I always thought that before we engage on very expensive CO2 reduction thingies, we should reduce air pollution in general, which gives us many immediate benefits. One thing to do is a congestion charge, which they do in London. Now, they want to increase the charge for ridiculous cars (for the city!). Naturally, Porsche is screaming.
In Toronto, we should have a 400 series congestion charge, and nail the trucks and race cars. This is far better than building stupid bird-killing wind farms, or thinking about shoving mobile CO2 into the ground, where it's bound to come back. (Actually, expensive sport cars are very efficient when run at the speed limit on the highway -- ha, ha... as if they ever do!)