The Problem

Carbon data is everywhere.
None of it speaks the same language.

“Platforms use different units, methods, scopes, and emission factor vintages. Without a shared vocabulary, you cannot compare, verify, or trade carbon data.”

Every company measures carbon differently. Every platform stores it differently. Every regulator asks for it differently. The result is a fragmented landscape where carbon data cannot be trusted, compared, or acted upon at scale. COMET resolves this by providing the shared vocabulary the market is missing.

What COMET Does

One ontology. Every standard. Every sector.

01

Shared Vocabulary

One ontology maps ISO 14067, PACT v3, GHG Protocol, CBAM, and EAC standards into interoperable classes that any platform can consume.

02

Seven-Layer Stack

From core identity primitives (L1) to market pricing signals (L7), each layer is independently versionable and composable with the rest.

03

Community Governed

Steering Committee, Technical Committee, and open Working Groups. All decisions made via public GitHub with full audit trails.

Who Benefits

Built for everyone who touches carbon data.

Industrial Buyers

Equal-footing supplier comparison

Compare supplier PCFs on equal footing. Auto-generate CBAM declarations from structured, verified data.

Carbon Verifiers

Machine-readable claims

Issue machine-readable verification claims. Replace static PDFs with trusted, queryable data objects.

Platform Vendors

Instant interoperability

npm install @comet/ontology — instant interoperability with any COMET-compliant platform.

Regulators

Proven open standard

Reference a proven open standard for CBAM, CSRD, and IRA 45V compliance frameworks.

LCA Practitioners

Universal export format

Export SimaPro and openLCA results in a universal format any downstream system can read without translation.

Financial Markets

Product-level carbon risk

Price carbon risk using verified, product-level data rather than sector averages and disclosure estimates.

Deep Dive

50 quantified use cases across 10 stakeholder groups

Interactive Sankey diagrams, sourced savings metrics, and a “My Use Case” builder that maps your data onto COMET layers.

Explore Stakeholder Benefits →

The Forcing Function

CBAM is live. The cascade is underway.

Now

CBAM Full Enforcement · Jan 2026

Approximately 4,000 EU importers now require structured carbon data from roughly 40,000 direct suppliers — and hundreds of thousands of sub-suppliers cascading further up each value chain. This is not a reporting exercise. It is a data infrastructure problem that is happening right now. COMET is the shared language this cascade requires.

Standards Integration

One vocabulary. Every carbon data standard.

COMET provides the semantic middleware between data producers and consumers. Supply chain platforms, LCA tools, and registries produce data in proprietary formats. COMET’s JSON-LD context injection maps any payload into a shared ontology — so buyers, verifiers, regulators, and carbon markets can consume standardized, machine-readable data without translation.

WBCSD PACT v3

Complete field-by-field mapping

Every PACT v3 ProductFootprint and CarbonFootprint field maps to a COMET class via owl:equivalentClass and owl:equivalentProperty triples. Drop-in JSON-LD @context upgrades any PACT payload to semantic RDF.

EU CBAM

Declaration structure in XML & JSON

CBAM embedded emissions declarations (Reg. 2023/956) mapped to COMET classes with working XML, XSD schema fragments, and CN code coverage for steel, aluminium, cement, hydrogen, and chemicals.

CAD Trust v2.0.2

Full registry interoperability

All 13 CAD Trust tables (project, unit, verification, issuance, label, co-benefit, Article 6 ITMO) mapped into COMET namespaces. 100+ variables aligned for carbon credit registry data exchange.

GHG Protocol & ISO 14067

Scope 3 and product-level coverage

GHG Protocol Scope 3 Categories 1–15 mapped to COMET supply chain and PCF classes. ISO 14067 Section 7 required elements fully covered in L4 PCF layer.

Data Tools

Convert, validate, and export — today.

COMET ships with a complete, open-source data toolchain so you can start working with COMET-compliant data immediately. Every tool runs locally (Python CLI) or in your browser (Playground) — no accounts, no API keys, no vendor lock-in.

Ingest

4 Format Converters

Convert CSV spreadsheets, PACT v3 JSON, CBAM XML declarations, and CAD Trust registry data into COMET JSON-LD with a single command. Field-level mappings cover 44 PACT fields, all CBAM CN codes, and 13 CAD Trust tables.

Validate

JSON Schemas + CLI

Three JSON Schemas (PCF, EAC, Core) validate any COMET document against the ontology. The comet validate CLI gives structured errors with fix suggestions. Batch mode validates entire directories.

