Originally Posted by Chip

Venus would likely not sustain a basic two layer zoned atmosphere wherein the upper altitude provided a blanket of breathable oxygen-nitrogen air. A floating city would have to have its own air supply. This would make a floating city (basically a far-flung variant of a gigantic dirigible, though not in the shape of a giant dirigible,) irrelevant. It would be more technologically feasible from an engineering standpoint to then build a gigantic orbiting spacecraft-town but then why have it orbit Venus? Developing technology for a floating city would also be highly problematic. Turbulence in the upper atmosphere of Venus would again make an orbiting spacecraft-community safer, but why bother?

The (strong) domed surface structure is a more interesting idea. But actually, I think a hypothetically transformed Venus might not be absolutely impossible if approached from the standpoint of many combined and simultaneously running technologies. As a simple sketch, just to illustrate:

1. Nanotech and bio-nano-altered CO2 transforming atmospheric implants. (This is not intended to transform Venus, but instead designed as an initial step toward altering the planet from a "Level 1" (present state) to a "Level 2" – still highly toxic but different from previous state.)

2. At the same time, ground implanted systems that receive organic carbon raining toward the hot surface preventing carbon dioxide from being liberated again. (This is the magic part because I have no idea how that could be done.)

3. Simultaneously build very strong domed outposts housing automated systems and later inhabited by people. The structures are designed for research, monitoring and control of the above systems. And simultaneously:

4. The planet is prepared by a very powerful cooling mechanism. This is necessary so that CO2 enters a liquid state. Liquid CO2 must be maintained or aided by some process to remain at a pressure and temperature that tolerates a liquid state all the way to the ground. The construction in solar orbit so that it provides continuous temperature-lowering shade, a series of gigantic interlocking strips of material to block solar heat.

All the coordinated systems are related so as to accommodate emergent modifications, in other words, the phenomenon of the sum of all applied technologies being greater than the individual parts.

5. Massive, planet-wide applications to transform Venus into a dry, warmer Earth-sized world with an unbreathable atmosphere somewhat resembling Mars in its present state.

6. Introduction of water during the above processes. (Don't know how.)

7. Introduction on the surface (which is already inhabited by generations of domed dwellers) hybrid plants and animals to aid gradual transformation toward more Earth-like conditions.

8. Landscape beach resorts and open Venusian Tiki Bars for tourists.