Carbon mineralization is a process that removes carbon dioxide (CO₂) from our atmosphere, and it is one of the most direct ways we can mitigate climate change. So, we had to ask: What are the pros and cons of carbon mineralization offsets?

Carbon mineralization offsets are permanent, reduce CO₂ emissions quickly with low rates of carbon re-emission, and protect the biosphere. However, they are also expensive, are not yet scaled to compensate for our global emissions, and have potentially negative environmental effects.

Keep reading to find out all about what the pros and cons of carbon mineralization offsets are, how you can offset your carbon footprint with them, how they can mitigate climate change, and what better alternatives to carbon mineralization offsets are. 

The Big Picture of Carbon Mineralization Offsets

Carbon offsets are reductions in carbon emissions that are used to compensate for carbon emissions occurring elsewhere. They are measured in tons of carbon dioxide (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 reforestation”

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.

What Are 5 Pros 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. 

Pro #1: Carbon Mineralization Offsets are Permanent

Carbon mineralization offsets permanently remove CO₂ from the atmosphere.

Carbon Mineralization Offset Pro #1

Carbon mineralization offsets are a specific type of carbon offset that store carbon permanently in geological reservoirs. For example, Climeworks’ partner Carbfix turns captured CO₂ into stone by dissolving it in water and injecting it underground where it reacts with basalt rock to form solid minerals. This process locks away CO₂ for thousands of years with no long-term monitoring required.

When comparing carbon mineralization to other methods of carbon removal, like planting trees, we find that carbon mineralization reduces CO₂ emissions more permanently. With nature-based solutions, there is always the risk of droughts, wildfires, tree diseases, and deforestation wiping out newly planted trees, negating permanence and any carbon reduction benefits. 

In short, carbon mineralization offsets permanently remove CO₂ from the atmosphere because storing carbon underground in rock formations is a permanent process. 

Pro #2: Carbon Mineralization Offsets Have A Low Rate of Carbon Re-Emission

Carbon mineralization is a permanent process and has very low rates of CO₂ re-emission.

Carbon Mineralization Offset Pro #2

Because carbon mineralization is a permanent process, rates of carbon re-emission are very low. For example, greenSand Olivine rocks permanently store carbon and will only release that carbon back into the atmosphere if the temperature exceeds 1,600 degrees. In addition, even if the rocks are broken, the carbon will remain trapped inside. 

In short, carbon mineralization is a permanent process, meaning rates of carbon re-emission are very low.

Pro #3: Carbon Mineralization Offsets Reduce CO₂ Emissions Quickly

Carbon mineralization offsets reduce emissions quicker than natural processes and other nature-based solutions.

Carbon Mineralization Offset Pro #3

Carbon mineralization is a natural process that occurs over millions of years. Carbon mineralization projects aim to speed up this process by breaking down silicate rocks into tiny pieces, thereby skipping slow weathering processes.

For example, Carbfix achieves 95% permanent carbon mineralization in under two years. And in comparison, newly planted trees for reforestation offsets could take upwards of 20 years to capture the amount of CO₂ that most carbon offset programs promise. 

In short, carbon mineralization reduces emissions quicker than natural weathering processes and some nature-based solutions. 

Pro #4: Carbon Mineralization Offsets Protect the Biosphere

Carbon mineralization offsets improve air quality and protect ecosystems.

Carbon Mineralization Offset Pro #4

The degradation of air quality as a result of carbon emissions is a serious issue. For example, in 2009, the US government declared CO₂, CH₄, N₂O, hydrofluorocarbons (HFCs), perfluorocarbons (PFCs), and sulfur hexafluoride (S_F6) threats to the public health and welfare of current and future generations. 

Removing carbon emissions from the atmosphere via mineralization would lead to improved public health in terms of asthma, respiratory allergies, airway diseases, and lung cancer. 

Removing carbon from the atmosphere via mineralization also promotes healthy ecosystems, which have been linked with cleaner air, water, and food. 

• Protecting forest habitats increases carbon sequestration and defends against erosion. 
• Protecting agricultural land ensures a robust, secure, and prosperous food system. 
• Protecting aquatic ecosystems ensures a readily available supply of fresh water. 
• Lastly, protecting biodiversity protects human health because many plants and animals are used in modern medicines. 

In short, carbon mineralization offsets permanently remove carbon emissions from the atmosphere, thereby improving air quality and protecting ecosystems.

