Proceedings of the 2nd Workshop on Natural Language Processing Meets Climate Change (ClimateNLP 2025)

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 (Editors)


Anthology ID:
2025.climatenlp-1
Month:
July
Year:
2025
Address:
Bangkok, Thailand
Venues:
ClimateNLP | WS
SIG:
Publisher:
Association for Computational Linguistics
URL:
https://preview.aclanthology.org/acl25-workshop-ingestion/2025.climatenlp-1/
DOI:
ISBN:
979-8-89176-259-6
Bib Export formats:
BibTeX
PDF:
https://preview.aclanthology.org/acl25-workshop-ingestion/2025.climatenlp-1.pdf

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Proceedings of the 2nd Workshop on Natural Language Processing Meets Climate Change (ClimateNLP 2025)
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

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Enhancing Retrieval for ESGLLM via ESG-CID: A Disclosure Content Index Finetuning Dataset for Mapping GRI and ESRS
Shafiuddin Rehan Ahmed | Ankit Shah | Quan Hung Tran | Vivek Khetan | Sukryool Kang | Ankit Mehta | Yujia Bao | Wei Wei

Climate change has intensified the need for transparency and accountability in organizational practices, making Environmental, Social, and Governance (ESG) reporting increasingly crucial. Frameworks like the Global Reporting Initiative (GRI) and the new European Sustainability Reporting Standards (ESRS) aim to standardize ESG reporting, yet generating comprehensive reports remains challenging due to the considerable length of ESG documents and variability in company reporting styles. To facilitate ESG report automation, Retrieval-Augmented Generation (RAG) systems can be employed, but their development is hindered by a lack of labeled data suitable for training retrieval models. In this paper, we leverage an underutilized source of weak supervision—the disclosure content index found in past ESG reports—to create a comprehensive dataset, ESG-CID, for both GRI and ESRS standards. By extracting mappings between specific disclosure requirements and corresponding report sections, and refining them using a Large Language Model as a judge, we generate a robust training and evaluation set. We benchmark popular embedding models on this dataset and show that fine-tuning BERT-based models can outperform commercial embeddings and leading public models, even under temporal data splits for cross-report style transfer from GRI to ESRS.

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Judging It, Washing It: Scoring and Greenwashing Corporate Climate Disclosures using Large Language Models
Marianne Chuang | Gabriel Chuang | Cheryl Chuang | John Chuang

We study the use of large language models (LLMs) to both evaluate and greenwash corporate climate disclosures. First, we investigate the use of the LLM-as-a-Judge (LLMJ) methodology for scoring company-submitted reports on emissions reduction targets and progress. Second, we probe the behavior of an LLM when it is prompted to greenwash a response subject to accuracy and length constraints. Finally, we test the robustness of the LLMJ methodology against responses that may be greenwashed using an LLM. We find that two LLMJ scoring systems, numerical rating and pairwise comparison, are effective in distinguishing high-performing companies from others, with the pairwise comparison system showing greater robustness against LLM-greenwashed responses.

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Bridging AI and Carbon Capture: A Dataset for LLMs in Ionic Liquids and CBE Research
Sougata Saha | Gaurab Sarkar

Large Language Models (LLMs) have demonstrated exceptional performance in general knowledge and reasoning tasks across various domains. However, their effectiveness in specialized scientific fields like Chemical and Biological Engineering (CBE) remains underexplored. Addressing this gap requires robust evaluation benchmarks that assess both knowledge and reasoning capabilities in these niche areas, which are currently lacking. To bridge this divide, we present a comprehensive empirical analysis of LLM reasoning capabilities in CBE, with a focus on Ionic Liquids (ILs) for carbon sequestration—an emerging solution for mitigating global warming. We develop and release an expert-curated dataset of 5,920 examples designed to benchmark LLMs’ reasoning in this domain. The dataset incorporates varying levels of difficulty, balancing linguistic complexity and domain-specific knowledge. Using this dataset, we evaluate three open-source LLMs with fewer than 10 billion parameters. Our findings reveal that while smaller general-purpose LLMs exhibit basic knowledge of ILs, they lack the specialized reasoning skills necessary for advanced applications. Building on these results, we discuss strategies to enhance the utility of LLMs for carbon capture research, particularly using ILs. Given the significant carbon footprint of LLMs, aligning their development with IL research presents a unique opportunity to foster mutual progress in both fields and advance global efforts toward achieving carbon neutrality by 2050. Dataset link: https://github.com/sougata-ub/llms_for_ionic_liquids

