Related Questions on Metaculus:

• If there's a nuclear conflict involving >1000 detonations, will that cause >4 billion fatalities within 10 years?

• If there's a nuclear conflict involving >100 detonations, will that cause >1 billion fatalities within 10 years?

• If there's a nuclear conflict involving >100 detonations, will that cause >1 million fatalities within 1 month?

• If there's a nuclear conflict involving >1000 detonations, will humanity be extinct within 50 years?

• If there's a nuclear conflict involving >1000 detonations, will humanity's population be <400 million 50 years later?

Decisions about how much to prioritize nuclear risk reduction and how best to reduce nuclear risk should be guided in part by our best guesses about:

• how many deaths would occur given a large-scale nuclear exchange

• what proportion of those deaths would occur fairly soon after the detonations (e.g., from the initial blast and fires) rather than later on (e.g., from fallout or nuclear winter effects)

For example, this is relevant to the existential risk posed by nuclear weapons and the value of investing in research and development on "resilient food".

See here, and the sources linked to from there, for previous discussion of these sorts of questions and why they matter.