How to determine the largest global and national risks: Review and discussion

• Published in: Reliability engineering & system safety Vol. 199; pp. 106905 - 10
• Main Author: Aven, Terje
• Format: Journal Article
• Language: English
• Published: Barking Elsevier Ltd 01.07.2020; Elsevier BV
• Subjects: Environmental risk; Flooding; Global economy; Natural disasters; Reliability engineering; Risk; Security; Uncertainty
• ISSN: 0951-8320; 1879-0836
• DOI: 10.1016/j.ress.2020.106905

•The work addresses the issue how to determine the largest global and national risks.•Relevant perspectives on how to understand and describe the risks are evaluated.•The evaluation is based on three main criteria: validity, uncertainty and usefulness.•It is shown that only an ‘uncertainty-based’ perspective meets these criteria.•The paper provides guidance on how to improve current approaches. Does security risk represent a higher global risk than natural disasters? Is flooding risk globally greater than infrastructure failure risk? Such questions are answered using global and national risk metrics and characterisations, for example as conducted by the World Economic Forum and many national safety and security agencies. The metrics and characterisations aim to inform decision makers, politicians and the public in general about serious hazards and threats that we face today and, in this way, contribute to more science-informed policies and decisions. How to best identify the highest risks is, however, challenging. Strong criticism has been raised against current approaches, for example the one adopted by WEF. The present paper performs a review and discussion of the subject area – how to best determine the largest global and national risks − based on a study of theoretical rationale and developments of the risk concept and how to measure or describe it, as well as of quality aspects like validity, uncertainty and usefulness. Three main risk perspectives are considered as a basis for the evaluation: expected consequences (EC), consequences and probability (C,P) and consequences and uncertainty (C,U). Recommendations are presented, based on what is considered as current risk science knowledge.