Okay. It's just important for us to know the full cost accounting, I suppose, of how much is actually being put in the ground versus how much total net is being saved from going into the atmosphere. I couldn't see those numbers in your brief, but they're important for us to understand as we talk about these policy options.
To Dr. Keith, have we any concept of what a tonne of carbon dioxide costs in this country right now--or will cost in the next few years?