Understanding and communicating uncertainty in natural hazard and risk information: a literature review

Uncertainty is inherent in natural hazard and risk information. It arises from the complexity of natural systems, limitations in data and models, and uncertainty about future environmental and societal change. Yet decisions about land use, infrastructure, emergency management, insurance and resilience still need to be made. This means uncertainty must be understood, managed and communicated in ways that support transparent and defensible decision-making.

This literature review supports the Natural Hazards Commission Toka Tū Ake (NHC Toka Tū Ake) in developing a methodology for assigning and communicating confidence levels to natural hazard and risk information. While not exhaustive, it draws together national and international literature on uncertainty, confidence, and risk communication, with a focus on what uncertainty is, why it matters, how it can be managed, and how it can be communicated effectively.

The review finds that poorly understood or poorly communicated uncertainty can contribute to inaction, overly conservative responses, inappropriate risk-taking, and reduced trust in science and decision-making. By contrast, acknowledging and communicating uncertainty clearly can improve transparency, strengthen trust, and support more proportionate and adaptable decisions.