Pro #5: Carbon Mineralization Offsets Can Help Offset Carbon Emissions That Can’t Be Reduced Otherwise

Carbon mineralization offsets allow us to reduce carbon emissions in ways we wouldn’t be able to accomplish individually.

Carbon Mineralization Offset Pro #5

We already have governmental-level policies in place to reduce carbon emissions, but carbon offsets allow us to reduce emissions from activities where sustainable alternatives are not yet widely available. 

Carbon offsets are designed for situations where your emissions are impossible to reduce. For example, we can only do so much to reduce our individual carbon footprints. Using public transportation, washing with cold water, and switching from single-use to sustainable products lowers our carbon footprint, but it does not eliminate them completely. This is where carbon mineralization offsets come into play, to reduce carbon emissions in other areas as compensation for the remainder of our carbon emissions.

In short, carbon mineralization offsets allow us to reduce carbon emissions in ways we wouldn’t be able to accomplish individually.

What Are 4 Cons of Carbon Mineralization Offsets

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.

Con#1: Carbon Mineralization Offsets are Expensive

Carbon mineralization offsets are one of the most expensive methods of carbon removal. #1

Carbon Mineralization Offset Con #1

Behind direct carbon capture (DCC), carbon mineralization offsets are one of the most expensive offsets out of all of the carbon removal methods. Mineralization offsets currently range anywhere from $82 – $1,200 per ton of CO₂, depending on the type of technology, type of energy source, and scale of the operation. In comparison, reforestation offsets cost approximately $50 per ton. 

Carbon mineralization is also a reactive, rather than proactive, way of dealing with carbon emissions. In this manner, we can continue to use fossil fuels at an accelerated rate. Carbon removal technologies in general are expensive to implement, so there will be little economic incentive to use them until the cost of emitting carbon rises enough to prompt behavioral changes. 

In short, carbon mineralization is one of the more expensive methods of carbon removal. With further research, development, and funding, this could decrease in the coming years. 

Con#2: Carbon Mineralization Offsets Are Not Yet Scaled to Compensate for Our Global Emissions

Carbon mineralization offsets are not yet at a scale where they can compensate for our global carbon emissions.

Carbon Mineralization Offset Con #2

Currently, carbon offsets in general are not sufficient to compensate for all of our carbon emissions. We emit more than 36 billion tons of carbon annually, but carbon offset credits for only ~1 billion tons of CO₂ have been listed for sale on the voluntary market. The number of sellers also exceeds the number of buyers by about 600-700 million tons. 

Carbon mineralization offsets are also not yet scaled enough to keep pace with our global carbon emissions. Because there are relatively few companies engaged in carbon mineralization on a commercial level, the amount of carbon they can sequester is limited. Also, processes, standards, and technologies still need to be developed to ensure proper monitoring, verification, and reporting of carbon sequestration.

Experts estimate that carbon mineralization could be scaled up to capture 2-4 billion tons of CO₂ per year by 2050. For example, Arca’s pilot program involves partnering with mines to transform mine tailings into giant carbon sinks capable of extracting and permanently storing large amounts of CO₂ underground. Likewise, Silicate is a start-up leveraging the carbon removal potential of surplus concrete. They crush and spread concrete across farmlands, where it reacts with carbonic acid in the soil to permanently remove CO₂ from the air.

In short, carbon mineralization offsets are not yet scaled enough to compensate for our global carbon emissions.

Con#3: Carbon Mineralization Offsets May Have Negative Environmental Effects

Water contamination and seismic activity are potential risks associated with carbon mineralization, although further research is needed.

Carbon Mineralization Offset Con #3

Contamination of surface and groundwater is a potential risk associated with carbon mineralization, but proper monitoring and procedures can mitigate this risk. For example, Carbfix injects CO₂-dissolved water, which is denser than pure water, and therefore sinks below the groundwater table, having little interaction with it. And at the surface, there are also negligible effects from injected CO₂.

Injecting CO₂ underground in rock formations could induce seismic activity, depending on the interactions between existing fault lines and pressure alterations in existing rock formations. These risks can be managed with proper monitoring and siting of injection sites. For example, Carbfix conducts independent seismic risk assessments, and injection sites are monitored before and during well-drilling activities.

In short, possible negative environmental effects could include water contamination and seismic activity, although further research is needed.

Con#4: Carbon Mineralization Offsets Do Not Reduce Your Own Carbon Emissions

Carbon mineralization offsets do not reduce your own carbon emissions, which can lead to greenwashing.

