SPS doubts

>--- In ssi_list@... "Arthur P. Smith"
>
>>Hi Babbler,
>>
>> I've been writing a bit about exactly this. Oil and gas aren't
>>
>going
>
>>to last the world much longer (unless they really go for the
>>
>dubious
>
>>tar-sands
>>
>Just curious, why would you call the Tar Sands dubious? They have
>been in production for decades; Alberta's Tar Sands produce 780000
>bbl/day of crude oil. More than half of the world's oil supply is
>in the Alberta Tar Sands, 1.3 trillion bbl.
>
Well, I'm no expert, but I've been told (A) they require natural gas to
convert to oil, which is itself in limited supply; without that the
processing is energy inefficient, and (B) while the reserves are
enormous in principle, practical extraction seems likely to be less than
10%, even with sufficient natural gas. That's still a lot of course. The
only reason they're actually in production now is government subsidy -
which is also behind ethanol and wind installations so far of cousre,
but could they really be a stand-alone energy resource?