If talking about the Western world, I have my guessing where they take it from: They import it from the rest of the world (just some more than usually).
Already is the case with potatoes this year.
The harvest last year supposedly wasn't so good because of the months-long dryness and heat from about April until long into autumn (even Winter was pretty dry) - but, don't think the shelves have been any emptier than usually.
So that means: If they're not from here, they just come from somewhere else...
Of course, prices will rise along with that because of actual "lack" on the market, but the practical side of things will be a totally different reality. Them taking a lot of payment, but spending the same money as usual on letting lesser developed countries with a bad currency do the job for them...

I guess, if this goes on as it is, and the developed world only takes from the third and second world counties what they don't have, without changing anything about their basic concept, it will only mean "more people wanting to go to Europe on a nutshell in the Mediterranean".
If you just take the food from other areas, but there's lesser on the market in the reality, people will quit because of starving and try to go to those areas they can have a base to live... (And that is where the food goes via the export/import route.)