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Applying the Character-Role Narrative Framework with LLMs to Investigate Environmental Narratives in Scientific Editorials and Tweets
Francesca Grasso | Stefano Locci | Manfred Stede

Communication aiming to persuade an audience uses strategies to frame certain entities in ‘character roles’ such as hero, villain, victim, or beneficiary, and to build narratives around these ascriptions. The Character-Role Framework is an approach to model these narrative strategies, which has been used extensively in the Social Sciences and is just beginning to get attention in Natural Language Processing (NLP). This work extends the framework to scientific editorials and social media texts within the domains of ecology and climate change. We identify characters’ roles across expanded categories (human, natural, instrumental) at the entity level, and present two annotated datasets: 1,559 tweets from the Ecoverse dataset and 2,150 editorial paragraphs from Nature & Science. Using manually annotated test sets, we evaluate four state-of-the-art Large Language Models (LLMs) (GPT-4o, GPT-4, GPT-4-turbo, LLaMA-3.1-8B) for character-role detection and categorization, with GPT-4 achieving the highest agreement with human annotators. We then apply the best-performing model to automatically annotate the full datasets, introducing a novel entity-level resource for character-role analysis in the environmental domain.

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Integrating Expert Labels into LLM-based Emission Goal Detection: Example Selection vs Automatic Prompt Design
Marco Wrzalik | Adrian Ulges | Anne Uersfeld | Florian Faust | Viola Campos

We address the detection of emission reduction goals in corporate reports, an important task for monitoring companies’ progress in addressing climate change. Specifically, we focus on the issue of integrating expert feedback in the form of labeled example passages into LLM-based pipelines, and compare the two strategies of (1) a dynamic selection of few-shot examples and (2) the automatic optimization of the prompt by the LLM itself. Our findings on a public dataset of 769 climate-related passages from real-world business reports indicate that automatic prompt optimization is the superior approach, while combining both methods provides only limited benefit. Qualitative results indicate that optimized prompts do indeed capture many intricacies of the targeted emission goal extraction task.

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ClimateIE: A Dataset for Climate Science Information Extraction
Huitong Pan | Mustapha Adamu | Qi Zhang | Eduard Dragut | Longin Jan Latecki

The rapid growth of climate science literature necessitates advanced information extraction (IE) systems to structure knowledge for researchers and policymakers. We introduce ClimateIE, a novel framework combining taxonomy-guided large language model (LLM) annotation with expert validation to address three core tasks: climate-specific named entity recognition, relationship extraction, and entity linking. Our contributions include: (1) the ClimateIE-Corpus—500 climate publications annotated via a hybrid human-AI pipeline with mappings to the extended GCMD+ taxonomy; (2) systematic evaluation showing Llama-3.3-70B achieves state-of-the-art performance (strict F1: 0.378 NER, 0.367 EL), outperforming larger commercial models (GPT-4o) and domain-adapted baselines (ClimateGPT) by 11-58%; and (3) analysis revealing critical challenges in technical relationship extraction (MountedOn: 0.000 F1) and emerging concept linking (26.4% unlinkable entities). Upon acceptance, we will release the corpus, toolkit, and guidelines to advance climate informatics, establishing benchmarks for NLP in Earth system science and underscoring the need for dynamic taxonomy governance and implicit relationship modeling.

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Biodiversity ambition analysis with Large Language Models
Stefan Troost | Roos Immerzeel | Christoph Krueger

The Kunming-Montreal Global Biodiversity Framework (GBF) has 23 action-oriented global targets for urgent action over the decade to 2030. Parties committing themselves to the targets set by the GBF are required to share their national targets and biodiversity plans. In a case study on the GBF target to reduce pollution risks, we analyze the commitments of 110 different Parties, in 6 different languages. Obtaining satisfactory results for this target, we argue that using Generative AI can be very helpful under certain conditions, and it is a relatively small step to scale up such an analysis for other GBF targets.

