Underground housing, underground businesses, etc. Would that be better for the environment + possibly save on energy costs? Also possibly safer in certain scenarios like tornadoes etc.
Potential issues that immediately come to mind are ventilation, earthquakes, and flooding. But it’s not like underground dwellings/basements/etc. aren’t a thing, so maybe those issues have been addressed in ways I’m not familiar with.
Not really, no. This is the same kind of silver-bullet thinking as self-driving cars, it may feel cool but in reality the best way to improve things are boring and have been known for centuries if not millennia.
Some things absolutely benefit from being underground, like railways in dense urban areas, but for most things it’s just a ton of effort for not much benefit and introducing a bunch of problems (flooding is only going to become more common in the future).
What we should be doing is returning to everything being designed for the specific local environment, stop building everything identically all over the world.
Look at traditional construction and you’ll find tons of small features that together make a HUGE difference, a prime example is how hot places had walled backyard gardens with a fountain in the middle, which basically turns the garden into a swamp cooler.