There have been all kinds of estimates for costs for measures of this kind. As you know, the national round table has looked at this. More recently, the Pembina Institute and the Suzuki Foundation have looked at this and come up with different types of cost estimates.
The point I'd like to make, which doesn't come out very often in this debate, is that the cost of acting depends on the measures you choose to do the action. So pick a target, any target. You can generate all kinds of cost estimates. If you do silly things to try to reduce emissions, it's going to be very costly because you're not going to be getting a lot of bang for your buck.
It seems to me we're really focused on this one-to-one relationship: here's a target, here's the cost. I would say to you there's an intermediate step. The choice of mechanisms or the policy instruments you're going to use to achieve the target are really important in determining the cost. We don't have that discussion often enough.