How bad could a war get?

Abstract

Acknowledgements: Thanks to Joe Benton for research advice and Ben Harack and Max Daniel for feedback on earlier drafts. Author contributions: Stephen and Rani both did research for this post; Stephen wrote it and Rani gave comments and edits. Previously in this series: “Modelling great power conflict as an existential risk factor” and “How likely is World War III?” In “How Likely is World War III?”, Stephen suggested the chance of an extinction-level war occurring sometime this century is just under 1%. This was a simple, rough estimate, made in the following steps: Assume that wars, i.e. conflicts that cause at least 1000 battle deaths, continue to break out at their historical average rate of one about every two years. Assume that the distribution of battle deaths in wars follows a power law. Use parameters for the power law distribution estimated by Bear Braumoeller in Only the Dead to calculate the chance that any given war escalates to 8 billion battle deathsWork out the likelihood of such a war given the expected number of wars between now and 2100.