If global existential risks became a big part of 2018-2023, it would be because someone did something incredibly stupid or awful with infectious diseases.

Read the claim as: any global existential-risk episode that became a major feature of 2018-2023 would come from human error or misuse involving infectious disease. 'Existential risk' means a credible threat of human extinction or permanent collapse of civilisation. A pandemic does not count just for being serious. It counts only if credible experts treated it as threatening civilisation itself. True: either no global existential-risk episode became a major feature of the period, or any that did stemmed from a demonstrated human-caused infectious-disease event (an engineered pathogen, a lab accident, bioterrorism). Mostly true: the only qualifying episode involved infectious disease, with human causation strongly supported but not fully established. Mixed: the only candidate episode involved an infectious disease of disputed origin (natural spillover versus a human-caused event), and it is contested whether it counts as existential. Mostly false: a major existential-risk concern arose mainly from another source, such as nuclear escalation or AI, alongside a minor disease-related one. False: a major existential-risk episode in 2018-2023 arose entirely from a non-infectious-disease cause.

Set before the research began.

1. E1 PRESS RELEASE: Doomsday Clock set at 90 seconds to midnight Bulletin of the Atomic Scientists · 24 January 2023

   “The Doomsday Clock was set at 90 seconds to midnight, due largely but not exclusively to Russia’s invasion of Ukraine and the increased risk of nuclear escalation. The new Clock time was also influenced by continuing threats posed by the climate crisis and the breakdown of global norms”

2. E2 The Precipice Revisited — Toby Ord Toby Ord (personal site) · 12 July 2024

   “Covid was not an existential risk. But it did have implications for such risks.”

3. E3 The Precipice Revisited — Toby Ord Toby Ord (personal site) · 12 July 2024

   “Existential risk from AI had finally gone from a speculative academic concern to a major new topic in global governance.”

4. E4 New reports show backing for lab leak theory, but government agencies remain divided PolitiFact · 2 March 2023

   “Every intelligence agency that participated in the report agreed that either the lab leak or the natural exposure theories were plausible, and that no credible evidence supported a third theory — that it had been developed as a biological weapon or was genetically engineered.”

In January 2023 the Bulletin of the Atomic Scientists set the Doomsday Clock at 90 seconds to midnight. It said this was "due largely but not exclusively" to Russia's invasion of Ukraine and the increased risk of nuclear escalation, and also cited the climate crisis and the breakdown of global norms; none of these causes involve infectious disease (E1). Toby Ord also writes that existential risk from AI became a major topic in global governance (E3). He says plainly that Covid "was not an existential risk" (E2), so no disease-related existential episode qualifies. The major existential-risk concerns of the period came from causes other than infectious disease, so under the criteria the prediction resolves false.