---
client: ea_forum
project_id: curated
narrator: pw
qa: mds
narrator_time: 4h
qa_time: 30m
---

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:

1. 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. 
2. Assume that the distribution of battle deaths in wars follows a power law. 
3. 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 deaths
4. Work out the likelihood of such a war given the expected number of wars between now and 2100.

Not everybody was convinced. I (Stephen) have to admit that some skepticism is justified. An extinction-level war would be 30-to-100 times larger than World War II, the most severe war humanity has experienced so far. Is it reasonable to just assume number go up? Would the same escalatory dynamics that shape smaller wars apply at this scale?

Original article:
https://forum.effectivealtruism.org/posts/PyZCqLrDTJrQofEf7/how-bad-could-a-war-get

Narrated for the Effective Altruism Forum by TYPE III AUDIO.

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