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.
Arrighi put forward in The Long Twentieth Century that during the capitalist epoch, there has been a cycle that has repeated several times, of one hegemonic empire replacing another. Each time, the empire has risen out of the ashes of a previous one, using finance from the previous empire to establish a huge manufacturing base, surpassing the previous hegemon as it declines. Then, after a period of time, the new power runs out of new markets to exploit and switches from a trade/manufacturing economy, to one increasingly based on finance - using the money (gained from empire over decades and centuries) to make more money, rather than making money from products.
I believe he analyses the venetians, the Spanish, the dutch, and the British empire, as well as the American one, and they all follow this pattern.
Interestingly enough, he also asserts that each time the cycle of rise —> dominance —> decline has occurred, it has happened faster and faster, that is to say the empires have risen and fallen quicker each time.
The American economy has been extremely based on finance since the 70s, and they’ve definitely been in decline for some time. If the pattern Arrighi points out holds true, the American empire will fall hard and fast.
And one more ominous thing from Arrighi - he also shows that every time a hegemonic empire is falling, there have been huge, worldwide conflagrations of war and suffering to establish the successor! So that’s something to look forward to. Think WWI/WWII as the Brits were fading, Napoleonic Wars as the Dutch declined, and so on.