They should start a national home insurance and compete with the private companies.
This won't work. Take any US state that is not too much affected, and tell them that now they have to pay a premium to insure the people of Florida. They will never do it.
I'm serious when I say that global warming and the lack of resources will break both the USA and China, and probably the EU too. The regions of those countries will be unwilling to pay for the others. Sweden won't pay forever for Spain, same in the respective regions of the USA and China. Do you really see these agglomerate of people supporting each others? I don't. The lack of food will have devastating effect on geopolitics.
We are leaving a period of prosperity and it's gonna shake a lot.