Mining’s Carbon Removal Opportunity Is Huge, But RMI Warns It Must Be Built on Safety, Science and Social Licence

SINGAPORE, August 25, 2026 : The mining industry could become one of the most important industrial platforms for durable carbon dioxide removal, but only if projects are developed with rigorous safeguards, credible measurement and clear community benefits, according to a new RMI report.

The report, Mining and Carbon Dioxide Removal: A Responsible Path Forward for Mine Operators, Policymakers, and other Key Stakeholders, argues that mining and CDR are increasingly converging because many carbon removal pathways need the same materials, land, equipment, infrastructure and operational expertise that already exist at mine sites. RMI defines CDR as human-induced activity that removes CO2 from the atmosphere and stores it in geological, terrestrial or marine reservoirs, or in durable products, over timescales of decades to millennia. It also distinguishes CDR from point-source capture and storage, where CO2 is captured from an industrial source rather than directly or indirectly from the atmosphere.

The report’s central estimate is striking. RMI says CDR at mining sites could yield more than 1 billion tonnes of CO2 impact per year at costs that could be competitive with other forms of durable carbon removal, while potentially improving mine safety, productivity and earnings.

That figure is not presented as a simple deployment forecast. RMI is careful to note that its calculations are theoretical and do not consider all practical or regulatory constraints. But the size of the opportunity is still significant because mining has something the carbon removal industry urgently needs: large volumes of alkaline minerals and industrial infrastructure capable of handling materials at scale.

Why Mining Matters to Carbon Removal

The report is motivated by a basic reality of the carbon removal sector: geochemical CDR methods depend on minerals.

RMI notes that while the world is still early in proving which CDR approaches are most effective, a portfolio of methods will be needed. Geochemical methods, which rely on alkaline minerals and therefore on mining, are expected to be an important part of that portfolio. At the same time, mining itself is set for growth as economies demand more critical minerals and materials for development and the energy transition.

This creates both opportunity and risk.

Mining already generates large volumes of tailings, waste rock, overburden, process water and other materials. Some of these waste streams contain mafic and ultramafic rocks rich in minerals that can react with CO2 and lock it away as solid carbonates or dissolved bicarbonates. Mining sites also have land, equipment, permitting experience, processing infrastructure and technical teams capable of dealing with large-scale material handling.

RMI describes “Mining CDR” as the full set of synergies between mining activities, assets and infrastructure and various CDR applications. These can include mineralising tailings and waste rock, using closed mine sites for biomass burial or reforestation, remediating legacy asbestos mines, and sequestering captured carbon in reactive minerals while recovering critical minerals.
The report identifies several ways in which CDR can be integrated into mining value chains: waste valorisation, commodity production, asset optimisation, closure optimisation and feedstock provision for offsite CDR approaches such as enhanced rock weathering and ocean alkalinity enhancement.

In practical terms, this means a mine could deploy CDR directly onsite, provide mineral feedstock to a third-party CDR project, use CDR to improve closure outcomes, or generate additional products such as low-carbon construction materials or recovered metals.

The Biggest Opportunity Is in Tailings and Legacy Waste

The most immediate opportunity lies in mineralisation-based CDR.

RMI estimates that mineralising tailings generated each year from mafic and ultramafic mines could theoretically support around 100 million to 170 million tonnes of CO2 removal per year. Using legacy tailings could raise the theoretical potential to 520 million to 820 million tonnes per year. Biomass burial in sealed subsurface voids could provide a similar magnitude of CDR each year.

The attraction of mine tailings is straightforward. Tailings and waste rock are among the mining industry’s most costly and risky liabilities. They require long-term storage, monitoring and management, and can pose geotechnical, contamination and water risks if poorly handled. If carbon mineralisation can safely strengthen tailings, reduce risk and create verified carbon removal, then mining operators could gain both climate and operational benefits.

RMI points to early evidence that carbon mineralisation may improve tailings stability. At BHP’s Mt Keith operation, increased undrained peak shear strength was observed in nickel tailings through direct aqueous CO2 exposure, with measurable strength gains appearing within weeks. Laboratory work on brucite-bearing ultramafic tailings has also shown cemented specimens with strength levels that could be sufficient in many scenarios to stabilise tailings.

The report is not unqualified in its optimism. It says more testing is needed, especially over sustained periods in operational settings and across different tailings types. Questions remain around longevity, brittleness, permeability, post-peak behaviour, heterogeneous tailings performance, disturbance risks, drainage and water balance.

