I am worried about the disposal problem presented by all this glass. It tends to blow out of the highrises from differential air pressure over time (rising suddenly inside over outside a building under certain storm conditions), & then smash when it lands. This will make the area formerly occupied by cities inconvenient & even dangerous to hike through, for glass doesn’t degrade biologically & may require millions of years to be geologically recycled. And if you’ve ever had to clean up broken glass, you’ll know what a pain it is.
Worse, so much of our prime farmland is directly underneath these cities. Though come to think of it, our Upper Canadian pioneers didn’t have it much better clearing rocks & pulling tree roots. One must, I suppose, take it one acre at a time; then choose the succession of crops wisely to restore the soil. And avoid moaning that when the glass is ground up — again, patience is required for the manual operation — all you get is sand.
Whereas, bricks make good rubble for re-facing with stone, & cars can provide useful metal when they are melted down. Some could perhaps be beaten into ploughshares. There is also plenty of wood in furnishings & interiors to keep our descendants warm through the winters; paper & upholstery to light it; & the odd delightful trinket with which their children may play.
Better to look on this brighter side.