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AI and Climate Change Discourse: What Opinions Do Large Language Models Present?
Marcelo Sartori Locatelli | Pedro Dutenhefner | Arthur Buzelin | Pedro Loures Alzamora | Yan Aquino | Pedro Augusto Torres Bento | Samira Malaquias | Victoria Estanislau | Caio Santana | Lucas Dayrell | Marisa Affonso Vasconcelos | Wagner Meira Jr. | Virgilio Almeida

Large Language Models (LLMs) are increasingly used in applications that shape public discourse, yet little is known aboutwhether they reflect distinct opinions on global issues like climate change. This study compares climate change-relatedresponses from multiple LLMs with human opinions collected through the People’s Climate Vote 2024 survey (UNDP – UnitedNations Development Programme and Oxford, 2024). We compare country and LLM”s answer probability distributions and apply Exploratory Factor Analysis (EFA) to identify latent opinion dimensions. Our findings reveal that while LLM responsesdo not exhibit significant biases toward specific demographic groups, they encompass a wide range of opinions, sometimesdiverging markedly from the majority human perspective.

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Evaluating Retrieval Augmented Generation to Communicate UK Climate Change Information
Arjun Biswas | Hatim Chahout | Tristan Pigram | Hang Dong | Hywel T.p. Williams | Fai Fung | Hailun Xie

There is a huge demand for information about climate change across all sectors as societies seek to mitigate and adapt to its impacts. However, the volume and complexity of climate information, which takes many formats including numerical, text, and tabular data, can make good information hard to access. Here we use Large Language Models (LLMs) and Retrieval Augmented Generation (RAG) to create an AI agent that provides accurate and complete information from the United Kingdom Climate Projections 2018 (UKCP18) data archive. To overcome the problematic hallucinations associated with LLMs, four phases of experiments were performed to optimize different components of our RAG framework, combining various recent retrieval strategies. Performance was evaluated using three statistical metrics (faithfulness, relevance, coverage) as well as human evaluation by subject matter experts. Results show that the best model significantly outperforms a generic LLM (GPT-3.5) and has high-quality outputs with positive ratings by human experts. The UKCP Chatbot developed here will enable access at scale to the UKCP18 climate archives, offering an important case study of using RAG-based LLM systems to communicate climate information.

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An Automated LLM-based Pipeline for Asset-Level Database Creation to Assess Deforestation Impact
Avanija Menon | Ovidiu Serban

The European Union Deforestation Regulation (EUDR) requires companies to prove their products do not contribute to deforestation, creating a critical demand for precise, asset-level environmental impact data. Current databases lack the necessary detail, relying heavily on broad financial metrics and manual data collection, which limits regulatory compliance and accurate environmental modeling. This study presents an automated, end-to-end data extraction pipeline that uses LLMs to create, clean, and validate structured databases, specifically targeting sectors with a high risk of deforestation. The pipeline introduces Instructional, Role-Based, Zero-Shot Chain-of-Thought (IRZ-CoT) prompting to enhance data extraction accuracy and a Retrieval-Augmented Validation (RAV) process that integrates real-time web searches for improved data reliability. Applied to SEC EDGAR filings in the Mining, Oil & Gas, and Utilities sectors, the pipeline demonstrates significant improvements over traditional zero-shot prompting approaches, particularly in extraction accuracy and validation coverage. This work advances NLP-driven automation for regulatory compliance, CSR (Corporate Social Responsibility), and ESG, with broad sectoral applicability.

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Detecting Hyperpartisanship and Rhetorical Bias in Climate Journalism: A Sentence-Level Italian Dataset
Michele Joshua Maggini | Davide Bassi | Pablo Gamallo

We present the first Italian dataset for joint hyperpartisan and rhetorical bias detection in climate change discourse. The dataset comprises 48 articles (1,010 sentences) from far-right media outlets, annotated at sentence level for both binary hyperpartisan classification and a fine-grained taxonomy of 17 rhetorical biases. Our annotation scheme achieves a Cohen’s kappa agreement of 0.63 on the gold test set (173 sentences), demonstrating the complexity and reliability of the task. We conduct extensive analysis revealing significant correlations between hyperpartisan content and specific rhetorical techniques, particularly in climate change, Euroscepticism, and green policy coverage. To the best of our knowledge, we are the first to tackle hyperpartisan detection related to logical fallacies. Indeed, we studied their correlation. Moreover, up to our knowledge no previous work focused on hyperpartisan at sentence level. Our experiments with state-of-the-art language models (GPT-4o-mini) and Italian BERTbase models establish strong baselines for both tasks, while highlighting the challenges in detecting subtle manipulation strategies applied with rhetorical biases. To ensure reproducibility while addressing copyright concerns, we release article URLs, article id and paragraph’s number alongside comprehensive annotation guidelines. This resource advances research in cross-lingual propaganda detection and provides insights into the rhetorical strategies employed in Italian climate change discourse. We provide the code and the dataset to reproduce our results: https://anonymous.4open.science/r/Climate_HP-RB-D5EF/README.md

