Practitioners across industries increasingly use large language models to extract information from unstructured documents such as financial filings, legal contracts, and sustainability reports, yet typically rely on generic online recommendations for prompt design that lack empirical grounding in their target setting. We address this gap with a practical methodology for systematically varying individual prompt components (prompt structure, contextual information, and model selection) and measuring their effect on extraction quality. We use greenhouse gas emissions extraction from corporate sustainability reports as a case study of fixed numeric extraction from high-stakes PDF documents that vary widely in structure and presentation and are dispersed across company websites. Instantiated in a retrieval-augmented generation pipeline, our evaluation shows that best practices from industry-facing prompting guides do not always hold: a structured prompt incorporating roles, definitions, extraction rules, and JSON formatting unexpectedly underperforms a simpler question-style prompt, while the benefit of adding tabular context proves both prompt- and model-specific. We condense our evaluation procedure and findings into a practitioner’s decision guide for systematically testing design choices on task-specific data rather than adopting generic recommendations by default.

Natural language processing (NLP) now shapes many aspects of our world, yet its potential for positive social impact is underexplored. This paper surveys work in “NLP for Social Good" (NLP4SG) across nine domains relevant to global development and risk agendas, summarizing principal tasks and challenges. We analyze ACL Anthology trends, finding that inclusion and AI harms attract the most research, while domains such as poverty, peacebuilding, and environmental protection remain underexplored. Guided by our review, we outline opportunities for responsible and equitable NLP and conclude with a call for cross-disciplinary partnerships and human-centered approaches to ensure that future NLP technologies advance the public good.

Automated extraction of corporate greenhouse gas (GHG) emissions from sustainability reports is critical for climate crisis governance, yet the choice of prompt design, context provision, and model in LLM-based pipelines is largely guided by informal best-practice recommendations rather than systematic evaluation. With **Climatextract**, we assess these choices in a RAG pipeline, comparing closed-source against open-weight models, a structured "best-practice" prompt against a simple question-style prompt, and text-only against text-plus-table contexts. We find that performance is non-monotonic across model generations, a structured prompt with roles, definitions, extraction rules, and JSON formatting is significantly outperformed by a question-style prompt, and tabular context helps only in a specific model-prompt combination. A cost-benefit analysis shows that performance gains are often disproportionate to cost increases.

Sustainability reports denote greenhouse gas emissions with heterogeneous unit strings, such as abbreviations, inconsistent formatting, and scale markers. In emission extraction pipelines, these units must be normalized to a common target, e.g. t CO2e, to enable reliable comparison and aggregation of emissions across companies, reporting years, scopes, and regions. We propose a hybrid normalization approach: If a raw unit string is not found in a curated dictionary, a machine learning classifier maps noisy unit strings to normalized emission-unit categories that can then be converted to the target unit. The classifier is trained using character-level TF-IDF, lightweight string features, and LLM-assisted data augmentation. On random-splits of the augmented dataset, an ensemble model achieves approximately 95% accuracy. Additional evaluation on rare real-world unit strings indicates that supervised fallback classifiers can handle out-of-dictionary variants in climate-related information extraction.