term fertilizer. InPlanet currently focuses their efforts in Brazil, where the mineral-depleted soils and overall climate are conducive to fast and effective weathering. In the future, they plan to expand to other tropical markets.

Carbon offset effectiveness: InPlanet has partnered with Carbonfuture to join their Catalyst program, which provides carbon removal companies with monitoring, reporting, and verification. 

They have also partnered with Cloverly, a leader in certified carbon offsets.

Carbon offset costs: Costs are determined after initial contact.

How to get your carbon offsets: You can visit InPlanet’s website to contact a representative and get your carbon offsets.

CarbonCure: CO₂ Mineralization in Concrete

CarbonCure was founded in 2012 by Rob Niven to help decarbonize the concrete industry, which is responsible for roughly 7% of global CO₂ emissions. Today, they permanently lock away CO₂ in concrete on their mission to reduce carbon emissions by 500 million tonnes by 2030.

“Cleaner concrete, better business.”

CarbonCure 

Project overview: CarbonCure’s technology targets embodied carbon, or the carbon emitted from manufacturing building materials and construction. Once retrofitted into concrete plants, the technology allows concrete producers to inject captured CO₂ into fresh concrete during mixing. The CO₂ then reacts with the concrete mix and is chemically converted into a mineral, where it is permanently stored for thousands of years. 

Carbon offset effectiveness: CarbonCure’s carbon offsets are permanent, verifiable, and scalable. Their methodology for calculating CO₂ removal is also verified by Verra, a leader in carbon offset standards.

Carbon offset costs: CarbonCure’s subscription plans cost $165 per 1,000kg of CO₂ offset. You can also create a custom plan.

How to get your carbon offsets: You can visit CarbonCure’s website to get your carbon offsets.

UNDO: Enhanced Weathering of Basalt Rocks 

UNDO, an offshoot of the Future Forest Company, was founded in 2020 by Jim Mann as a way to undo years of carbon emissions via enhanced weathering. Today, their mission is to become the first company to remove 1 million tons of CO₂.

“Putting carbon in its place”

UNDO

Project overview: UNDO accelerates the natural process of enhanced weathering by spreading crushed basalt rock on farmlands, which increases the surface area of the rock and allows for immediate contact with the CO₂ produced by plant roots and soil microbes. The basalt rock absorbs the carbon and locks it away in mineral form for thousands of years.

Carbon offset effectiveness: UNDO’s technology is permanent, rapid, and scalable with a 95% carbon efficiency.

Carbon offset costs: Individual carbon offsets are available as a monthly subscription that costs approximately $0.50 per 1kg of CO_2. Business carbon offsets are determined after initial contact.

How to get your carbon offsets: You can visit UNDO’s business or individual carbon offset webpage to get your carbon offsets.

Heirloom: A Carbon Mineralization Solution

Heirloom was founded in 2020 by Noah McQueen and Shashank Samala on the belief that everyone on this planet deserves to thrive, and climate equity plays a big role in making that happen. Today, their mission is to remove one billion tons of CO₂ from the air by 2035 by engineering the most cost-effective, scalable, direct air capture system.

“Restoring balance to our atmosphere”

Heirloom

Project overview: Heirloom’s carbon removal technology speeds up the process of natural mineralization, whereby minerals absorb CO₂ from the air. They use limestone to capture CO₂ directly from the atmosphere and then inject the CO₂ underground or into concrete, where it is stored permanently. 

Carbon offset effectiveness: Heirloom’s process permanently locks away CO₂ in underground geological formations. The process is permanent, sustainable, and compact.

Carbon offset costs: Costs are determined after initial contact with the Heirloom team.

How to get your carbon offsets: You can contact an Heirloom representative to get your carbon offsets.

CarbonBuilt: Capturing CO₂ in Concrete

CarbonBuilt was founded in 2020 by Rahul Shendure and Gaurav Santas to create a world where global economic prosperity no longer threatens our climate. Today, their mission is to help concrete manufacturing drive greenhouse gas emissions reduction by using CO₂ and other industrial wastes in a cost-effective manner.