This is the report’s central balance: mining CDR may be a major climate opportunity, but it cannot be treated as a simple bolt-on technology.

A Business Case Beyond Carbon Credits

For mine operators, RMI frames CDR around two commercial value propositions: risk management and strategic resilience, and monetisation and strategic growth.

On the risk side, the report says CDR applications can potentially reduce site-level liabilities, operating costs and risks through waste transformation, improved geotechnical stability of tailings, improved acid and metalliferous drainage management, and improved pit lake water quality. Responsible integration could also help operators strengthen sustainability reporting, social licence and support from communities, regulators and stakeholders.

On the monetisation side, mine operators can generate carbon credits, embed the carbon value into lower-carbon products that command price premiums or meet regulatory requirements, or apply removals internally to meet corporate targets, internal carbon prices, carbon taxes or emissions trading obligations.

The potential economics are meaningful. RMI says costs for some mining CDR interventions could fall in the range of US$80 to US$300 per tonne, making them competitive with other durable CDR pathways.

In a developed market, the revenue opportunity could be large. RMI gives an illustrative example in which carbon mineralisation at nickel, chromium, titanium, legacy asbestos or other viable mines could generate US$40 million to US$200 million in annual site-level revenue, based on assumptions including 2 million to 4 million tonnes of reactive tailings per site per year, 0.25 tonnes of CO2 removed per tonne of tailings feedstock and carbon prices of US$80 to US$200 per tonne. Across 100 viable sites, that could translate into US$4 billion to US$20 billion annually.

Biomass burial at retired coal mines and other sites in need of backfill material could generate lower site-level revenues, but still represent another potential source of CDR value.

However, the report makes clear that markets, carbon accounting systems and regulatory frameworks for monetising CDR value are still emergent and uncertain.

That matters because the business case cannot rely only on carbon credit expectations. For many sites, the strongest case may come from combining carbon revenue with lower closure liabilities, improved waste management, critical mineral recovery, lower-carbon products and reputational benefits.

The Carbon Market Is Growing, But Still Concentrated

RMI places mining CDR within a carbon removal market that is early but expanding.

The report says durable CDR credit purchasing is currently driven mainly by voluntary corporate buyers, with big technology companies dominating high-volume purchases. It notes that big tech accounted for roughly 80% of purchases in 2024, with Microsoft alone representing about 79% of contracted durable CDR tonnes. More than 100 new buyers entered the durable CDR market in 2025, although their purchase volumes remain modest compared with tech leaders.

This demand structure creates both an opening and a vulnerability for mining CDR. If more buyers seek durable, lower-cost removals, mining-linked pathways could be well positioned. But if demand remains concentrated among a small set of buyers, developers and mine operators may face project finance uncertainty, delivery risk and price volatility.

The report also highlights market and regulatory drivers that could shape demand, including carbon border adjustment mechanisms, emissions trading systems, the Science Based Targets initiative, carbon accounting reform and differentiated products.

For CarbonWire readers, this is one of the most important implications. Mining CDR may not scale only through voluntary credit markets. It could also be pulled into industrial decarbonisation through product standards, low-carbon material premiums, Scope 3 pressure and regulatory frameworks that reward durable removals or penalise high-carbon products.

MRV Is the Gatekeeper

The promise of mining CDR depends on measurement, reporting and verification.

RMI says MRV frameworks for mining CDR are evolving rapidly as measurement technologies and crediting mechanisms mature. But quantifying removals is difficult because of physical uncertainty and operational complexity. The report identifies market and technological challenges, such as uncertainties caused by heterogeneous feedstock composition and the cost of geochemical assessments. It also notes physical challenges, including temporal lags in weathering and mineralisation, where reactions can unfold over weeks to decades.

There are also regulatory challenges. Measurement may require repeated third-party access to mine sites, verification latency may occur when there are delays between carbonation events and third-party verification, and future liability for stored carbon may depend on site ownership after closure.

Durability is another crucial dimension. The report says geochemical CDR can store CO2 over long timeframes of more than 1,000 years, offering greater certainty than many biological sinks. Carbon mineralisation also has low reversal risk because carbon is chemically bound into solid, inert minerals. For weathering and alkalinity approaches, downstream losses remain an important area of ongoing research.

This means the credibility of mining CDR will depend not just on how much material is processed, but on whether removal claims are measurable, additional, durable, conservative and auditable.

Safety and Community Risks Cannot Be Secondary

The report is explicit that CDR on mine sites also creates new risks.

