About Why Vendors Disagree: A Practical Guide to Evaluating Physical Climate Risk Data Vendors

In June 2026, ILN realised a white paper titled “Why Vendors Disagree,” a practical guide for institutional investors navigating the crowded marketplace of physical climate risk data providers. Drawing on engagements with seven vendors between June 2025 and April 2026, the paper examines why leading vendors – even when assessing the same asset – frequently arrive at significantly different conclusions about physical risk exposure, and introduces a structured evaluation framework across eight methodological categories to help investors assess vendors systematically. A key finding is that not all disagreement signals poor methodology: where approaches are rigorous and well-justified, divergent outputs add valuable perspective on an uncertain future – but where they are not, investors risk blind spots or maladaptation. The paper was prepared under the ILN’s Climate Change Advisory Committee, authored by Nik C. Steinberg.