A possible solution?
We already ship crude oil all over the world in big tankers from the few places whilch can supply it. Well, there are certain places on earch which can supply vast amounts of renewable energy.
Deserts are vast wastelans, virtualy uninhabitable by mankind and therefore mostly uninhabitted. Large solar arrays (probably solarpowered steam turbines, or something similar, would be preferable to photovoltaic cells with current tech, but this could change in future) could be spread accross these wastelands, and the energy used to process the CO2 & Water (obviously either the water or elecy must be transported, as theres little water in the desert). This can then be shipped back to "civilisation".
There are also places with a lot of geothermal power available, which could be harnessed (although I would be worried about what effect sucking vast amounts of energy out of the earths core would do). There are large rivers, very windy sites, and other similar phenomenon all over the world.
I think the desert idea is great myself, using land which is unusable for any other purpose, and this way you just transport from, say, the sahara instead of the middle east. Negligible difference in transport (the main difference being you must transport both ways, however the fuel is also already processed rather than in need of refining, which may offset the difference).
Just my two pence worth (I've been thinking about it for a while, for production of hydrogen, but hydrogren + extremely high temparatures doesnt sound like the best plan to me :S )