“Carbon for good™”

CarbonBuilt 

Project overview: CarbonBuilt takes CO₂ generated by industrial processes and transforms it into precast concrete, where it remains locked away for 1,000+ years. The result is a 70 to 100+% reduction in the concrete’s carbon footprint. Their carbon credits are generated by removing cement and switching to materials produced with a lower carbon footprint (carbon avoidance) and by using natural mineralization to capture CO₂ from industrial processes (carbon removal). 

Carbon offset effectiveness: CarbonBuilt’s projects are measurable, permanent, and additional.

Carbon offset costs: Carbonbuilt offers a one-time or monthly subscription option for $200 per ton of CO₂ + processing fees.

How to get your carbon offsets: You can visit CarbonBuilt’s website to get your carbon offsets.

Arca: Rocking CO₂ For a Liveable Planet

Arca, formerly known as Carbin Minerals, was founded in 2021 by Greg Dipple, Peter Scheuermann, and Bethany Ladd to reduce mine waste and remove CO₂ from the atmosphere. Today, they use mine waste and the natural process of weathering to permanently lock away CO₂. Their mission is to provide durable carbon removal on a gigaton scale. 

“From underground to rock star”

Arca 

Project overview: Arca utilizes the natural process of weathering, where rocks absorb CO₂ from the atmosphere and turn it into a mineral. Arca has developed research that speeds up the process into a matter of weeks or days, so by partnering with mines, they can transform mine tailings into giant carbon sinks capable of extracting and permanently storing large amounts of CO₂ underground. Arca’s technology is still in the R&D phase, with their pilot project launching at an unnamed mining site. So far they have pre-sold $1 million in carbon credits to Shopify and Frontier.

Carbon offset effectiveness: Arca provides carbon offsets that are permanent and verifiable. 

Carbon offset costs: Costs will be determined after initial contact.

How to get your carbon offsets: You can contact an Arca team representative to get your carbon offsets.

Silicate: Repurposing Concrete to Remove Carbon

Silicate is an Irish start-up founded in 2021 by Maurice Bryson to reimagine agriculture’s role in responding to the climate crisis. Today, they repurpose concrete as part of their mission to permanently remove CO₂ from the atmosphere via enhanced mineral weathering.

“Our process sees surplus concrete in a whole new light.”

Silicate 

Project overview: Silicate is an Irish startup that is leveraging the carbon removal potential of surplus concrete. They grind surplus concrete to dust so that it can be spread on farmlands. The crushed concrete reacts with carbonic acid in the soil to remove CO₂ from the air. Carbonate and calcite, the substances formed by this process, can store the captured CO₂ for thousands of years.

Carbon offset effectiveness: Silicate has partnered with Carbonfuture to join its Catalyst program, which provides carbon removal companies with monitoring, reporting, and verification. 

Carbon offset costs: Costs will be determined after initial contact.

How to get your carbon offsets: You can contact a Silicate team representative to get your carbon offsets.

How Effective and Efficient Are Carbon Mineralization Offsets

In terms of effectiveness, carbon mineralization offsets permanently and quickly remove CO₂ from the atmosphere, keeping it locked away for thousands of years; however, they do not reduce your own carbon emissions, which can lead to greenwashing.

In terms of efficiency, carbon mineralization offsets have low rates of carbon re-emission; however, they are also relatively expensive and are not yet scaled to compensate for our global emissions.

Carbon mineralization offsets are effective at mitigating climate change because they:

• Permanently lock away CO₂ for thousands of years with no long-term monitoring required
• Reduce emissions quicker than natural weathering processes and other nature-based solutions

However, carbon mineralization offsets can also lack effectiveness because they do not reduce your own carbon emissions, which can lead to greenwashing. This occurs when emissions are only offset and not reduced from the source, and the consumer is deceived into thinking they are offsetting their emissions but in reality, they are not.

Carbon mineralization offsets are efficient at reducing CO₂ emissions because they are a permanent process with very low rates of CO₂ re-emission. In addition, even if the rocks are broken, the carbon will remain trapped inside. 

However, carbon mineralization offsets can also lack efficiency because they are one of the most expensive offsets out of all carbon removal methods, behind direct carbon capture (DCC). They are also not yet scaled to compensate for our global carbon emissions, although they could be scaled up to capture 2-4 billion tons of CO₂ per year by 2050.

