Answer: humans would need an A.I. to artificially create more than enough oxygen to survive
Explanation: well if the planet is 96% carbon dioxide and 4% oxygen then in the matter of days they would get really sick from breathing in excess carbon dioxide. so they would need an A.I to somehow make enough oxygen needed for everyone in the planet to survive, and they also wouldn't be able to drink water since there is only 4% of water because water is made of one oxygen atom and 2 hydrogen atoms.