Actually, with emissions trading, emissions ARE reduced. You get a quota for how many emissions you are allowed. If you emit more than your quota, you are penalized unless you buy more from someone who then agrees to emit less than their quota to make up yours. It rewards conservation by making the amount you conserve a tradable asset with a price attached.
Lets say you buy a coal plant. Then you shut it down and sell its emissions quota, piece by piece, to SUV drivers. You profit. The SUVs didn't have a quota in the first place. Global emissions drop by the amount the coal plant you shut down, would have emitted. In effect the SUV drivers pay to shut down the coal plant.