Seriously. We don't need to lose the ability to generate electricity to have an apocalypse. Just think about what would happen if plastic stopped being cost-effective for food storage and use in fabrics. Half of the items in the grocery story would shoot up in price and lose shelf life. People already go hungry enough. Clothes would be vastly more expensive, fit much worse and not last as long. Without a replacement for all the plastic we use, we'll have a civilization-wide catastrophe.
What would happen? We'd grow and eat local foods (the market for long range fuel-hungry transported, plastic packed goods disappears for farms near you, so they shift to something that does have a market - human consumable local demand), shift to a greater % of vegetables to more efficiently use biomass for human calories, and be a lot healthier, is probably what would happen. Price of food would probably remain about like it is, since
1) shipping costs are removed and
2) yield per acre shoots up (yield is always
much higher for local organic farms and gardens per acre!), and
3) Less meat = more efficient land usage, VERSUS
4) More expensive labor
#1-3 are likely to balance out #4, or exceed it.
Storage is a non-issue for local produce most of the year, as you eat as you grow. Over winter, you can easily survive on canned goods (can yourself, or local specialist if preferred), and root vegetables without any plastics.
Yes on the clothes being more expensive. No on the fit or quality - handmade clothes are mechanically always stronger due to stitching physics (even if only on a minority of key seams), and can fit much better due to the maker having access to your body and measurements, unlike Chinese factory workers.
The vast majority of our petroleum needs are for luxury convenience, NOT "need" of any sort.You WANT to eat Tostidos carne asada taco rolls or whatever, with plastic packaging, refrigeration, and ingedients from 17 states.
You do NOT NEED to eat Tostidos carne asada taco rolls. You could eat garden-grown turnip and kale soup instead from 50 feet outside of your kitchen.