Quote:Hmm... I think I might have a better idea - a variant on Drak's.
The shortest route I can think of immediately would be to use a sunshade and wavetech radiators or heatsinks of some sort, cut off the energy input and start sucking away as much heat as possible. Once the CO2 starts to freeze out, the Senshi can release the Crystal Milennium goo, start coverting all that dry ice into diamond & oxide/carbonate rocks. Still leaves the spin and water problems, but the Castles can handle both of those easily enough. (Imagine, once the Castles spin Venus up to a proper day-night cycle, they detach, head for the Kuiper and grab a nice cometary body a little larger than Pluto. Haul it back and start stripping it for water.)
First step is to build the Castles - call it twenty, total. Could well be more but I don't have the energy to look up the number for even coverage at the moment.
For a decade or two they act as bases for earning the cash for operation and expansion, and, at the same time, charge up for The Spin. Once that's over, the six fully inhabited 'primary castles' stay in place while the elevators are constructed... and the rest, the ones that were more like giant drilling platforms than actual towns, are stripped of much of their equipment before turning on their drives, opening their doors, and turning their internal thermostats down below the freezing point of CO2.
Being as they're... rather larger than a LNG tanker, this should speed up the process of straining the atmosphere considerably. Eventually, this will get the air to what's considered an 'acceptable' point, and they stop hauling dry ice and go off in search of suitable comets or whatever.
Overall time taken, at an utterly wild-assed guess... fifty, sixty years or so.
Ja, -n
===============================================
"Puripuri puripuri... Bang!"