jojo's post and Toddy's both reminded me of something that I have thought about several times previously. Which is, we are so dependent on the global transportation grid. Particularly for our food.
We have all seen video on the news broadcast showing empty shelves in grocery stores when some major disaster happens or is just predicted.
If it really broke down for any length of time we would all be up against it in just a few days at best.
Yet if you think about the transportation grid of say 1870, and it had broken down, It wouldn't have mattered much as far as food was concerned. In the U.S., as late as 1900, 95 percent of the population was rural, and 5 percent was urban.
That means that 95 percent of the people had cows, chickens, pigs and grains. I'm sure the figures for the U.K. are comparable. It also means that 95 percent could have weathered any breakdown without hardly noticing that it was happening. Probably, sugar and coffee were the only two things that would have been really noticed.
Today, even the 5 percent that farm, don't butcher their own animals, don't make butter, seldom "can" food, etc. Many of these skills are not "lost", but are "lost" as far as most people are concerned.
All of this just illustrates how dependent, and inter-dependent we have become.