What Are The 5 Pros and 4 Cons of Carbon Mineralization Offsets

Carbon mineralization offsets are permanent, have a low rate of carbon re-emission, reduce emissions quickly, protect the biosphere, and can help offset emissions that cannot be reduced otherwise. 

Carbon mineralization offsets are one of the most expensive methods of carbon removal, are not yet scaled to compensate for our global emissions, may induce seismic activity, and do not reduce your own emissions, which can lead to greenwashing.

What Are the 5 Pros of Carbon Mineralization Offsets

Carbon mineralization offsets have various pros that make them effective at sequestering carbon from our atmosphere.

What Are the 4 Cons of Carbon Mineralization Offsets

Understanding the drawbacks of carbon mineralization offsets is important when implementing this strategy on a large scale in order to mitigate climate change.

How Can Carbon Mineralization Offsets Help Mitigate Climate Change

Climate change is a severe and long-term consequence of fossil fuel combustion. Carbon mineralization offsets can help mitigate climate change because they permanently eliminate fossil-fuel-derived carbon from our atmosphere which, if left untreated, can remain there for tens of thousands of years and exacerbate the negative effects of climate change.

How is Climate Change Defined

Climate change is arguably the most severe, long-term global impact of fossil fuel combustion. Every year, approximately 33 billion tons (bt) of CO₂ are emitted from burning fossil fuels. The carbon found in fossil fuels reacts with oxygen in the air to produce CO₂. 

“Climate change: changes in the earth’s weather, including changes in temperature, wind patterns and rainfall, especially the increase in the temperature of the earth’s atmosphere that is caused by the increase of particular gasses, especially carbon dioxide.”

Oxford Dictionary

Atmospheric CO₂ fuels climate change, which results in global warming. When CO₂ and other air pollutants absorb sunlight and solar radiation in the atmosphere, it traps the heat and acts as an insulator for the planet. Since the Industrial Revolution, Earth’s temperature has risen a little more than 1 degree Celsius (C), or 2 degrees Fahrenheit (F). Between 1880-1980 the global temperature rose by 0.07C every 10 years. This rate has more than doubled since 1981, with a current global annual temperature rise of 0.18C, or 0.32F, for every 10 years. 

As outlined in the 2015 Paris Climate Agreement, we must cut current GHG emissions by 50% by 2030 and reach net zero by 2050. 

How Do Carbon Offsets Generally Help Mitigate Climate Change

Levels of carbon in our atmosphere that cause climate change have increased as a result of human emissions since the beginning of the Industrial Revolution in 1750. The global average concentration of carbon dioxide in the atmosphere today registers at over 400 parts per million. Carbon offsets can help prevent these levels from increasing even more.

When you hear the words “carbon offset”, think about the term “compensation”. Essentially, carbon offsets are reductions in GHG emissions that are used to compensate for emissions occurring elsewhere. 

Carbon offsets that meet key criteria and verified project standards, are additional and permanent, and are part of projects that are carried out until the end of their lifespan have the best chance of reducing carbon emissions and therefore reducing climate change. 

When we offset CO₂ we also slow the rate of global temperature rise, which in turn minimizes the effects of climate change. 

How Do Carbon Mineralization Offsets Specifically Help Mitigate Climate Change

Carbon mineralization can specifically help mitigate climate change because it eliminates atmospheric carbon, which when emitted, can remain in our atmosphere for a long period of time. Whether via underground injection, concrete, or mine tailings, the process of carbon mineralization permanently locks away CO₂ for thousands of years.

Final Thoughts

Climeworks, Neustark, and greenSand are the best carbon mineralization offsets. InPlanet and UNDO spread crushed silicate and basalt rocks across landscapes to absorb CO₂ whereas CarbonCure, CarbonBuilt, and Silicate trap CO₂ in concrete. On the other hand, Arca is transforming mine tailings into giant carbon sinks, and Heirloom capturing CO₂ in limestone and storing it underground.

