I guess carbon sequestration isn’t totally speculative:
Under the plan announced [268KB PDF] in March, CO2 would be captured from an 860-megawatt gas-fired power plant to be built at Statoil’s Tjeldbergodden (Norway) methanol complex. CO2 emissions from the plant — 2–2.5 million tonnes (t) of CO2 a year — would be piped to Shell’s Draugen oil field and to Statoil’s Heidrun oil field, both off the coast of Norway, and then injected into subsea reservoirs to force oil to the surface. (The operators currently use water for this purpose.)
The companies say that this operation would increase energy production in Norway while lowering the country’s CO2 emissions. However, they also admit that their plan is "technologically and commercially challenging" and depends on "substantial government funding and involvement." They estimate the project will cost $1.19-1.49 billion. If they secure all the necessary funding and approvals, construction of the power plant could start in 2010, with the first CO2 being delivered as early as 2011.
A billion and change, running in 2011. Sounds good to me!