The only way that thought experiment could make sense is if they had the technology to do that, but not the technology to escape Venus and get to Earth.
If you have the technology to do that, but don't have the civilization infrastructure to support it, then escape/colonization might well cease to be a viable option. A global warming catastrophe could well precipitate a collapse of global civilization, in precisely the initially slow, sneaking way which might catch a global civilization unprepared. The Romans knew things were breaking down, but the generation which was invaded by the Vandals didn't think it was quite that time yet. Global civilization might well kick the can down the road with building their sun-shield, then get caught with its pants down, when civilization starts crumbling, and it loses the industrial know-how to pull it off.
How about a downer Sci-fi story, where the closing scene is of a Flat-Venuser enclave surviving in a subvenusian tunnel, telling half understood mythological stories of the long dead Eloi and their plot to blot out the sun?
If you have the technology to do that, but don't have the civilization infrastructure to support it, then escape/colonization might well cease to be a viable option. A global warming catastrophe could well precipitate a collapse of global civilization, in precisely the initially slow, sneaking way which might catch a global civilization unprepared. The Romans knew things were breaking down, but the generation which was invaded by the Vandals didn't think it was quite that time yet. Global civilization might well kick the can down the road with building their sun-shield, then get caught with its pants down, when civilization starts crumbling, and it loses the industrial know-how to pull it off.
How about a downer Sci-fi story, where the closing scene is of a Flat-Venuser enclave surviving in a subvenusian tunnel, telling half understood mythological stories of the long dead Eloi and their plot to blot out the sun?