Carbon Mineralization Offset Con #4

One of the main limitations of carbon offsetting, in general, is that purchasing a carbon offset does not directly reduce your carbon footprint. It only makes others reduce their carbon footprint to compensate for your carbon footprint. 

If emissions are only offset and not reduced from the source, this could lead to greenwashing, when the consumer is deceived into thinking they are offsetting their emissions but in reality, they are not. Companies accused of greenwashing either invest in non-verified credits, do not prioritize in-house emissions reductions, or double-count carbon credits. Or sometimes, all of the above.

In short, because carbon mineralization offsets do not reduce your own emissions, they could lead to greenwashing.

How Could You Offset Your Own Carbon Footprint With Carbon Mineralization Offsets

The market for carbon offsets was small in the year 2000, but by 2010 it had already grown to represent nearly $10 billion worldwide. The voluntary carbon offset market (VCM) is where everyday consumers can purchase carbon offsets to offset their carbon emissions, and the Ecosystem Marketplace predicts the VCM can grow to $50B by the year 2050. 

Carbon mineralization takes advantage of natural chemical processes and can permanently and quickly remove carbon from the atmosphere, locking it away for thousands of years. Because it has the potential to store large amounts of carbon, it is predicted to make up an increasing share of the VCM. Below are our favorite carbon mineralization offsets.

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.

What Are Better Alternatives to Carbon Mineralization Offsets

If used correctly, carbon mineralization offsets can provide environmental, economic, and social benefits beyond reducing carbon emissions. They have the potential to instigate meaningful environmental change and begin to reverse some of the effects of climate change. 

However, we can’t let this method be a guilt-free way to reduce carbon emissions. Carbon mineralization offsets must be used in conjunction with direct carbon reduction measures until the industry has time to develop, refine, and make the technology more affordable.

These reduction measures don’t have to involve drastic changes either. Actions that may seem minor can have a significant impact because those small changes add up! You can reduce your carbon footprint in three main areas of your life: household, travel, and lifestyle. 

Reduce your household carbon footprint:

• Wash with cold water: Washing clothes in cold water could reduce carbon emissions by up to 11 million tons. Approximately 90% of the energy is used to heat the water, so switching to cold saves also saves energy.

• Replace incandescent bulbs with fluorescent bulbs: Fluorescent bulbs use 75% less energy than incandescent ones, saving energy and thus reducing electricity demand and GHG emissions.

Reduce your travel carbon footprint:

• Fly less: Aviation accounts for around 1.9% of global carbon emissions and 2.5% of CO₂. Air crafts run on jet gasoline, which is converted to CO₂ when burned.

• Walk or bike when possible: The most efficient ways of traveling are walking, bicycling, or taking the train. Using a bike instead of a car can reduce carbon emissions by 75%. These forms of transportation also provide lower levels of air pollution.

Reduce your lifestyle carbon footprint:

• Switch to renewable energy sources: The six most common types of renewable energy are solar, wind, hydro, tidal, geothermal, and biomass energy. They are a substitute for fossil fuels that can reduce the effects of global warming by limiting global carbon emissions and other pollutants.

• Recycle: Recycling uses less energy and deposits less waste in landfills. Less manufacturing and transportation energy costs means fewer carbon emissions generated. Less waste in landfills means less CH₄ is generated.

• Switch from single-use to sustainable products: Reusing products avoids resource extraction, reduces energy use, reduces waste generation, and can prevent littering.

• Eat less meat and dairy: Meat and dairy account for 14.5% of global GHG emissions, with beef and lamb being the most carbon-intensive. Globally, we consume much more meat than is considered sustainable, and switching to a vegan or vegetarian diet could reduce emissions. 

• Take shorter showers: Approximately 1.2 trillion gallons of water are used each year in the United States just for showering purposes, and showering takes up about 17% of residential water usage. The amount of water consumed and the energy cost of that consumption are directly related. The less water we use the less energy we use. And the less energy we use, the less of a negative impact we have on the environment.

Because carbon mineralization offsets are an indirect way and not a direct way of reducing emissions, they alone will not be enough to reduce global carbon emissions significantly. Direct measures of emission reductions, such as reducing individual energy use and consumption, are better alternatives to carbon mineralization offsets. 

Final Thoughts

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. However, they are also expensive, 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.

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

Stay impactful,

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