ClimateCheck 2026: Scientific Fact-Checking and Disinformation Narrative Classification of Climate-related Claims

Raia Abu Ahmad, Max Upravitelev, Aida Usmanova, Veronika Solopova, Georg Rehm


Abstract
Automatically verifying climate-related claims against scientific literature is a challenging task, complicated by the specialised nature of scholarly evidence and the diversity of rhetorical strategies underlying climate disinformation. ClimateCheck 2026 is the second iteration of a shared task addressing this challenge, expanding on the 2025 edition with tripled training data and a new disinformation narrative classification task. Running from January to February 2026 on the CodaBench platform, the competition attracted 20 registered participants and 8 leaderboard submissions, with systems combining dense retrieval pipelines, cross-encoder ensembles, and large language models with structured hierarchical reasoning. In addition to standard evaluation metrics (Recall@K and Binary Preference), we adapt an automated framework to assess retrieval quality under incomplete annotations, exposing systematic biases in how conventional metrics rank systems. A cross-task analysis further reveals that not all climate disinformation is equally verifiable, potentially implicating how future fact-checking systems should be designed.
Anthology ID:
2026.nslp-1.6
Volume:
Proceedings of Natural Scientific Language Processing (NSLP) @ LREC 2026
Month:
May
Year:
2026
Address:
Palma, Mallorca (Spain)
Editors:
Georg Rehm, Stefan Dietze, Danilo Dessi, Diana Maynard, Sonja Schimmler
Venues:
NSLP | WS
SIG:
Publisher:
ELRA Language Resources Association (ELRA)
Note:
Pages:
49–65
Language:
External URL:
https://lrec.elra.info/lrec2026-ws-nslp-06
DOI:
10.63317/3chh989hkiop
Bibkey:
Cite (ACL):
Raia Abu Ahmad, Max Upravitelev, Aida Usmanova, Veronika Solopova, and Georg Rehm. 2026. ClimateCheck 2026: Scientific Fact-Checking and Disinformation Narrative Classification of Climate-related Claims. In Proceedings of Natural Scientific Language Processing (NSLP) @ LREC 2026, pages 49–65, Palma, Mallorca (Spain). ELRA Language Resources Association (ELRA).
Cite (Informal):
ClimateCheck 2026: Scientific Fact-Checking and Disinformation Narrative Classification of Climate-related Claims (Abu Ahmad et al., NSLP 2026)
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