The only people who care about this are those for it and those against it. Who together form a very small minority. I call them both precious obsessives. To them I say get outside, touch grass, look at a cloud.
We'd do a different economy and society then. Not democratic capitalism of course. Something with total centralized control.
Our present system is vastly inefficient. 99% of our energy is spent in competition and friction. If we got properly organized, supplying the population with everything it needs would be trivial. Doubly so with heavy automation.
I think that the population would just shrink. People would freak out for a month then it would become the new normal. And we'd handle it. And suddenly everything would be cheaper and lots of nice forests would grow.
You people are extremely defensive.