Introducing new activities into active or planned mine projects can create operational errors and negative impacts on safety, production and economics. Handling legacy tailings, waste rock or slag can raise specific challenges including geotechnical stability, drainage, contamination risk and regulatory restrictions on disturbing closed or capped facilities.

RMI identifies risks across critical control management, tailings and waste management, water management, air quality, workforce safety, closure and stewardship, and consumer protection scrutiny. Disturbing tailings can affect stability, drainage, pore pressure, seepage, dusting and contaminant mobility. Weathering, alkalinity addition or CO2 injection can change pH, mobilise metals, affect groundwater or aquifers, alter pit-lake ecology or increase water demand in stressed basins.

Community implications are equally important. RMI says CDR should take place only when projects meet strict criteria and adhere to social and health standards. It notes potential benefits, including toxic metal mitigation, ecosystem restoration, land reclamation, green jobs and local industrial opportunities, but also possible negative impacts such as dust, resource competition, infrastructure buildout and community acceptability concerns.

This is where mining CDR differs from many other climate technologies. It is not deployed in neutral space. It is deployed on sites with histories, liabilities, communities, land claims, water constraints and, in some cases, long-standing distrust. Social licence will therefore be as important as chemistry.

Siting Will Decide What Works

RMI emphasises that site-specific factors will be decisive.

The feasibility of mining CDR depends on geological characteristics, life-of-mine timing, access to reactive feedstocks, energy availability, water availability, land use, infrastructure, biodiversity and community support. Access to energy, or capital to increase renewable energy production, may be constraining. Water can also be a constraint, particularly where local communities already face competing needs.

This means mining CDR cannot be scaled through a one-size-fits-all model. A nickel mine with reactive ultramafic tailings, renewable power access and supportive community engagement may be very different from a legacy site with unstable tailings, water stress and unclear ownership.

The report’s implication is that early deployment should focus on high-quality sites where climate, safety, economic and community benefits can be demonstrated together.

Mining CDR Hubs Could Lower Costs

One of RMI’s most interesting concepts is the idea of Mining CDR Hubs.

The report argues that co-locating more than one CDR project on existing industrial sites could reduce costs and environmental impacts compared with deploying projects individually. Shared infrastructure could reduce resource use and avoid drawing on materials, water and energy needed elsewhere. Common baselining, shared sensor networks and aggregated auditing could also reduce MRV costs.

But hubs would require distributed ownership. RMI says financiers, investors and offtakers can provide upfront capital and long-term purchase agreements; industrial neighbours can use storage or waste heat opportunities; communities can be partners and beneficiaries; regulators can define legal pathways; construction companies can buy carbonated materials; technology providers can deploy and optimise systems; and NGOs and researchers can independently evaluate progress.

This hub model may be especially relevant in mining regions with multiple industrial assets, nearby construction demand, renewable energy access and supportive public institutions.

The Responsible Path Forward

RMI’s recommendations are not limited to miners. Mine operators are urged to build internal awareness, evaluate assets and waste streams, match them to CDR solutions, participate in best-practice and standards development, screen projects for feasibility and value, and use project learnings to strengthen best practice and regulation.

Policymakers need to clarify regulatory pathways for pilots, provide visibility on carbon policy and accounting, define safeguards and monitoring expectations, clarify waste reclassification and repurposing pathways, and integrate mine-site CDR into carbon accounting, product regulation, emissions trading and carbon border adjustment mechanisms.

Project developers are asked to design projects that solve problems for mine operators and local communities, share data to improve MRV and carbon accounting, co-design community engagement and benefit agreements, and prioritise safety, risk reduction and verification. Registries, verifiers and NGOs need to build rules for carbon accounting, claims and evidence, while communities should engage early and define priorities around environmental outcomes and shared benefits.

The result is a demanding agenda. But it is also a necessary one.

Mining CDR may offer one of the rare opportunities where industrial decarbonisation, waste remediation, carbon removal, critical minerals and local economic development can intersect. But that promise depends on disciplined execution.

If mining CDR is treated mainly as a carbon credit opportunity, it risks repeating the credibility problems that have affected parts of the voluntary carbon market. If it is treated as a mine-site risk-management and climate infrastructure strategy, backed by rigorous MRV and community consent, it could become an important part of the durable carbon removal portfolio.

The opportunity is large. The report’s warning is equally clear: mining can help build the carbon removal economy, but only if safety, environmental integrity and social licence are built into the model from the start.