Risks from Nuclear Weapons

Rethink Priorities are investigating risks from nuclear weapons in order to determine:

• The extent to which nuclear risk reduction should be prioritised by effective altruists (and particularly longtermists)
• The most effective ways to reduce nuclear risk

This work is centred on investigating the likelihood of various nuclear conflict scenarios, how harmful those scenarios would be (particularly for the long-term future), what interventions are available for reducing those likelihoods and/or harms, and how cost-effective those interventions are. This research can mostly be divided into three categories:

1. Investigation of key uncertainties that are relevant across a range of nuclear war scenarios, such as:
   • What are the various ways a nuclear conflict could start and play out?
   • If nuclear conflict occurs, how many warheads are likely to be used, and against what kinds of targets?
   • If nuclear conflict occurs, how large would the effects on the climate and crop yields be?
   • Given various possible crop yield declines, how many people would die?
   • How might various future technological developments affect nuclear risk?
2. Modelling the likelihood and harms of nuclear conflicts between specific pairs or groups of countries, especially:
   • The US and Russia
   • China and its potential adversaries (the US, India, or Russia)
   • Perhaps India and Pakistan
3. Identifying, collating, and evaluating intervention options for reducing nuclear risk

(Note that there may be differences between where posts fit in that breakdown, the order in which posts were published, and the order in which they’re shown in this sequence.)

Rethink Priorities will also be partnering with Metaculus to run a nuclear risk forecasting tournament. Posts related to that tournament will also be included in this sequence.

Rethink Priorities’ work on these topics was initially led by Luisa Rodriguez, and is now led by Michael Aird.

Image photoshopped by Bob Jacobs.