Tap the liquid cee-oh-two
Hi Nick
If we could liberate some of the liquid cee-oh-two that your original "White Mars" theory proposed, then we could have a thicker and warmer atmosphere up and running pretty quickly. Do you still think there's a couple of bars in the regolith?
If the metabolic slowdown experiments on mice can be generalised to humans we might get by on less oxygen, and with a bit of gengenineering we might be able to fix cee-oh-two as carbonate in our blood like crocs. Then a habitable Mars might not need to be a "terraformed" Mars, just improved a bit.