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Scaling Species Diversity Analysis in Carbon Credit Projects with Large-Context LLMs
Jessica Walkenhorst | Colin McCormick

Reforestation and revegetation projects can help mitigate climate change because plant growth removes CO2 from the air. However, the use of non-native species and monocultures in these projects may negatively affect biodiversity. Here, we describe a data pipeline to extract information about species that are planted or managed in over 1,000 afforestation/reforestation/revegetation and improved forest management projects, based on detailed project documentation. The pipeline leverages a large-context LLM and results in a macro-averaged recall of 79% and a macro-averaged precision of 89% across all projects and species.

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ClimateEval: A Comprehensive Benchmark for NLP Tasks Related to Climate Change
Murathan Kurfali | Shorouq Zahra | Joakim Nivre | Gabriele Messori

ClimateEval is a comprehensive benchmark designed to evaluate natural language processing models across a broad range of tasks related to climate change. ClimateEval aggregates existing datasets along with a newly developed news classification dataset, created specifically for this release. This results in a benchmark of 25 tasks based on 13 datasets, covering key aspects of climate discourse, including text classification, question answering, and information extraction. Our benchmark provides a standardized evaluation suite for systematically assessing the performance of large language models (LLMs) on these tasks. Additionally, we conduct an extensive evaluation of open-source LLMs (ranging from 2B to 70B parameters) in both zero-shot and few-shot settings, analyzing their strengths and limitations in the domain of climate change.

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Bidirectional Topic Matching: Quantifying Thematic Intersections Between Climate Change and Climate Mitigation News Corpora Through Topic Modelling
Raven Adam | Marie Kogler

Bidirectional Topic Matching (BTM) is a novel method for cross-corpus topic modeling that quantifies thematic overlap and divergence between corpora. BTM is a flexible framework that can incorporate various topic modeling approaches, including BERTopic, Top2Vec, and Latent Dirichlet Allocation (LDA). It employs a dual-model approach, training separate topic models for each corpus and applying them reciprocally to enable comprehensive cross-corpus comparisons. This methodology facilitates the identification of shared themes and unique topics, providing nuanced insights into thematic relationships. A case study on climate news articles illustrates BTM’s utility by analyzing two distinct corpora: news coverage on climate change and articles focused on climate mitigation. The results reveal significant thematic overlaps and divergences, shedding light on how these two aspects of climate discourse are framed in the media.

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CPIQA: Climate Paper Image Question Answering Dataset for Retrieval-Augmented Generation with Context-based Query Expansion
Rudra Mutalik | Abiram Panchalingam | Loitongbam Gyanendro Singh | Timothy J. Osborn | Ed Hawkins | Stuart E. Middleton

Misinformation about climate science is a serious challenge for our society. This paper introduces CPIQA (Climate Paper Image Question-Answering), a new question-answer dataset featuring 4,551 full-text open-source academic papers in the area of climate science with 54,612 GPT-4o generated question-answer pairs. CPIQA contains four question types (numeric, figure-based, non-figure-based, reasoning), each generated using three user roles (expert, non-expert, climate sceptic). CPIQA is multimodal, incorporating information from figures and graphs with GPT-4o descriptive annotations. We describe Context-RAG, a novel method for RAG prompt decomposition and augmentation involving extracting distinct contexts for the question. Evaluation results for Context-RAG on the benchmark SPIQA dataset outperforms the previous best state of the art model in two out of three test cases. For our CPIQA dataset, Context-RAG outperforms our standard RAG baseline on all five base LLMs we tested, showing our novel contextual decomposition method can generalize to any LLM architecture. Expert evaluation of our best performing model (GPT-4o with Context-RAG) by climate science experts highlights strengths in precision and provenance tracking, particularly for figure-based and reasoning questions.

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Robust Table Information Extraction from Sustainability Reports: A Time-Aware Hybrid Two-Step Approach
Hendrik Weichel | Martin Simon | Jörg Schäfer

The extraction of emissions-related information from annual reports has become increasingly important due to the Corporate Sustainability Reporting Directive (CSRD), which mandates greater transparency in sustainability reporting. As a result, information extraction (IE) methods must be robust, ensuring accurate retrieval while minimizing false values. While large language models (LLMs) offer potential for this task, their black-box nature and lack of specialization in table structures limit their robustness – an essential requirement in risk-averse domains. In this work, we present a two-step hybrid approach which optimizes both accuracy and robustness. More precisely, we combine a rule-based step for table IE with a regularized LLM-based step, both leveraging temporal prior knowledge. Our tests demonstrate the advantages of combining structured rules with LLMs. Furthermore, the modular design of our method allows for flexible adaptation to various IE tasks, making it a practical solution for industry applications while also serving as a scalable assistive tool for information extraction.

