Maybe I could start, and Mr. Lambert and Mr. Wright can add.
I believe there are three opportunities to reduce greenhouse emissions from the oil sands. Mr. Lambert already referred to the 40% reduction in greenhouse gas emissions per barrel since 1990. That's significant. Frankly, it's far greater than what's been achieved on the downstream use over that same period of time.
Looking forward, I think carbon capture and sequestration will play a role. I think we'd all acknowledge that there is a gap in terms of the economic viability of those projects at this point in time, but I think they will have application.
A project in Weyburn that's operational today is recovering incremental crude oil from recovery and transport of carbon dioxide to that field. That is an opportunity, but I think it's fair to say it will have focused applications.
The second one is improving the efficiency of our service operations. That's where a lot of the benefits have come from up to this point.
Third, and I think probably most importantly, in terms of the mix of future production from oil sands and the increasing importance of in situ, I think there are tremendous opportunities to, in effect, improve the efficiency of the extraction process. Mr. Wright talked about one of those; many others are being looked at. I think we understate the potential improvement opportunity from the in situ part of the oil sands business that will come from more efficient extraction. Whether that comes from use of solvents, lower temperatures, steam, or innovative recovery processes such as Petrobank is applying, I think there is tremendous opportunity there, and we should not understate its potential going forward.