I think the worry is, among others, that the reduced outputs from the grain regions of the US, Canada, Argentina, Russia, China, India can’t easily be replaced.
Even if it can be replaced the geo-political turmoil would likely be severe.
Not only food will be a concern, but we really do not know the kind of weather a seriously cooling Earth can produce. There exists some geological evidence for cantaloupe sized hail impacting the ground at over 90 mph. And what would happen as the Great Lake froze more solid and started devastating the local regions with ice flows ? Global Cooling should be the primary concern for science and Global Warming should be welcomed as an optimum for life. The US and EU governments have it backwards as usual.
S—t, I guess that means we have to do without ethanol.
That’s why the Food Luddites are so dangerous.
GMO is going to go a long ways to ameliorate the effects of cooling, but the Luddites want to put the brakes to what may be our salvation.