Introduction
Enhanced Rock Weathering (ERW) is rapidly emerging as one of the most promising carbon removal solutions—offering permanence, scalability, and co-benefits for soil and ecosystems. Why ERW Credits Stand Out: ERW generates permanent removal credits, making it a preferred choice for corporations focused on long-term climate impact.
But not all ERW carbon credits are created equal. In 2025, these five projects stand out for their innovation, transparency, and real-world impact.
What is a Carbon Credit?
A carbon credit represents one metric ton of carbon dioxide (CO2) or its equivalent in other greenhouse gases that has been either removed from the atmosphere or prevented from being emitted. These credits are generated by projects that reduce, avoid, or sequester emissions—such as reforestation, renewable energy, or clean cooking initiatives. Companies, governments, and individuals can purchase carbon credits to offset their own emissions, helping them achieve net-zero or carbon-neutral goals. Each credit is verified by independent third parties to ensure its legitimacy, preventing double-counting and ensuring real climate impact. Carbon credits play a crucial role in financing sustainable development, particularly in regions where traditional funding is scarce, while providing a measurable way to compensate for unavoidable emissions.
What Is Enhanced Rock Weathering (ERW)?
Enhanced Rock Weathering (ERW) is a carbon removal technology that mimics and accelerates Earth’s natural geological process of weathering. When rain, slightly acidic from atmospheric CO2, falls on silicate rocks like basalt or olivine, it triggers a chemical reaction. This reaction breaks down the rocks, drawing CO2 from the air and converting it into stable carbonate minerals. These minerals either remain in the soil, enriching it with essential nutrients, or are washed into rivers and oceans, where they contribute to long-term carbon storage.
The process begins with crushing silicate rocks into fine powder, which increases their surface area and speeds up the weathering reaction. This powder is then spread across farmland, grasslands, or coastal environments. As the rocks dissolve, they not only capture CO2 but also release nutrients such as calcium, magnesium, and potassium into the soil. These nutrients improve soil fertility, boost crop yields, and enhance water retention, making ERW a multifunctional climate solution.
Permanence, Scale, Co-benefits and Effectiveness
One of the most compelling aspects of ERW is its permanence. Unlike some carbon removal methods that store CO2 temporarily in biomass or soils, ERW locks carbon away in mineral form for tens of thousands of years. This makes it a highly reliable solution for long-term carbon sequestration.
Scalability is another major advantage. ERW can be deployed on a global scale, with the potential to remove billions of tons of CO2 annually. It leverages existing agricultural and mining infrastructure, reducing the need for new, energy-intensive systems. Farmers can integrate ERW into their regular practices, applying rock dust alongside fertilizers or soil amendments, which minimizes disruption and maximizes adoption.
Additionally, ERW offers significant co-benefits beyond carbon removal. By improving soil health, it can reduce the need for synthetic fertilizers, lower farming costs, and increase food security. In coastal areas, ERW can help combat ocean acidification by increasing the alkalinity of seawater, which benefits marine ecosystems.
Research and pilot projects around the world are demonstrating ERW’s effectiveness. For example, studies have shown that applying basalt to agricultural fields can remove up to 4–10 tons of CO2 per hectare per year, depending on climate, soil type, and rock composition. In tropical regions with high rainfall and warm temperatures, the weathering process is even faster, making ERW particularly effective in these environments.
As a nature-based solution, ERW aligns with global efforts to restore ecosystems and promote sustainable agriculture. It is gaining traction among policymakers, scientists, and businesses as a practical and scalable tool in the fight against climate change. With ongoing advancements in monitoring, reporting, and verification (MRV) technologies, ERW is becoming an increasingly trusted and viable option for corporations, governments, and individuals looking to offset their carbon footprints permanently.
