Thank you for this post, I have been trying to make this point to people! (about catastrophic risk in general not necessarily AI)

I wrote something similar recently which has a little interactive calculator for your risk based on age/gender if people are interested

Stockpiling food

Recovery from catastrophe

Many existential risk scenarios for involve some disaster (supervolcano, nuclear war, crop blight) followed by a long period in which it is very difficult to grow food.

The idea of this project is to create an organisation which buys cheap and calorie dense food and stores it to be used in the event of such a disaster.

This is importantly different, and complementary, to the ideas promoted by ALLFED to scale up food production very quickly using technology (e.g. creating food from trees). Scaling up food production is likely to have some lead time, and it is not at all certain that it would actually work in a real disaster. Having enough food to last 6 months to a year would give some runway to develop this technology, and it may be the case that most catastrophes that would cause famine only last about a year anyway in which case this approach would be sufficient.

Here's an order of magnitude estimate of what it would cost to store one year's worth of food in the UK to show it's plausible:

 - cost of white rice per 2000 calories: ~£1 (e.g. this one)

 - shelf life: ~10 years

 - population of UK: 70 million

 - total cost/year: (£1 * 365 * 70M) / 10 == £2.5 billion

This doesn't account for storage costs and interest rates, but on the other hand there might be fewer people to feed if lots of people die in a nuclear war, also there might be some other food around, and you don't actually need 2000 calories/day to survive

This is the perfect project for the current "overfunded" state of EA as it would require a lot of funding and be useful across a broad range of possible scenarios