Byzantium was in decline for seven centuries until the Ottomans pulled the plug. Rome was in decline for several centuries prior to its sacking.
Climate change and the accompanying plagues, droughts, famines, and calamities that accompany it might accelerate and exacerbate the state's capacity and willingness to respond to these crises, but all it might mean is that this is a new normal added to the reproleterization of American life.
I don't really have a point but it is just a thought that I (perhaps others) are going to have to accept that future, and that is a kind of new world I am unsure as to how to adapt to.
If we look at current fault lines and on how neoliberalism operates i'd imagine it would look something like 4-5 new countries with some areas as left behind wastelands
If you look at current cities like Detroit or Flint which have been left to rot or areas of Alabama where hookworm is thriving (a disease of extreme poverty) you could easily extrapolate that in an economic collapse in huge areas that eventually get ruled by extreme Christian militias
Hell the current Secretary of State is an evangelical Christian and the US hasnt hit real hard times yet. When hard times come to US most of the Christian rural areas will go fascist without battering an eyelid and you'll see a Christian fascism quite similar to Spain under Franco or Pre ww2 Poland under Pilzudski
During the height of the pandemic States were smuggling PPE equipment across state lines to hide them from the Federal gov
The cracks are already there and with Russia and China spending the last 6 years whittling down their dollar holdings and a looming economic catastrophe the US is running on borrowed time