Puro.earth Overview
Puro.earth is an engineered carbon dioxide removal (CDR) standard, registry, and market-infrastructure company based in Helsinki (Puro.earth Oy). It does not operate as a conventional multi-sector offset registry: CORCs are framed exclusively as durable removals, with avoidance kept out of CORC accounting.
This note is the map of the Puro cluster in the vault. Open child notes for depth; do not treat this overview as a substitute for the methodology or MRV chapters.
Why it matters for biochar
Biochar carbon removal (BCR) has been one of Puro’s longest-running pathways. Under Puro Biochar Methodology Edition 2025, biochar CORCs are labelled CORC200+ (“several centuries,” ≥200 years), with public price discovery via Nasdaq × Puro CORCX indexes. For a US producer choosing among registries, start here, then read Puro vs Other Standards and Puro Project Cycle and MRV.
Related vault concepts: Biochar as Durable CDR · Permanence Science for Credits · MRV Stack · Market Hub · Market Volumes and Pricing · Buyers and Offtakes · Historical Deals · Price Indexes and Benchmarks · Risks and Controversies
Company and registry history
| Date | Event | Source |
|---|---|---|
| Mar–May 2019 | Original Signatories (22 orgs across 6 countries) design the Puro Standard + first methodologies in ~71 days | Puro Standard page; half-decade post |
| Apr–May 2019 | Fortum internal startup “Puro” launches marketplace pilot; first CORCs auctioned 24 May 2019 (biochar, carbonated materials, wooden building elements) | Fortum 2019; half-decade post |
| 1 Jun 2021 | Nasdaq acquires majority stake from Fortum; Puro remains an independent company/brand; Nasdaq × Puro CORC indexes follow | Nasdaq IR; Fortum |
| Oct 2021 | Independent external Advisory Board appointed to house the Puro Standard | Puro Standard page |
| 11 Dec 2025 | ICVCM confirms Puro.earth as CCP-Eligible program for General Rules v4.2+ (methodologies not yet CCP-Approved as of that announcement) | ICVCM |
Legal entity: Puro.earth Oy (Helsinki).
Role: engineered-CDR standard + Nasdaq-powered Puro Registry + market infrastructure.
What a CORC is
A CO₂ Removal Certificate (CORC) = 1 metric tonne CO₂e net removal, independently verified under a Puro methodology, recorded in the Puro Registry, transferable, and retired when applied to a climate claim (CORC page).
General marketing still frames “100+ year durability” as the baseline CORC definition across pathways. Biochar Edition 2025 specifically issues CORC200+.
Durability label ladder (biochar)
| Label | Biochar methodology | Permanence framing | Decay basis |
|---|---|---|---|
| Early (Edition 2019) | Spokas 2010 O:C framing | 100-year style | Spokas |
| CORC100+ | Edition 2022 | ~100 years | models soil GHG from biochar multi-pool exponential; H/C_org + soil T |
| CORC200+ | Edition 2025 (v1 Jun 2025; v2 Nov 2025) | Several centuries (≥200 years; EU “permanent removal” alignment cited) | Revised power-law decay; H/C_org + soil T; 80% CI lower bound; open-source notebook |
Source: Puro permanence explainer, 2025-07-03; Edition 2025 v2 methodology §1.1, §6.2.
Science context: Permanence · Permanence Science for Credits · Woolf et al. 2021 (DOI)
Positioning claims (Puro, retrieved 2026-09-14)
Puro’s public positioning (treat as marketing claims, verify against registry counters for live scale):
- Focus exclusively on durable carbon removal (no mixing avoidance into CORC accounting)
- Durability labels: 100+ / 200+ / 1,000+ years depending on methodology
- Marketing stats cited in research: 74% share of delivered CDR (Puro claim); 600+ buyers; 8 methodologies; >100 certified engineered CDR projects; >1.5M CORCs issued historically
- Live registry counters (2026-09-14 fetch): ~1.88M issued / ~1.08M retired / 119 certified projects (registry.puro.earth)
- Biochar: 70+ projects certified since 2019 (permanence post)
Registry scale snapshot (2026-09-14)
| Metric | Value | Source |
|---|---|---|
| Issued CORCs (all methods) | ~1.88M | registry.puro.earth |
| Retired CORCs | ~1.08M | registry |
| Certified projects | 119 | registry |
| Biochar projects since 2019 | 70+ | permanence post |
| Delivered CDR market share (Puro claim) | 74% | CORC page |
Integrity status (ICVCM)
| Layer | Status (as of research date 2026-09-14) |
|---|---|
| Program | CCP-Eligible for facilities under General Rules v4.2+ (ICVCM 2025-12-11) |
| Biochar methodology | Not yet CCP-Approved — must pass separate ICVCM category assessment for CCP credit labels |
Practical implication: buyers who require a CCP-labelled methodology today may prefer Verra VM0044 (VM0044 v1.2 CCP-Approved 2025-07-24) until Puro’s biochar category assessment completes. Program eligibility alone is not a CCP credit label. See Puro vs Other Standards · Risks and Controversies.
How Puro fits the CDR / BCR market
- Removal-only product. CORCs are engineered-CDR certificates; they are not a general-purpose offset unit mixing avoidance and removal.
- Ex-post issuance after use. For biochar, the point of CORC creation is the first durable eligible use, not the factory gate alone — see Puro Project Cycle and MRV.
- Public price signal. Unlike most BCR pathways, Puro publishes Nasdaq-methodology indexes (CORCX, CORCCHAR) — see Puro Pricing and CORC Indexes · Market Volumes and Pricing.
