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Instantly terraforming Venus at the present times would only last no less a second due to the fact it's a too close to the Sun. You will need to dim out the star so that the habitable zone would shrink down the size of Venus' orbit.
Difficulties include the fact thatΒ the production of organic molecules from carbon dioxide requires hydrogen, which is very rare on Venus. Because Venus lacks a protective magnetosphere, the upper atmosphere is exposed to direct erosion by the solar wind and has lost most of its original hydrogen to space.
The habitable zone of the Sun is currently expanding at a rate of one meter per year because of it's increasing luminousity. So in a billion years from now, we would eventually end up becoming Venus.
Difficulties include the fact thatΒ the production of organic molecules from carbon dioxide requires hydrogen, which is very rare on Venus. Because Venus lacks a protective magnetosphere, the upper atmosphere is exposed to direct erosion by the solar wind and has lost most of its original hydrogen to space.
The habitable zone of the Sun is currently expanding at a rate of one meter per year because of it's increasing luminousity. So in a billion years from now, we would eventually end up becoming Venus.