Congratulations, we can build your solution in 25 years. Maybe. If there's still enough water to run any of it. And food. But there won't be.

We really do not need much concrete or steel. What we need is bioplastics, biocomposites, wood, fused sand and a lot of farming practice changes. Some breakthrough in water desalination or cleanup. A lot of people will have to move.

There's no way around it now.