Group Reasoning Emission Estimation Networks
Yanming Guo, Xiao Qian, Kevin Credit, Jin Ma
TL;DR
GREEN addresses the challenge of SME GHG reporting by standardizing enterprise emission estimation through NAICS-aligned carbon intensities. It combines ExioNAICS, SBERT with contrastive fine-tuning, and a Hierarchical Group Reasoning approach to map descriptions to 1,114 NAICS categories via an information retrieval formulation, ultimately computing emissions as $E = R \cdot I$. The framework achieves state-of-the-art NAICS-6 accuracy (83.68% top-1, 91.47% top-10) and a real-world MAPE of $45.88\%$ on a 20-company sample, while providing an open benchmark linking thousands of enterprises to emission factors from ExioML. By delivering an end-to-end, scalable pipeline for enterprise-level carbon accounting, GREEN has the potential to broaden adoption among SMEs and improve transparency in ESG reporting.
Abstract
Accurate greenhouse gas (GHG) emission reporting is critical for governments, businesses, and investors. However, adoption remains limited particularly among small and medium enterprises due to high implementation costs, fragmented emission factor databases, and a lack of robust sector classification methods. To address these challenges, we introduce Group Reasoning Emission Estimation Networks (GREEN), an AI-driven carbon accounting framework that standardizes enterprise-level emission estimation, constructs a large-scale benchmark dataset, and leverages a novel reasoning approach with large language models (LLMs). Specifically, we compile textual descriptions for 20,850 companies with validated North American Industry Classification System (NAICS) labels and align these with an economic model of carbon intensity factors. By reframing sector classification as an information retrieval task, we fine-tune Sentence-BERT models using a contrastive learning loss. To overcome the limitations of single-stage models in handling thousands of hierarchical categories, we propose a Group Reasoning method that ensembles LLM classifiers based on the natural NAICS ontology, decomposing the task into multiple sub-classification steps. We theoretically prove that this approach reduces classification uncertainty and computational complexity. Experiments on 1,114 NAICS categories yield state-of-the-art performance (83.68% Top-1, 91.47% Top-10 accuracy), and case studies on 20 companies report a mean absolute percentage error (MAPE) of 45.88%. The project is available at: https://huggingface.co/datasets/Yvnminc/ExioNAICS.
