I don't know the methodologies that were used to calculate that number. As I said, it's a study that was done by the Bureau of Land Management, which tried to capture some of these uncertainties that exist in the life-cycle assessments around wood products, in particular trying to capture some of those upstream impacts.
One of the concepts is a notion of a carbon debt, for example. If you cut a primary forest and replant it, even if we assume that you get 100% regrowth, you're not returning to a primary forest and you get a net loss of carbon. There's a carbon debt there, and that debt has to be calculated within the overall life-cycle profile of the wood products that come from that harvest.
They've tried to factor in some of those considerations—soil, carbon impacts, that sort of thing—to come up with a more realistic account of carbon impacts that doesn't just assume that every tonne of carbon you take out is going to be replaced by a new tree that grows in its place.