Carbon Solution · Geological CDR

Enhanced
Weathering —
Rocks that Eat CO₂

Vivent Carbon spreads finely crushed basalt and olivine on smallholder farmland, accelerating the Earth's natural rock weathering cycle to lock CO₂ into dissolved bicarbonates — permanent, geologically-stable carbon removal with a free boost to soil fertility.

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tCO₂e per tonne of rock applied
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Carbon permanence — geological timescale
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Average crop yield increase at pilot sites
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Active programmes (India, Australia, UK)
What is Enhanced Weathering?

The Same Process That Ended
Ice Ages. Accelerated.

Over geological timescales, the weathering of silicate rocks is the Earth's primary mechanism for drawing down atmospheric CO₂. Rainwater reacts with CO₂ to form carbonic acid, which dissolves silicate minerals in rocks — converting atmospheric carbon into dissolved bicarbonates that eventually reach the ocean and are stored for millions of years. This slow process naturally regulates Earth's climate over millions of years.

Enhanced weathering accelerates this cycle by grinding silicate rocks — primarily basalt and olivine, two of the most reactive and widely available — to fine powders that expose vastly greater surface area to weathering reactions. Spreading this "rock dust" on agricultural land dramatically increases the dissolution rate, removing CO₂ from the atmosphere within years rather than millennia, while delivering the dissolved minerals directly to the root zone where crops benefit from them immediately.

Vivent Carbon operates enhanced weathering programmes in India (Maharashtra and Karnataka) and is co-developing Australia's first large-scale EW programme in the Darling Downs, Queensland, in partnership with basalt quarry operators and cotton farming cooperatives. We also participate in a UK Innovate-funded research programme in Lincolnshire to advance MRV methodology for tropical deployment contexts.

Why enhanced weathering is Vivent's highest-permanence land pathway

Carbon stored as dissolved bicarbonate in groundwater and ocean — geological permanence, no reversal risk
No land use change required — applied to existing active farmland
Basalt is one of the most abundant rocks on Earth — near-zero material scarcity risk
Soil pH correction benefits crops directly — reduces need for agricultural lime
Measurable via multiple independent proxies — soil geochemistry, water chemistry, crop uptake
Compatible with all cropping systems — no practice change required from farmers
Project Metrics
Carbon removal0.3–2.0 tCO₂e/t rock
Permanence class>10,000 years
Rock types usedBasalt · Olivine · Dunite
Application rate10–50 t/ha per application
Typical credit price$120–$350 / tCO₂e
Farmer revenue share≥ 60% + free rock
Crop yield benefit+8–22% (pH correction)
Verification Standards
IsometricEnhanced weathering methodology
Frontier CDRAdvance market commitment
Carbon DirectScientific due diligence partner
UNDO ProtocolEW-specific methodology (UK)
The Science

Geochemistry That
Works With Nature,
Not Against It

When basalt is ground to fine powder (typically <2mm) and spread on agricultural soil, the high surface area of reactive silicate minerals reacts rapidly with carbonic acid (CO₂ dissolved in rainwater). This reaction, called silicate hydrolysis, produces dissolved calcium, magnesium, and silica along with bicarbonate ions (HCO₃⁻).

These bicarbonates leach through the soil with drainage water, entering groundwater and rivers, and ultimately the ocean — where they are stable for millions of years as part of the ocean's alkalinity buffer. The net reaction can be summarised as: CO₂ + silicate rock → HCO₃⁻ (stable in ocean).

The rate at which this reaction occurs depends on rock chemistry, particle size, soil temperature, moisture, and microbial activity. Tropical soils like those in India's Deccan Plateau — warm, moist, and biologically active — weather basalt 5–8× faster than temperate soils, making them among the most efficient enhanced weathering locations on Earth.

Vivent measures carbon removal via three independent proxies: soil geochemistry (depletion of reactive minerals), watershed water chemistry (bicarbonate flux), and crop tissue analysis (uptake of released cations). Convergence of all three gives high confidence in the carbon accounting.

The Weathering Reaction
Step 1 — CO₂ dissolves in rainwater
CO₂ (atm) + H₂O → H₂CO₃ (carbonic acid)
Step 2 — Acid weathers basalt minerals
CaSiO₃ + 2CO₂ + H₂O → Ca²⁺ + 2HCO₃⁻ + SiO₂
Step 3 — Bicarbonate reaches the ocean
HCO₃⁻ leaches to groundwater → rivers → ocean (stable >10,000 yrs)
Net result per tonne of basalt weathered
≈ 0.3–0.4 tCO₂e removed + Ca²⁺/Mg²⁺/Si released to soil (crop benefit)
How Vivent Measures It
01Soil geochemistry — mineral depletion rates measured from core samples pre and post-application
02Watershed water chemistry — bicarbonate and cation flux measured in drainage water
03Crop tissue analysis — calcium and magnesium uptake confirms weathering products entered the food chain
04All three proxies reconciled with geochemical models to produce conservative credit estimate
How It Works

From Quarry to Verified
Geological Carbon Removal

Enhanced weathering is one of the simplest CDR pathways to deploy — the complexity is in the measurement, not the application.

