In October of 2018, I developed a question series on Metaculus related to extinction events spanning risks from nuclear war, bio-risk, risks from climate change and geo-engineering, Artificial Intelligence risk, and risks from nanotechnology failure modes. Since then, these questions have accrued over 3,000 predictions (ETA: as of today, there the number is around 5,000).
Catastrophes were defined as a reduction in the human population of at least 10% in any period of 5 years or less. (Near) extinction is defined as an event that reduces the human population by at least 10% within 5 years, and by at least 95% within 25 years.
Here's a summary of the results as they stand today (September 24, 2023), ordered by risk of near extinction:
Global catastrophic risk | Chance of catastrophe by 2100 | Chance of (near) extinction by 2100 |
Artificial Intelligence | 6.16% | 3.39% |
Other risks | 1.52% | 0.13% |
Biotechnology or bioengineered pathogens | 1.52% | 0.07% |
Nuclear war | 2.86% | 0.06% |
Nanotechnology | 0.02% | 0.01% |
Climate change or geo-engineering | 0.00% | 0.00% |
Natural pandemics | 0.62% | N/A |
These predictions are generated by aggregating forecasters' individual predictions based on their track records. Specifically, the predictions are weighted by a function of the forecasters' level of 'skill', where 'skill' is estimated with data on relative performance on a number (typically many hundreds) of resolved forecasts.
If we assume that these events are independent, the predictions suggest that there's at a ~17% chance of catastrophe, and a ~1.9% chance of (near) extinction by the end of the century. Admittedly, independence is likely to be an inappropriate assumption, since, for example, some catastrophes could exacerbate other global catastrophic risks.[1]
Interestingly, the predictions indicate that although nuclear risk and bioengineered pathogens are most likely to result in a major catastrophe, an AI failure mode is by far the biggest source of extinction-level risk—it is at least 5-times more likely to cause near extinction than all other risks combined.
Links to all the questions on which these predictions are based may be found here.
For reference, these were the estimates when I first posted this (19 Jun 2022):
Global catastrophic risk | Chance of catastrophe by 2100 | Chance of (near) extinction by 2100 |
Artificial Intelligence | 3.06% | 1.56% |
Other risks | 1.36% | 0.11% |
Biotechnology or bioengineered pathogens | 2.21% | 0.07% |
Nuclear war | 1.87% | 0.06% |
Nanotechnology | 0.17% | 0.06% |
Climate change or geo-engineering | 0.51% | 0.01% |
Natural pandemics | 0.51% | n/a |
Forum readers who are not frequently on Metaculus may be interested in knowing that there are a number of biases and internal validity issues for long-term predictions on Metaculus, potentially more so than for short term questions there. For example, arguably the most important long-term question on Metaculus:
has comments like:
I think nonzero predictors take these comments quite seriously, or for other reasons are fairly flippant about finding out accurate answers to these long-term questions. Thus, forum readers should be extra careful before deferring blindly to Metaculus about such questions, and thus rely more on other sources over Metaculus.
The strongest counterargument to my reasoning above might be something like "Metaculus is unusually public and quantitative as a platform. To the extent that Metaculus has visible errors, we may expect that other epistemic sources have other, potentially larger, invisible errors."(Analogy: the concept of "not even wrong" in science). I take this reasoning quite seriously but do not consider it overwhelming.
I think somewhat higher chance of users being alive than that, because of the big correlated stuff that EAs care about.