An Existential Risk is a Risk Event whose severity is so extreme that it threatens the very existence of humanity or at least its ability to organize the complex civilisation structures currently observed. While the likelihood of such risks might be exceedingly small compared to risks commonly identified and managed, the possibility of dramatic impact warrants principled investigation and (where possible) mitigating measures.
- Existencial risks are generally the extreme Tail Risk of known phenomena and risks, where the extrapolation to much higher severities cannot be realistically be excluded.
- Existential risks do not include secular phenomena that may significantly alter conditions for human life and culture but do not substantially prevent it in some (potentially regressive form). This set includes, for example, resource depletion, biodiversity loss, climate change (for some scenarios)
- Existential risks tend to be irreversible, at least over timescales that are relevant to human life
- Some classifications of existential risks may include more hypothetical extrapolations, e.g. the development of malevolent artificial intelligence or the developmet of other technologies with catastrophic potential. In the interest of brevity this subcategory is not included here
The potential risk types belonging the existencial risk category can be classified into anthropogenic (where the human factor plays the more important role) and non-anthropogenic, where natural causes are most important
- Extreme climate change (involving Tipping Points) that make the majority of land mass uninhabitable due to extreme athmospheric conditions. This is an extrapolation of the known impact of antrhopogenic factors at smaller scales.
- Weapons of mass destruction involving large scale impacts (as extrapolation of known smaller scale wars)
- Chemical Warfare
- Biological Warfare or
- Nuclear Warfare
- Biological (Viral Pandemics or other Diseases) as extrapolations of historical pandemics
- Geological with planetary origin (Extreme Volcanism or Earthquakes) as extrapolation of ongoing volcaning and earthquake activity
- Geological with solar origin (Asteroid Impact, Sun activity) as extrapolation of ongoing impact of solar system bodies and interaction with the Solar atmosphere
- Quantification of existencial risks in the anthropogenic sub-category is exceedingly difficult as it conditioned on global behaviors over long periods of time.
- Quantification of existencial risks in the non-antrhopogenic sub-category is general easier with reference to historical observed distributions. The extreme tail might still be difficult to assess
Existential risk is increasingly being reflected in policy discussion and measures (Nuclear Non-proliferation, Bans on Chemical / Biological Weapons)
Other mitigation activities are primarily addressing the lower severity versions and tend to be local rather than global in nature (WHO)