1
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Rock Sourcing & Grinding

Basalt or olivine sourced from quarries within 200km of application sites to minimise transport emissions. Rock ground to fine powder (<2mm particle size) at the quarry. Vivent conducts full lifecycle carbon assessment of mining, grinding, and transport to ensure net negativity.

2
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Soil Baseline Sampling

Stratified soil cores taken at 0–20cm, 20–40cm, and 40–60cm from enrolled plots before first application. Elemental analysis of major cations (Ca, Mg, K, Si) and pH establishes geochemical baseline for quantifying future weathering signal.

3
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Application to Farmland

Rock dust broadcast-spread at 10–50 t/ha using standard farm spreader equipment. Application timed to precede monsoon or irrigation events that initiate weathering. GPS-verified coverage maps generated for every plot. Farmers receive the rock free of charge — it is part of the carbon service.

4
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Drainage Water Monitoring

Automated water samplers installed in drainage channels below treated plots. Alkalinity, bicarbonate, calcium, and magnesium concentrations monitored monthly. The increase in these ions in drainage water directly quantifies the CO₂ that has been converted to stable bicarbonate.

5
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Annual Soil Geochemistry

Annual soil re-sampling tracks the depletion of reactive minerals in the applied rock dust. Progressive depletion of calcium silicates and olivine confirms ongoing weathering reaction — cross-validated with drainage chemistry for double-proxy confidence.

6
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Independent Lab Analysis

All geochemical samples analysed at accredited external laboratories (NABL-certified in India, NATA-certified in Australia). Laboratory blind-testing of 10% of samples cross-validates field measurements. All raw data published on Vivent's open data portal.

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Isometric Verification

Annual submission to Isometric for third-party verification. Isometric's enhanced weathering protocol requires multi-proxy evidence and publishes uncertainty ranges alongside credit issuances — buyers receive central estimate with explicit confidence bounds.

8
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Farmer Revenue

Farmers earn ≥60% of credit revenue (the free rock application itself has significant economic value — saving farmers $40–$120/ha in lime and fertiliser costs annually). Carbon payments arrive within 30 days of credit settlement via mobile banking.

Beyond Carbon

Rocks That Carbon. Rocks
That Also Feed the Farm.

Enhanced weathering is the only CDR pathway where the carbon removal mechanism is the same process that delivers agronomic co-benefits — no tension between carbon and farming goals.

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Crop Yield & Soil pH

Basalt application corrects soil acidification — one of the primary yield limiters in tropical smallholder systems. Field trials show 8–22% yield increases in acidic soils within two seasons of application, equivalent to the effect of agricultural lime but with additional silica and micronutrients.

SDG 2SDG 1
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Counteracts Ocean Acidification

The bicarbonate ions released by weathering ultimately reach the ocean, adding alkalinity that counteracts the pH decline caused by oceanic CO₂ absorption. Every tonne of basalt weathered contributes measurably to restoring ocean chemistry to safer ranges for marine life.

SDG 14SDG 13
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Soil Microbial Diversity

Released silicon, calcium, and magnesium from weathering basalt support a more diverse soil microbial community — silica-cycling bacteria in particular show 3–5× abundance increases in treated plots, with cascading benefits for organic matter decomposition and nutrient cycling.

SDG 15
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Lime & Fertiliser Replacement

Agricultural lime (calcium carbonate) costs Indian farmers $30–$80/ha per application cycle. Basalt application delivers equivalent pH correction plus additional silicon and magnesium at no cost to the farmer under Vivent's model — saving $40–$120/ha annually in input costs.

SDG 1SDG 8
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Drought Resilience

Silicon released by basalt weathering is taken up by plants and deposited in cell walls as phytoliths — strengthening drought tolerance and pest resistance. Silicon-sufficient crops show 20–35% improved water use efficiency during dry periods in Vivent's monitored trial plots.

SDG 13SDG 2
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Industrial Symbiosis

Basalt is a by-product of quarrying and construction aggregate operations. Vivent's partnerships with quarry operators create a high-value use for fine crushed material that is otherwise a low-value waste stream — creating economic incentive for quarry operators to participate.

SDG 12SDG 9
Where We Work

Three Countries, Three Climates,
One Geochemical Principle

Tropical soils weather basalt 5–8× faster than temperate soils — Vivent prioritises warm, wet deployment zones for maximum carbon removal efficiency.

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India — Maharashtra & Karnataka

Basalt is native to the Deccan Plateau — India's volcanic geology means quarry partners are within 50–100km of farm deployment sites. Soybean, cotton, and sorghum farms across Nashik, Osmanabad, and Bidar districts. India's warm, humid monsoon climate delivers among the highest weathering rates globally.

