Intriguing idea.

Bad premise to start out though: "We cannot live on the Mars"

Yes we can.

"We cannot live on Mars because its surface gravity is half of what we evolved in for millions of years. "

There is no evidence to support that. Micro/zero gravity is unhealthy for humans. But there is no evidence that _low_ gravity is unhealthy. In fact, 1/3 gravity might actually be very beneficial for a lot of people, especially those who have joint problems.

The premise is set up as a straw man: "Keep Earth itself as intact as possible" - as if that is an alternative than going to Mars; but there is no reason that keeping Earth intact is in opposition go going to Mars.

The article also says repeatedly "we", as if everyone must act in unison. But no one is being forced to go to Mars. And while I agree that it should not be funded using public funds, much of SpaceX's funding comes from private sources.

The article then makes an untenable premise: "We need to have a structure that scales exponentially as our population grows exponentially"

Why should we allow the human population to grow exponentially? Oever-population is the root cause of global warming. It is the root cause of pollution. It is the root cause of the sky-high housing prices that people pay in congested cities. If we want to be sustainable, we need to get our population under control - moving to the clouds is not an alternative to "keeping Earth intact", and if we "keep Earth intact", then we don't need to move to the clouds.

I think the idea is intriguing though. I can see some people wanting to live in the clouds. There are already floating cities on the ocean.

The scale imagined seems problematic - to create metal structures on that scale would require autonomous manufacturing (conceivable), but where would resource on that sclae come from? The asteroids perhaps - they would have to be transported to Earth. Seems like the overall effort would be too expensive by many orders of magnitude.

Flaoting on water is another matter. People are doing that already. It is an interesting idea.