Quoting Dr Guy, reply 12
And the added bonus is no one would complain about global warming!
I read the Mars series by Kim Robinson. One of the themes is how eco-terrorists rise up against the terraforming of Mars. "we must get rid of the nasty green stuff sprouting up everywhere!"
I was going to mention the Mars trilogy, but you beat me to it. Recommended reading for anyone interested in space colonization, terraforming, or alternative socioeconomic paradigms.
Terraforming Venus might be doable, but we wouldn't be able to actually go there until very late in the process. In contrast, we can go to Mars now and build underground colonies or cover the canyons while we work on "polluting" the atmosphere to make it warmer and thicker.