- Buyer recognition. Early Microsoft CORC procurements and CDR.fyi BCR Snapshot 2025 buyer lists (Microsoft, Google, BCG, JPMorgan, Swiss Re, SEB with explicit Puro/CORC narrative) place Puro among the most recognizable BCR venues — see Buyers and Offtakes.
- Liquidity trend. CDR.fyi (citing Puro Aug 2025 report): biochar CORC issuance→transfer/retirement time improved from 95 days (2021) to 22 days (mid-2025).
Broader framing: Biochar as Durable CDR · Carbon Markets Hub
Architectural difference vs other standards (summary)
| Dimension | Puro | Verra VM0044 | Isometric | CSI Global Biochar C-Sink |
|---|---|---|---|---|
| Scope | Engineered CDR only; multi-pathway standard | Broad VCS; biochar is one method | CDR-focused registry + protocol modules | Product + C-sink standard (EBC/WBC prerequisite) |
| Biochar unit | CORC200+ (Ed. 2025) | VCU removals | Net CO₂e removal credits | GPC / SPC C-sinks |
| Horizon | Several centuries (200+) | 100 years | 200y or 1000y (Ro path) | GPC >1000y / SPC ≤1000y |
| Price signal | Public CORCCHAR / CORCX (Nasdaq) | No equivalent public biochar index | Private / deal-based | Deal-based |
| ICVCM (research date) | Program CCP-Eligible; biochar method not yet CCP-Approved | VM0044 v1.2 CCP-Approved | Program CCP-Eligible | Submitted / in process |
Full comparison, chooser table, and critique watch-list: Puro vs Other Standards
Peer notes: Verra VM0044 · Isometric Biochar Protocol · CSI Global Biochar C-Sink
Puro deep-dive cluster (link map)
Open these as standalone chapters:
| Note | What you get |
|---|---|
| Puro CORC200+ | Durable-credit concept: what CORC200+ means, label history, permanence claim, transition milestones — without duplicating full method text |
| Puro Biochar Methodology Edition 2025 | Exhaustive Edition 2022→2025 evolution, eligibility, feedstock, end uses, LCA, permanence equations, phase-out dates |
| Puro Project Cycle and MRV | Listing → production → application → audit → issuance → retirement; lab metrics; CoC; auditors; US producer path and pitfalls |
| Puro Pricing and CORC Indexes | CORCCHAR/CORCX levels, fee model, deal structures, buyer/volume notes from the report |
| Puro vs Other Standards | Detailed comparison vs Verra / Isometric / CSI and when to choose which |
Cross-links into the rest of the vault
Concepts: Biochar as Durable CDR · Permanence Science for Credits · MRV Stack · Double Counting and Credit Ownership
Market: Market Hub · Market Volumes and Pricing · Buyers and Offtakes · Historical Deals · Price Indexes and Benchmarks · Supply Landscape · Durable CDR Quality Tiers · Risks and Controversies
US ag: NRCS soil carbon amendment in US ag (practice standard — not a credit methodology)
Science: Permanence · Properties · Production · Contaminants and Quality · CDR Potential and IPCC Accounting · Science Hub
Hubs: Carbon Markets Hub · Biochar Home · Key Sources
Critiques and open issues (high level)
From the deep-dive research (detail in Risks and Controversies · Puro vs Other Standards):
- Permanence science divergence — decay-model camp (CORC200+, Isometric 200y, IPCC/Woolf) vs inertinite/Ro millennial camp (Sanei et al.; Isometric 1000y; CSI upper class). Puro stopped at centuries, not millennia, pending further integration (permanence post).
- ICVCM two-tick gap — program eligible, biochar methodology not yet CCP-Approved.
- Edition 2022 → 2025 transition — hard stop 12 Jun 2030; Preliminary Assessments do not transfer.
- No default buffer — eligibility + supplier liability instead of a pooled % buffer.
- Retail / diffuse channels — higher reversal risk even after R3 v2 safeguards.
- Concentration / delivery risk — BCR market buyer and supplier concentration (CDR.fyi); contracted vs delivered gaps.
Primary URLs
- Puro Standard overview
- CORC page
- Registry
- Document library
- Edition 2025 v2 methodology PDF
- Transition plan PDF
- Permanence science
- CORC indexes
- Fees / supplier journey
- ICVCM program CCP-Eligible
- Nasdaq majority stake
- Persistence model repo — https://github.com/puro-earth/PuroBiocharPersistenceEdition2025
Full bibliography for this cluster: Key Sources
Honesty box
- Fees, index levels, and ICVCM methodology-category status change — re-pull before investment or offtake decisions.
- Large offtake registry attribution (e.g., Exomad, Liferaft) should be verified on project pages before citing as “Puro-only.”
- Exact Table 3.2 eligibility rows beyond those extracted in Puro Biochar Methodology Edition 2025 should be read from the official PDF for project design.
- Not legal, accounting, or eligibility advice.
See also
Puro CORC200+ · Puro Biochar Methodology Edition 2025 · Puro Project Cycle and MRV · Puro Pricing and CORC Indexes · Puro vs Other Standards · Carbon Markets Hub · Biochar as Durable CDR · Permanence Science for Credits · MRV Stack · Verra VM0044 · Isometric Biochar Protocol · CSI Global Biochar C-Sink · Market Hub · Market Volumes and Pricing · Buyers and Offtakes · Historical Deals · Price Indexes and Benchmarks · Supply Landscape · Durable CDR Quality Tiers · Risks and Controversies · Permanence · Key Sources