No, not made up extremism. It is a risk which becomes more likely. Just for kicks, what happens if the existing, current drought in the US (worst in 1200 years

No, not made up extremism. It is a risk which becomes more likely. Just for kicks, what happens if the existing, current drought in the US (worst in 1200 years) continues and/or worsens over the next two years, cutting agricultural production and raising the cost of food (disclaimer: long CORN). https://droughtmonitor.unl.edu/ https://droughtmonitor.unl.edu/ And if a megaflood wipes out California. https://www.science.org/doi/10.1126/sciadv.abq0995 https://www.science.org/doi/10.1126/sciadv.abq0995 And a series of hurricanes causes extreme damage to the Eastern seaboard also shutting down Gulf refineries thus cutting oil/gas to the US https://www.reuters.com/business/energy/short-history-us-oil-refining-losses-due-hurricanes-2022-06-30/ https://www.reuters.com/business/energy/short-history-us-oil... None of those on its own is a civ killer. The problem is when each of these goes from exceedingly rare to rather common. And it isn't just the US, it is global.