1,800Farmer households
9,200 haUnder application
IsometricRegistry
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Australia — Darling Downs, QLD

Co-development programme with Darling Downs cotton and grain cooperative. Basalt sourced from Queensland's Main Range volcanic formation. Humid subtropical climate delivers year-round weathering. Partnership with University of Queensland for soil geochemistry MRV. First credit issuance targeted for 2026.

340Farm enterprises
18,000 haTarget area
Isometric/UNDORegistry (pending)
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United Kingdom — Lincolnshire (R&D)

Research partner in UKRI-funded UNDO and Leverhulme-supported enhanced weathering trials on arable farmland in the Fens. Vivent's role is contributing tropical MRV methodology development — the temperate UK site generates MRV protocol learnings applicable to our India and Australia programmes.

R&DRole
4 sitesTrial plots
UNDO ProtocolFramework
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Field ReportMaharashtra, IndiaSeason 3 Results

Maharashtra Basalt Trial: 0.38 tCO₂e/t Rock, 17% Soybean Yield Gain, Three-Proxy Verified

Vivent's Maharashtra enhanced weathering programme enrolled 1,200 soybean and cotton farmers across Nashik and Osmanabad districts in 2022, applying basalt powder sourced from three local quarries at rates of 25–40 t/ha. The programme is notable for deploying all three MRV proxies simultaneously from Year 1 — soil geochemistry, drainage water chemistry, and crop tissue analysis — establishing the most comprehensive EW dataset from a tropical smallholder context to date.

Season 3 independent verification by Isometric confirmed a net carbon removal rate of 0.38 tCO₂e per tonne of basalt applied — at the conservative end of the theoretical range, validating Vivent's cautious accounting approach. Soybean yields on treated plots improved by 17% versus control plots, attributed to pH correction and silicon supplementation. Average farmer benefit including carbon income and lime cost savings reached ₹22,800 ($272) per hectare in Year 3.

0.38t
tCO₂e per tonne basalt — Isometric verified
+17%
Soybean yield vs control plots, Season 3
₹22.8K
Combined farmer benefit per hectare, Year 3
Read Full Case Study →
Common Questions

Enhanced Weathering — FAQ

Once CO₂ is converted to dissolved bicarbonate (HCO₃⁻) in groundwater and ocean water, it is thermodynamically stable at ocean pH and temperature — it does not re-convert to CO₂ and outgas on any timescale relevant to human concerns. The ocean's alkalinity buffer has maintained dissolved inorganic carbon for millions of years. Independent geochemical modelling confirms >99% of weathered bicarbonate remains dissolved in the ocean for >10,000 years. This is why enhanced weathering is classified as "geological permanence" — the highest durability class in the carbon market.
Yes — mining, grinding, and transporting rock dust all require energy and emit CO₂. Vivent conducts full lifecycle assessment (LCA) per project and only issues credits for the net removal after subtracting all process emissions. Typical net removal is 0.30–0.38 tCO₂e per tonne of rock applied for basalt in India (gross removal ~0.42t, minus ~0.06t LCA emissions for local sourcing). We publish full LCA reports for every project — buyers can inspect the methodology. Transport distance is a key variable, which is why Vivent only works within 200km of quarry sources.
Basalt and olivine contain trace heavy metals (chromium, nickel, cobalt) at naturally occurring concentrations. Independent soil scientists and ecotoxicologists have reviewed application rates comparable to those used in Vivent's programmes and found no evidence of heavy metal accumulation in soil or crops at agronomic application rates. All rock sources used by Vivent are geochemically screened before approval, and annual soil monitoring tracks heavy metal levels in all enrolled plots. Our rock screening standards meet or exceed those used by Isometric and Carbon Direct in their due diligence frameworks.
Enhanced weathering credits ($120–$350/tCO₂e) command premium pricing for two reasons: permanence and removal type. EW delivers >10,000-year geological permanence with zero reversal risk — the highest durability class available at scale. And it is genuine carbon dioxide removal from the atmosphere, not an avoided emission. The measurement infrastructure (lab analysis, water monitoring, geochemical modelling) is also more expensive than forestry MRV. For buyers operating under SBTi, Oxford Principles, or ICVCM requirements for high-durability removal, EW credits are among the most suitable available.
The theoretical potential of enhanced weathering at global scale is enormous — estimates range from 0.5 to 4 GtCO₂/year if deployed across suitable agricultural land globally. The binding constraints are measurement infrastructure (MRV at scale), quarry proximity, and logistics — not geology or chemistry. Vivent's India programme demonstrates that smallholder-scale deployment is operationally feasible today. We expect EW to follow a similar cost and scale trajectory to solar PV — initially high-cost and small-scale, but with rapid learning curve benefits as deployment scales through the 2030s.
Ready to Act?

The Most Permanent Carbon
Removal on the Market.

Vivent's enhanced weathering credits are Isometric-verified, three-proxy measured, and geologically permanent. For buyers who need durability they can defend, this is it.