The 5 Best ERW Carbon Credits of 2025
Project | Verification Standard | Scalability & Deployment | Co-Benefits | Transparency & Data Availability |
|---|---|---|---|---|
| Puro.earth, Isometric | Coastal & agricultural pilots (10,000+ hectares) | Ocean alkalinity, marine biodiversity | Open-source data, real-time monitoring |
| Carbon Business Council | 50,000+ hectares with smallholders | Soil regeneration, farmer income | Satellite MRV, annual impact reports |
| Gold Standard, Climeworks | Integrated with DAC, 100,000+ tons/year | Geological storage, energy synergy | Peer-reviewed papers, live dashboards |
| Puro.earth | 1M+ tons contracted, 20+ countries | Soil health, water retention | Blockchain-tracked credits, farm-level data |
| Isometric, Puro.earth | 30,000+ hectares, focus on marginal lands | Biodiversity, carbon farming | Self-integrating accumulators (SIAs), real-time data dashboards |
Project Vesta
Overview
Project Vesta accelerates CO2 removal by spreading olivine sand on coastal environments, harnessing the power of wave action to enhance mineral weathering. This process, known as Coastal Enhanced Weathering (CEW), permanently stores CO2 as bicarbonate in seawater, while also reducing ocean acidification.
The project is backed by rigorous scientific research and field trials in the Caribbean, Hawaii, and India, with plans to expand globally. Project Vesta operates as a Public Benefit Corporation, emphasizing transparency and open-source data sharing to advance the science of CEW.
Type: Coastal Enhanced Weathering (CEW)
Location: Caribbean, Hawaii, India (pilot sites), with future expansions planned in the US, France, and the Dominican Republic
Annual Impact: Potential to remove up to 1 trillion tons of CO2 at full scale (equivalent to ~50% of annual global emissions if deployed on 1% of global shelf seas)
Key Benefits
Climate: Permanently removes CO2 from the atmosphere and stores it in the ocean for tens of thousands of years.
Ocean Health: Counters ocean acidification, supporting marine biodiversity and coral reef resilience.
Community: Engages local communities in coastal restoration and creates jobs in monitoring and deployment.
SDGs: Aligns with SDG 13 (Climate Action), SDG 14 (Life Below Water), and SDG 17 (Partnerships for the Goals).
Why It Stands Out
Project Vesta is the first organization to focus exclusively on coastal ERW, a less explored but highly scalable pathway for carbon removal. By leveraging natural wave energy to accelerate weathering, the project minimizes energy inputs and operational costs. Its commitment to open science—sharing data, methodologies, and findings with the global research community—sets a new standard for transparency in carbon removal. The project’s potential to address both climate change and ocean degradation makes it a dual-purpose solution with far-reaching ecological benefits. With backing from organizations like Stripe Climate and TreadRight, Project Vesta is poised to redefine how we approach marine-based carbon removal
Eion: Community-Driven Agricultural ERW
Overview
Eion deploys olivine, a fast-weathering silicate mineral, on farmland across the Mid-Atlantic US, Kenya, and beyond. Using a patented "soil fingerprinting" method, Eion directly measures carbon removal by tracking trace elements like magnesium and nickel in the soil. This approach ensures accurate and scalable MRV (Measurement, Reporting, and Verification). Eion partners with agricultural cooperatives, including Growmark, to integrate ERW into existing farming practices, making it accessible to smallholder farmers. The company has secured major offtake agreements with Microsoft, Google, Shopify, and Frontier, positioning it as a leader in the agricultural ERW space.
Type: Agricultural Enhanced Rock Weathering (ERW)
Location: Mid-Atlantic US, Kenya, and expanding to the Midwest and South
Annual Impact: Contracts to remove 78,000+ tons of CO2 by 2030, with a farmer network covering nearly 400,000 acres
Key Benefits
Climate: Provides permanent, verifiable CO2 removal while improving soil health.
Agriculture: Replaces synthetic lime with olivine, reducing costs for farmers and boosting crop yields.
Community: Creates additional income streams for farmers through carbon credit sales and supports rural economies.
SDGs: Aligns with SDG 2 (Zero Hunger), SDG 13 (Climate Action), and SDG 15 (Life on Land).
