Nice work Ollie, this is very thought-provoking. It got me thinking a lot more about plausible reference classes for human extinction.
As I’ve mentioned to you, I think individual species extinctions are a better reference class than mass extinction events. It’s a shame you couldn’t find a good source that summarizes how quickly species declines tend to happen. Individual species must end faster than extinction events, since species collapses all occur within extinction events. And I strongly suspect if we had data on them, we’d see that species tend to go extinct much faster than extinction events. There’s selection bias at work, but I can recall seeing graphs of, e.g., global whale, elephant, and rhinocerous populations that show precipitous declines following an exogenous catastrophe (usually the introduction of humans, or the invention of a new technology like whaling ships).
Your discussion of civilizational decline timelines, on the other hand, does seem directly relevant. It would be great to see a database that tracks the duration of civilizational declines categorized by cause (where possible), to see if we can find more specific reference classes based on different risks!
Nice work Ollie, this is very thought-provoking. It got me thinking a lot more about plausible reference classes for human extinction.
As I’ve mentioned to you, I think individual species extinctions are a better reference class than mass extinction events. It’s a shame you couldn’t find a good source that summarizes how quickly species declines tend to happen. Individual species must end faster than extinction events, since species collapses all occur within extinction events. And I strongly suspect if we had data on them, we’d see that species tend to go extinct much faster than extinction events. There’s selection bias at work, but I can recall seeing graphs of, e.g., global whale, elephant, and rhinocerous populations that show precipitous declines following an exogenous catastrophe (usually the introduction of humans, or the invention of a new technology like whaling ships).
Your discussion of civilizational decline timelines, on the other hand, does seem directly relevant. It would be great to see a database that tracks the duration of civilizational declines categorized by cause (where possible), to see if we can find more specific reference classes based on different risks!
Thanks, Stephen! Yeah, excited to see more data in this space, all over the place.