Some of the factors:
1) Shortages for items in general have been ongoing since the economic shutdown over the pandemic. China continues to do shutdowns.
2) Incredibly high fuel costs have lead to much higher costs for fertilizer and diesel. Some farmers simply cannot afford their fuel bills. Some have skipped fertilizing which will result in a poorer harvest. 1 ton of fertilizer cost about $400 last year. It's over a thousand a ton this year.
3) China had a poorer grain harvest last year due to floods followed by drought. They have been sucking up extra grains.
4) Inflation, inflation, inflation.
5) The war in Ukraine. Some farmers did not plant. Some farmers will not be able to harvest. Up to 50 percent of Ukraine's grain harvest may be lost, and they feed a lot of people. Other nations may take note of this impeding disaster and launch military action against Russia.
6) Rumors of a sharp diesel shortage later this summer could lead to infrequent deliveries of needed items across the U.S. This could greatly affect the grain harvest as well.
7) What's the deal with the food processing plant fires and such?
Potential results:
1) The world wide grain shortage could result in food shortages so severe that people simply cannot get enough carbs. Riots in 3rd world countries, even revolutions may result from this. Here, the shortage will likely result in people resorting to other carbs like potatoes and fruits, which may even lead to shortages for even these items later this summer and fall.
2) An expanding war in Europe. World war III. Some global powers may no longer sit by as their store shelves become more empty and their farmers can't afford fertilizer and fuel. Russia may get wiped out because of this.
3) The political upheaval. Many in power will pay the price for this. Violence, getting voted out, maybe even being drug out into the streets for their short sightedness.
Stock up on extra dry carbs. Stock up on canned goods. Plant a vegetable garden if you can, and keep your powder dry.