Can Reasoning LLMs Synthesize Complex Climate Statements?

Yucheng Lu


Abstract
Accurately synthesizing climate evidence into concise statements is crucial for policy making and fostering public trust in climate science. Recent advancements in Large Language Models (LLMs), particularly the emergence of reasoning-optimized variants, which excel at mathematical and logical tasks, present a promising yet untested opportunity for scientific evidence synthesis. We evaluate state-of-the-art reasoning LLMs on two key tasks: (1) *contextual confidence classification*, assigning appropriate confidence levels to climate statements based on evidence, and (2) *factual summarization of climate evidence*, generating concise summaries evaluated for coherence, faithfulness, and similarity to expert-written versions. Using a novel dataset of 612 structured examples constructed from the Sixth Assessment Report (AR6) of the Intergovernmental Panel on Climate Change (IPCC), we find reasoning LLMs outperform general-purpose models in confidence classification by 8 percentage points in accuracy and macro-F1 scores. However, for summarization tasks, performance differences between model types are mixed. Our findings demonstrate that reasoning LLMs show promise as auxiliary tools for confidence assessment in climate evidence synthesis, while highlighting significant limitations in their direct application to climate evidence summarization. This work establishes a foundation for future research on the targeted integration of LLMs into scientific assessment workflows.
Anthology ID:
2025.climatenlp-1.21
Volume:
Proceedings of the 2nd Workshop on Natural Language Processing Meets Climate Change (ClimateNLP 2025)
Month:
July
Year:
2025
Address:
Bangkok, Thailand
Editors:
Kalyan Dutia, Peter Henderson, Markus Leippold, Christoper Manning, Gaku Morio, Veruska Muccione, Jingwei Ni, Tobias Schimanski, Dominik Stammbach, Alok Singh, Alba (Ruiran) Su, Saeid A. Vaghefi
Venues:
ClimateNLP | WS
SIG:
Publisher:
Association for Computational Linguistics
Note:
Pages:
288–303
Language:
URL:
https://preview.aclanthology.org/landing_page/2025.climatenlp-1.21/
DOI:
Bibkey:
Cite (ACL):
Yucheng Lu. 2025. Can Reasoning LLMs Synthesize Complex Climate Statements?. In Proceedings of the 2nd Workshop on Natural Language Processing Meets Climate Change (ClimateNLP 2025), pages 288–303, Bangkok, Thailand. Association for Computational Linguistics.
Cite (Informal):
Can Reasoning LLMs Synthesize Complex Climate Statements? (Lu, ClimateNLP 2025)
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PDF:
https://preview.aclanthology.org/landing_page/2025.climatenlp-1.21.pdf