Ontology-Guided Query Expansion for Evidence Retrieval in ESRS E1 Climate Disclosures

Tatsuya Ishisaka


Abstract
Auditable analysis of corporate climate disclosures requires retrieving, for each regulatory disclosure requirement, the report page or section that contains the evidence. We study ontology-aware query expansion (OAE) for ESRS E1 (Climate Change) requirements over a new page/section-level benchmark: five companies, 1,177 real-artifact chunks, and 114 human-reviewed gold labels, plus a held-out ESRS-native company (64 labels) unseen during ontology construction. Against lexical, dense, hybrid, and pseudo-relevance-feedback (PRF) baselines, a lightweight ontology built from the standard’s requirements improves retrieval: the best configuration reaches Recall@10 0.842 vs. BM25’s 0.702 (McNemar p=.003). Generic PRF expansion hurts retrieval while ontology-guided expansion helps; a corpus-blind LLM query expander is a far stronger control and ties with the ontology in-domain, but does not transfer to the held-out company, where OAE stays ahead of lexical, dense, and LLM-expansion baselines while being statistically indistinguishable from cross-encoder reranking — a comparison we treat as diagnostic rather than conclusive. We provide an error analysis of the residual misses. "Gold" denotes retrieval ground truth only; we make no company scoring or compliance judgement.
Anthology ID:
2026.climatenlp-1.8
Volume:
Proceedings of the 3rd Workshop on Natural Language Processing Meets Climate Change (ClimateNLP 2026)
Month:
October
Year:
2026
Address:
Budapest, Hungary
Editors:
Tobias Schimanski, Aida Usmanova, Gaku Morio, Jingwei Ni, Kalyan Dutia, Seyed Saeid Vaghefi, Dominik Stammbach, Markus Leippold
Venues:
ClimateNLP | WS
SIG:
Publisher:
Association for Computational Linguistics
Note:
Pages:
116–123
Language:
URL:
https://aclanthology.org/2026.climatenlp-1.8/
DOI:
Bibkey:
Cite (ACL):
Tatsuya Ishisaka. 2026. Ontology-Guided Query Expansion for Evidence Retrieval in ESRS E1 Climate Disclosures. In Proceedings of the 3rd Workshop on Natural Language Processing Meets Climate Change (ClimateNLP 2026), pages 116–123, Budapest, Hungary. Association for Computational Linguistics.
Cite (Informal):
Ontology-Guided Query Expansion for Evidence Retrieval in ESRS E1 Climate Disclosures (Ishisaka, ClimateNLP 2026)
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PDF:
https://aclanthology.org/2026.climatenlp-1.8.pdf