Good thing we've been working on beating photosynthesis efficiency of turning sunlight into carbohydrates (e.g., sugar) by using special electrolysis cells to synthesize plant-accessible carbon-nutrients (one kinda-successful (in beating natural leaves with PV based sunlight electricity and their electrochemistry)) attempt focused on generating a nutrient solution rich in acetate from CO2 feed (and electricity); that's one of the energy carrier molecules that existing plant biology can efficiently utilize.

https://doi.org/10.1016/j.joule.2024.09.011

And note that by exploiting winter time solar yield and the grow houses with such technology not using sunlight directly and thus allowing easy and efficient thermal insulation, production could run year-round just with the amount of grow houses "online" varying with the average solar yield. Also gives convenient off-times (if they rotate which building runs through the winter) for maintenance.

And eating less meat or at least feeding the meat animals efficiently produced (but not as "tasty/varied/textured") plant/algae(/possibly-microbiological with bacteria or yeast) feed instead of things like Alfalfa that are very resource intensive to farm, would also help a lot with these issues.

Probably we should get back to doing grain bunkers as strategic reserves, though, lasting long enough to realize the problem, slaughter 80% of livestock, and plant low-failure-risk human suitable food crops on farmland that previously had feed crops for those no longer living 80% and land that had things like corn dedicated for ethanol that's then added to gasoline. Ideally ofc. we'd not need to cull as much life stock and could instead just slightly reduce new breeding and switch those corn fields to human food.