Why It Stands Out
Eion stands out for its innovative MRV technology, which integrates seamlessly with existing soil testing practices used by farmers. This makes it one of the most scalable and farmer-friendly ERW solutions available. The company’s partnerships with tech giants and agricultural cooperatives demonstrate its ability to bridge the gap between climate science and real-world deployment. By focusing on acidic soils in warm, wet climates—where weathering rates are highest—Eion maximizes both carbon removal efficiency and co-benefits for food security. Its recent $33 million offtake deal with Frontier underscores the market’s confidence in its approach
Carbfix: Geological Storage in Iceland
Overview
Carbfix captures CO2 from industrial sources and direct air capture (DAC) systems, dissolves it in water, and injects it into basaltic rock formations in Iceland. Within two years, over 95% of the injected CO2 mineralizes into solid carbonate, ensuring permanent storage. Carbfix operates at the Hellisheiði Geothermal Power Plant, where it has reduced CO2 emissions by 30% since 2014. The project is now scaling up through the EU-funded Silverstone initiative, which aims to achieve near-zero emissions at the plant by 2025. Carbfix also collaborates with Climeworks to combine DAC and mineralization, creating a closed-loop carbon removal system.
Type: In-Situ Mineral Carbonation (ERW + DAC integration)
Location: Hellisheiði and Nesjavellir Geothermal Power Plants, Iceland
Annual Impact: Over 100,000 tons of CO2 mineralized annually, with plans to scale to millions of tons
Key Benefits
Climate: Offers the fastest and most permanent CO2 storage solution, with mineralization completed in under two years.
Energy: Enables carbon-negative geothermal energy production.
Innovation: Proves the feasibility of integrating ERW with DAC for hybrid carbon removal.
SDGs: Aligns with SDG 7 (Affordable and Clean Energy) and SDG 13 (Climate Action).
Why It Stands Out
Carbfix is the world’s first operational CO2 mineral storage project, demonstrating that large-scale, permanent carbon removal is achievable today. Its partnership with Climeworks at the Orca DAC plant showcases how ERW can complement other carbon removal technologies to create synergistic solutions. The project’s success has inspired similar initiatives worldwide, including a new feasibility study for basalt storage in the Pacific Northwest. By turning CO2 into stone, Carbfix eliminates the risk of leakage and sets a benchmark for durability in carbon removal
UNDO: Blockchain-Verified ERW at Scale
Overview
UNDO spreads crushed basalt and other silicate rocks on agricultural land across the UK, US, and Australia. The project uses blockchain technology to track carbon removal and ensure transparency, making it one of the most trusted ERW providers in the voluntary carbon market. UNDO’s end-to-end platform—from sourcing rock to monitoring weathering—enables rapid deployment and rigorous verification. In 2025, UNDO became one of four global winners of the $100 million XPRIZE Carbon Removal competition, funded by the Musk Foundation. The company has already enriched over 54,000 acres of farmland, permanently removing roughly 69,000 tons of CO2.
Type: Agricultural Enhanced Rock Weathering (ERW)
Location: UK, US, Australia, with expansion into Brazil
Annual Impact: Targets removal of 1 million tons of CO₂ by 2025, with a long-term goal of 4 billion tons annually
Key Benefits
Climate: Provides durable, high-integrity carbon credits verified by Puro.earth.
Soil Health: Enhances soil fertility, reduces fertilizer use, and improves water retention.
Farmers: Offers farmers a new revenue stream through carbon credit sales.
SDGs: Aligns with SDG 2 (Zero Hunger), SDG 13 (Climate Action), and SDG 15 (Life on Land).