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Listen to the Context: Towards Faithful Large Language Models for Retrieval Augmented Generation on Climate Questions
David Thulke | Jakob Kemmler | Christian Dugast | Hermann Ney

Large language models that use retrieval augmented generation have the potential to unlock valuable knowledge for researchers, policymakers, and the public by making long and technical climate-related documents more accessible. While this approach can help alleviate factual hallucinations by relying on retrieved passages as additional context, its effectiveness depends on whether the model’s output remains faithful to these passages. To address this, we explore the automatic assessment of faithfulness of different models in this setting. We then focus on ClimateGPT, a large language model specialised in climate science, to examine which factors in its instruction fine-tuning impact the model’s faithfulness. By excluding unfaithful subsets of the model’s training data, we develop ClimateGPT Faithful+, which achieves an improvement in faithfulness from 30% to 57% in supported atomic claims according to our automatic metric.

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Interactive platform for the exploration of large-scale ‘living’ systematic maps
Tim Repke

Research syntheses, such as systematic maps or evidence and gap maps, provide valuable overviews of the coverage of research in a particular field.They serve as pointers for funders and researchers to identify important gaps in the literature where more research is needed but also to find relevant work for more in-depth systematic reviews or meta-analyses.However, systematic maps become outdated quickly, sometimes even after they are released due to the time it takes to screen and code the available literature and long publication processes.Furthermore, the write-up of the synthesis (in form of a peer-reviewed article) can only serve as a high-level summary—for detailed questions one would need full access to the underlying data.To this end, we developed an interactive web-based platform to share annotated datasets.For some datasets, where automated categorisation passes the necessary scientific quality standards, we also update the data as new research becomes available and thus make them ‘living’.

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Transforming adaptation tracking: benchmarking Transformer-based NLP approaches to retrieve adaptation-relevant information from climate policy text
Jetske Bonenkamp | Robbert Biesbroek | Ioannis N. Athanasiadis

The voluminous, highly unstructured, and intersectoral nature of climate policy data resulted in increased calls for automated methods to retrieve information relevant to climate change adaptation. Collecting such information is crucial to establish a large-scale evidence base to monitor and evaluate current adaptation practices. Using a novel, hand-labelled dataset, we explored the potential of state-of-the-art Natural Language Processing methods and compared the performance of various Transformer-based solutions to classify text based on adaptation-relevance in both zero-shot and fine-tuned settings. We find that fine-tuned, encoder-only models, particularly those pre-trained on data from a related domain, are best suited to the task, outscoring zero-shot and rule-based approaches. Furthermore, our results show that text granularity played a crucial role in performance, with shorter text splits leading to decreased performance. Finally, we find that excluding records with below-moderate annotator confidence enhances model performance. These findings reveal key methodological considerations for automating and upscaling text classification in the climate change (adaptation) policy domain.

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LLM-Driven Estimation of Personal Carbon Footprint from Dialogues
Shuqin Li | Huifang Du | Haofen Wang

Personal Carbon Footprint (PCF) Estimation is crucial for raising individual environmental awareness by linking daily activities to their environmental impact. However, existing tools are limited by fragmented scenarios and labor-intensive manual data entry. We present PCCT, an LLM-powered system that combines conversational understanding with emission knowledge grounding for PCF Estimation. We address two key challenges: (1) resolving incomplete activity information across turns through knowledge-guided and context-aware tracking, and (2) accurately mapping emission factors using multi-step LLM inference and vector-based similarity search. The system dynamically combines knowledge-guided activity extraction, and context-aware memory management, generating accurate carbon footprint estimates. We validate the effectiveness with the CarbonDialog-1K benchmark, comprising 1,028 annotated user activity narratives. Experimental results demonstrate that our method outperforms baseline systems in accuracy, while subjective evaluations show superior appropriateness, usability, efficiency, and naturalness.

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Can Reasoning LLMs Synthesize Complex Climate Statements?
Yucheng Lu

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.