The ecological problem with skyscrapers is that they're inherently energy-intensive. If you live in the 5th floor you can either walk the entire thing (which is

The ecological problem with skyscrapers is that they're inherently energy-intensive. If you live in the 5th floor you can either walk the entire thing (which is still reasonable-ish), or take a lift 5 floors down and another 5 back up. If you live on the 50th floor, you have to travel a total of 100 floors every day. You're taking the lift, and taking 10x the energy to do so. Also, IIRC skyscrapers need machine-powered air ventilation which also takes power. Of course, the real killer might be the embodied energy - a 1-story flat can have a lot less embodied energy than an equivalent-sized 100-story skyscraper, simply because you can build the flat out of low-embodied-energy mud brick, whereas the skyscraper is necessarily high-strength steel with reinforced concrete anchoring underground. * But I think we're getting tunnel-vision. This is a social problem, perhaps it has a social solution. The important question here is: why are some plots of land so much more valuable to live on, than others? Perhaps if instead of spending money on building more skyscrapers, we instead spent it on decentralising, more people would be able to live in bumfuck-nowhere and that would reduce demand for existing skyscrapers without a ton of energy-expensive construction. There are plenty of rapidly emptying small towns around, after all. IMO silicon valley is public enemy #1 here - surely the IT industry is more suited to remote working and doesn't need some of the (AFAICT) most expensive housing in the entire US. That really suggests to me that there's a ripe juicy social problem that would dribble out a ton of benefits when bitten into.