esg-vocab

A framework-neutral semantic vocabulary for ESG data.

Persistent URI namespace: https://w3id.org/esg/
Publisher: JustSemantics
License: CC BY 4.0

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Problem

Every major ESG reporting framework (CSRD, ESRS, GRI, TCFD, CDP, SFDR, EU Taxonomy) defines its own disclosure schema. None share machine-readable identifiers. A "Scope 2 market-based emission" in ESRS E1-6 and a "GRI 305-2 market-based" figure are the same concept — but no machine knows that. Every compliance tool re-implements the mapping from scratch, incorrectly, in a spreadsheet.

This vocabulary is the missing semantic layer.

What this is

• Core ontology (ontology/esg-core.ttl) — OWL classes for ESG domains, emission scopes (GHG Protocol Scope 1/2/3 + all 15 Scope 3 categories), ESG indicators, reporting frameworks, and unit bindings
• QUDT unit bindings — tCO2e, kWh, MWh, GJ, m³, t — resolving the free-text unit problem at the vocabulary layer
• Wikidata alignment — owl:sameAs links to Wikidata entities throughout
• Crosswalk modules (crosswalks/) — SSSOM-serialised mappings between frameworks, with confidence scores and boundary notes per mapping

Crosswalks (v0.1)

File	Coverage
crosswalks/esrs-e1-gri-305.ttl	ESRS E1-6 ↔ GRI 305 (Scope 1, 2 LB, 2 MB, 3)

Planned: ESRS ↔ TCFD, ESRS ↔ CDP, GRI ↔ EU Taxonomy, SFDR PAIs ↔ ESRS datapoints.

Design principles

1. Framework-neutral core — esg-c: concepts exist independently of any reporting standard. Frameworks are modelled as esg-c:ReportingFramework instances.
2. Crosswalk-first — the mapping logic between frameworks is a first-class artefact, not a footnote. Each crosswalk has its own resolvable URI and version.
3. QUDT over free text — every indicator binds to a qudt:Unit. No custom unit strings. No "Ein Liter Heizöl".
4. SSSOM for mappings — machine-actionable mapping provenance with confidence scores and justification codes per mapping triple.
5. Wikidata-aligned — owl:sameAs to Wikidata entities where they exist, connecting into the broader linked data graph.

Namespace structure

https://w3id.org/esg/          → core vocabulary
https://w3id.org/esg/core/     → core classes and properties
https://w3id.org/esg/esrs/     → ESRS-specific disclosure concepts
https://w3id.org/esg/gri/      → GRI-specific disclosure concepts
https://w3id.org/esg/crosswalk/→ crosswalk mapping sets

Usage

PREFIX esg-c: <https://w3id.org/esg/core/>
PREFIX esrs:  <https://w3id.org/esg/esrs/>
PREFIX gri:   <https://w3id.org/esg/gri/>
PREFIX skos:  <http://www.w3.org/2004/02/skos/core#>

# Find all GRI disclosures that map to an ESRS E1 indicator
SELECT ?esrsIndicator ?griIndicator ?confidence WHERE {
  ?mapping sssom:subject_id ?esrsIndicator ;
           sssom:object_id  ?griIndicator ;
           sssom:confidence ?confidence .
  ?esrsIndicator esg-c:reportedUnder esg-c:ESRS .
  ?griIndicator  esg-c:reportedUnder esg-c:GRI .
}
ORDER BY DESC(?confidence)

Status

v0.1.0 — initial scope taxonomy, unit bindings, framework stubs, first crosswalk.
Not yet stable. Breaking changes possible before v1.0.0.

Contributing

Issues and PRs welcome. Crosswalk contributions especially — if you have domain expertise in TCFD, CDP or SFDR disclosure requirements, open an issue.