Climate models are a joke.  There are far too many variables to predict accurately how much or how quickly temperature will rise.  You just cannot make educated guesses on umpteen variables and expect to get to the correct answer.  Not only that, but so many variables are not even known, or change over time.  

And why don't they include the vast carbon sinks (forests, grasses) in Canada when they talk about our emissions?  That is the most glaring joke of this whole tax scheme. Canada actually is a net sink for carbon, not a net emitter so the gov't should be giving us money, instead of taking more.