Carbon mineralization offsets permanently, quickly, and efficiently lock away CO₂, helping to reduce global atmospheric CO₂ levels. But for all of the good carbon offsets can instigate, they should not be seen as the only solution to climate change. They are effective at reducing CO₂ in the short term, but in the long term, they fail to reduce CO₂ enough. 

When used in conjunction with direct CO₂ reduction measures, carbon offsetting can be much more effective. We should reduce our own carbon footprint as much as possible first, and only then choose the most effective carbon offsets.

Stay impactful,

Sources

• U.S. Environmental Protection Agency: Offsets and RECs -What’s the Difference?
• Britannica: Carbon Offset
• David Suzuki Foundation: Are carbon offsets the answer to climate-altering flights?
• The Economist: Carbon Mineralisation – Permanently store CO₂ by hastening reaction with minerals
• World Resources Institute: Carbon Removal
• Climeworks: Homepage
• Climeworks: Our journey to gigaton scale
• Climeworks: Direct air capture: our technology to capture CO₂
• Carbfix: Homepage
• Carbfix: Proven
• Climeworks: Subscriptions
• Climeworks: Choose the gift of carbon removal
• Neustark: Homepage
• Neustark: Remove
• Gold Standard: GSF Registry
• greenSand: Homepage
• greenSand: Permanent CO₂ Compensation
• greenSand: All Products
• greenSand: We are greenSand
• greenSand: Operation of Olivine Stone
• greenSand: Certificate – CO₂ Compensation
• Open Natural Carbon Removal Accounting: Homepage
• InPlanet: Homepage
• InPlanet: About InPlanet
• CarbonFuture: registry – C sinks
• Cloverly: Homepage
• CarbonCure: Homepage
• CarbonCure: CarbonCure Carbon Credits
• CarbonCure: Technologies
• CarbonCure: CarbonCure | Subscriptions
• Patch: Patch | Checkout
• UNDO: Homepage
• UNDO: Our Story
• UNDO: Enhanced Rock Weathering
• UNDO: Individual
• UNDO: Business
• Heirloom: Homepage
• Linkedin: Heirloom
• Heirloom: About Us
• Heirloom: Product
• Heirloom: Technology
• Carbonbuilt: Homepage
• Carbonbuilt: About Us
• Carbonbuilt: Buy Carbon Credits
• Arca: Homepage
• The University of British Columbia: UBC spin-off companies win $2 million in competition for carbon removal technology funded by the Musk Foundation
• Shopify: Homepage
• Frontier: Homepage
• SustainableBiz Canada: Carbin Minerals becomes Arca, preps for CO₂ pilot project
• Silicate: Homepage
• The Next Web: The new wave of climate tech startups capturing carbon across Europe
• CleanTechnica: Silicate & Inplanet Join Carbonfuture’s Carbon Removal Catalyst Program
• Silicate: Contact
• Edie: Carbon offsetting – How are businesses avoiding greenwashing on the road to net-zero?
• greenSand: Olivine Research & Evidence
• American University: Fact Sheet – Enhanced Mineralization
• Impactful Ninja: How Effective and Efficient Are Carbon Mineralization Offsets? Here Are the Facts
• Impactful Ninja: Carbon Mineralization Offsets: All 5 Pros and 4 Cons Explained
• National Institute of Environmental Health Sciences: Asthma, Respiratory Allergies and Airway Diseases
• National Institute of Environmental Health Sciences: Cancer
• Carbon Brief: Climate change will hit ‘endemic’ plants and animals the hardest, study warns
• United Nations Framework Convention on Climate Change: Paris Climate Agreement
• World Resources Institute: Direct Air Capture – 6 Things to Know
• US Geological Survey: Making minerals – how growing rocks can help reduce carbon emissions
• World Nuclear Association: Carbon Emissions from Electricity
• Natural Resources Defense Council: Global Warming 101
• myclimate: What does “net zero emissions” mean?
• United Nations Convention Framework on Climate Change: The Paris Agreement
• National Oceanic and Atmospheric Administration: Climate Change – Atmospheric Carbon Dioxide
• Terrapass: Carbon Offset Projects
• Carbon Offset Guide: Additionality
• Carbon Offset Guide: Permanence
• American University: Fact Sheet – Carbon Removal