shortage of staple food will cause price spike with related economical/political/social effects. Staple food isn't just a whimsical choice of consumer. Beside some exceptions (where people moved and brought their tradition with them), a staple food is a result of hundreds or thousands of years of evolutionary optimization for that population in that region. Milk in Europe is exactly such a case, and is a very important one to the population there. (see my other post in this thread https://news.ycombinator.com/item?id=7034795). Specifically, in case of milk in Norway any issues with its availability, in addition to short term price-spike related effects, would in long term affect negatively health and well being of children whose body/skeleton would be forming at the time.