Sure.
I think there are a couple of different pieces. The carbon budget model is obviously what we use for our national inventory, which tracks the emissions from forests and some activities in wetlands and peatlands and some activities in agriculture. The national inventory is great because it tracks, year by year, what's going out into the atmosphere and what's being sequestered.
One of the gaps—and I know that the scientists are anxious to continue to improve our national inventory—is that we don't capture all of the activities that cause emissions. There's new science, for example, that shows that when we have roads built into peatlands, that does cause significant emissions—even winter roads, for example.
We need to continue to improve the information that we have in our national inventory and to understand how these various activities are, in fact, causing emissions, so that when you put a price on carbon, you start to understand how different kinds of management practices are potentially detrimental, in some cases, in reaching our climate objectives and making good economic sense. I think that's one element that we need to think about.
I think the second piece is the work that's being done using the carbon budget model to look at mitigation pathways. One of the challenges with any modelling is that when they look at different pathways beyond the direct emission reductions that happen when we harvest less, there are all of these externalities or additional things that happen after that. It may be that it leaks and goes somewhere else, or in some cases if you say we'll substitute this product for another product, you have to make a lot of assumptions about how you're going to get that market to shift and make sure that those new goods are being used and that we're not just increasing our use of all products and therefore having more greenhouse gas emissions occurring annually, which we cannot afford at this point. We really have to turn things around.
In all modelling exercises, we have to be very careful about the assumptions that we make over time and place and about the types of assumptions we're making around demand and how well and quickly we can shift markets.
In general, I tend to focus more on where we're actually achieving direct emission reductions and contract those things, and I tend to get a little bit more concerned when we're putting a lot of emphasis on substitution when it's unclear how we're going to get there.