Why It Stands Out
UNDO is a pioneer in combining ERW with blockchain-based MRV, ensuring full traceability and trust in its carbon credits. Its partnership with Microsoft and McLaren Racing highlights its appeal to corporations seeking high-quality removal credits. By sourcing rock from local quarries and focusing on marginal lands, UNDO minimizes environmental impact while maximizing scalability. The project’s recent collaboration with Verde AgriTech in Brazil further demonstrates its ability to adapt to diverse agricultural contexts and feedstocksZeroEx: Precision ERW with Mining By-Products
ZeroEx: Precision Enhanced Rock Weathering with Mining By-Products
Overview
ZeroEx accelerates the weathering of basalt and other silicate rocks by applying finely crushed rock powder to agricultural fields in Germany, Brazil, and beyond. The company uses self-integrating accumulators (SIAs) to measure carbon removal with unprecedented precision, ensuring that every ton of CO2 sequestered is accurately quantified. ZeroEx sources rock powder from mining by-products, reducing costs and environmental footprint. Its Project Earthstone in Brazil, a collaboration with Anglo American, aims to remove up to 15 million tons of CO2 while improving soil health and crop productivity.
Type: Agricultural Enhanced Rock Weathering (ERW)
Location: Germany, Brazil, and expanding to North America
Annual Impact: Expected to deliver 800–1,000 verified carbon removal credits in 2025, with potential for gigaton-scale removal
Key Benefits
Climate: Uses mining waste to create a circular economy for carbon removal.
Agriculture: Substitutes emissions-intensive agricultural lime, reducing farmers’ costs and improving yields.
Innovation: SIAs provide the most accurate and cost-effective MRV method for ERW.
SDGs: Aligns with SDG 9 (Industry, Innovation, and Infrastructure), SDG 12 (Responsible Consumption), and SDG 13 (Climate Action).
Why It Stands Out
ZeroEx is revolutionizing ERW with its cutting-edge MRV technology, which directly measures weathering products in the field. By focusing on local deployments—with rock sourced within 30 km of farms—the project minimizes transport emissions and supports regional economies. Its partnership with Isometric and Anglo American positions ZeroEx at the forefront of high-integrity carbon credit generation. The company’s ability to transform mining by-products into valuable feedstocks for carbon removal makes it a model for sustainable industrial collaboration.
How to Choose the Right ERW Carbon Credit for Your Business
When selecting ERW carbon credits, prioritize permanence by choosing projects with verified geological storage, such as basalt mineralization or coastal bicarbonate formation. Consider co-benefits that align with your goals—whether it’s soil health, ocean restoration, or community empowerment.
Budget matters: prices range from $50 to $450 per ton, so balance cost with quality. Look for third-party verification (e.g., Puro.earth, Isometric) and scalability, favoring projects with strong partnerships and transparent MRV (Measurement, Reporting, and Verification). Avoid vague claims and prioritize projects with clear additionality and expansion plans.
The Future of ERW: Trends to Watch in 2025–2030
The ERW market is set to grow rapidly, driven by policy support (e.g., EU’s CRCF, US funding) and technological advances like AI-driven MRV and automated deployment. Demand for scalable, permanent carbon removal will rise as corporations seek high-integrity credits.
By 2030, ERW could remove billions of tons of CO2 annually, with innovations like hybrid ERW-DAC systems and expanded applications in agriculture and coastal environments. Early adopters will benefit from securing credits from leading projects as the market matures.
Conclusion
Enhanced Rock Weathering is more than just a carbon removal technology—it’s a scalable, permanent, and multifunctional solution for addressing climate change while delivering tangible co-benefits for soil, water, and communities. The five projects highlighted—Project Vesta, Eion, Carbfix, UNDO, and ZeroEx—represent the cutting edge of ERW in 2025, each offering unique strengths in verification, scalability, and impact.
For businesses, investing in ERW credits means supporting long-term carbon removal while aligning with broader sustainability goals, from regenerative agriculture to ocean health. As the market evolves, ERW is poised to play a critical role in global decarbonization efforts, backed by advancing technology, supportive policies, and growing corporate demand.
Ready to take the next step? Whether you're looking to offset emissions, enhance your sustainability strategy, or explore high-integrity carbon projects, expert guidance can help you make the right choices. Contact Regreener today to speak with our team and start your journey toward meaningful climate impact.