Export

3 Egress Formats

Export COMET data back to PACT v3 for WBCSD exchange, CBAM XML for EU regulatory filing, or flat CSV for spreadsheet workflows. Round-trip fidelity ensures nothing is lost in translation.

Browser

Data Playground →

Paste or upload data in any supported format and instantly convert, validate, and download COMET JSON-LD — entirely in your browser. No install required. Try it with the built-in steel, aluminium, and DAC credit examples.

CLI + Python

Command-Line Toolkit

pip install jsonschema
python comet_cli.py validate my-pcf.json
python comet_cli.py convert data.csv --from csv --to comet CSV templates, 6 worked examples (steel, aluminium, DAC credits, PACT, CBAM, CAD Trust), and full documentation included.

Documentation

Everything you need to build with COMET.

Visual Reference — 20 Data Visualizations

Visual Guide

20 MECE visualizations: seven-layer stack, standards heatmap, PACT/CBAM/CAD Trust mappings, data quality radar, contribution workflow, regulatory timeline, and market signals.

Getting Started — 8 Stakeholder Guides

How To Use COMET

Eight concrete examples showing buyers, supply chain managers, LCA practitioners, verifiers, platforms, regulators, financial markets, and credit developers how COMET solves their specific problems.

Interactive — 50 Quantified Use Cases

Stakeholder Benefits & Use Case Builder

10 stakeholders × 5 use cases with Sankey diagrams, quantified savings, and an interactive “My Use Case” builder that maps your data onto COMET layers.

Technical Specification

Data Exchange & Transport Layer

Field-by-field mappings for PACT v3, EU CBAM, and CAD Trust with working code examples in JSON-LD, XML, XSD, JSON Schema, and OWL Turtle.

Reference Dictionary — Interactive Search

Glossary & Data Dictionary

Complete class, property, and variable reference for all 7 COMET layers plus CAD Trust v2.0.2. Interactive search with layer filters and A–Z jump bar.

Interactive Tool — Browser-Based

Data Playground

Paste or upload CSV, PACT v3, CBAM XML, or CAD Trust data and instantly convert to COMET JSON-LD. Validate, preview, and download — no install required.

Reference Specification

Ontology Specification

The complete COMET ontology: 7-layer architecture and 20 visualization sections covering stakeholders, maturity model, namespace architecture, standards alignment, governance, and more.

Implementation Roadmap

Master Build Plan

200 expert steps across 10 MECE panels, sequenced into a 36-month roadmap from foundations to v1.0 stable. Assigned owners, dependencies, and success criteria for every step.

Presentation — Download PPTX

Stakeholder Deck

30-slide presentation covering the problem, architecture, stakeholder benefits, governance model, and roadmap. Ready for board, investor, and regulatory audiences.

Roadmap

From foundations to global infrastructure.

Phase 1 · Complete

Q1–Q2 2025

Foundations & First Adopters

  • Core ontology & 7-layer stack
  • PACT v3 full alignment (44 fields)
  • JSON Schema validation
  • CBAM declaration class
  • Data toolchain (CLI, converters, playground)

Phase 2 · Current

Q3 2025 – Q1 2026

Supply Chain & Verification

  • Full supply chain module
  • CAD Trust verification layer
  • EAC hierarchy & registry interop
  • Verification connector pilots

Phase 3

Q2 2026 – Q4 2026

Market Layer & Sectors

  • Pricing signals layer (L7)
  • Steel / H2 / Chemicals / Aluminium WGs
  • CSRD mapping
  • v1.0 stable release

Phase 4

Q1 2027 – Q4 2027

Global Scale & Nature

  • Real-time IoT streaming
  • TNFD biodiversity layer
  • Tokenized EAC rails
  • AI query interface

Partner With Us

Build the carbon data infrastructure the world needs.

COMET is an open standard — but adoption requires collaboration. We are seeking founding partners from industry, platforms, verifiers, and regulators to shape the ontology, pilot integrations, and join the governance structure.

Industry

Steel, aluminium, chemicals, and cement producers piloting COMET for CBAM compliance and supply chain data exchange.

Platforms

Carbon accounting, LCA software, and supply chain platforms integrating COMET as a data exchange layer.

Verifiers

Assurance firms issuing machine-readable verification claims that flow through the COMET network.

Regulators

Policy bodies referencing COMET for CBAM, CSRD, IRA 45V, and voluntary carbon market compliance frameworks.

Get in touch →

ng@carbonsig.com  ·  Nick Gogerty  ·  Carbon Finance Lab