Reply #10: I've been in both the Atlanta and Toronto undergrounds.

[GliderGuider]

They are essentially commercial facilities, not living quarters. The technological and financial investment required to create and maintain them takes them well out of the realm of feasibility when it comes to housing huge numbers of climate refugees from above ground - especially poor ones.

Yes, the global movement of climate refugees is going to be massive, and massively deadly. A lot of people are going to die as a result over the next half century, whether from thirst, starvation, disease or gunshots. Adjusting our global population down by 25% in 50 years is unlikely to be a pretty sight.

Technology and policy changes will save some of the fortunate ones, but are unlikely to do much for the desperately poor refugees from Africa or south-east Asia. They are the ones that will be doing much of the dying, not the inhabitants of Atlanta Underground.