it could be food shortages, crop losses or shipment disruptions
or it could be just very high prices, fuel costs , . money devalued, etc
who knows
but i would bet that things will not get cheaper and more abundant
first? probably beans rice etc that are many meals cheap
any extra at home is better than 90% of the people have now
as for timing, the wef type people say "soon" about as often as it is heard here
both sides probably mean it, but preperation never hurt anyone
if nothing else convince them to just stock up ahead of higher prices if they don't like the "tinfoil" type theories