[War] Timeline thinking

[Dan Garcia]

> Disagree on ethanol. You'd be right on -corn- based ethanol, but not 
> sugar cane-based.
> 
> http://en.wikipedia.org/wiki/Ethanol_fuel_in_Brazil
> 
> I could see this being used as a big "reconstruction generator" in 
> Louisiana.

According to the Wiki article you cited, Brazil produces 14 Mm^3 of ethanol a year from 45000
km^2.  This is about 3.7 BGals of ethanol with an energy content of 82 x 10^15 J (~22 MJ/Gal) of
energy.  The US uses 320 million gallons of gasoline per day, or 117 BGals per year.  At an energy
content of 30 MJ/Gal, this is an energy content of 35 x 10^17 J per year, or 42 times the ethanol
production of Brazil by energy content.  The total land area of the US is 9.2 million km^2, of
which about 20% is arable (CIA WFB), or about 2 million km^2.  To produce the amount of energy
content the US consumes via gasoline, it would take 42 * 45000 * 0.5 (let's say American
agriculture is twice as good) = 950 thousand km^2 of land to grow enough ethanol for our own use. 
This is half the arable land in the US, and when the US exports only about 1/5 of what we make
(http://www.ers.usda.gov/AmberWaves/November03/Indicators/behinddata.htm from 2003), that means in
order to switch completely to ethanol, we'd need to kill our exports and decrease our own
consumption from domestic sources by over 35% (which, perhaps given the obesity situation in this
country, some might not think a bad thing).  If you want to just stick to a mix, that mix can't be
more than 40% of our needs, before cutting into domestic consumption (only cutting into exports). 
This all ignores likely effects on prices of food, which might hurt the low wage folk.  

More fundamentally, the US is 2% of the Earth's surface, so let's say we get 2% of the sunlight
coming in.  That's 1400 W/m^2 * 3.14 * (6400000)^2 = 1.8 x 10^19 W total = 5.7 x 10^26 J/year for
the whole Earth, or 1.2 x 10^25 J/year for the US as a whole.  This ignores albedo , which is
about 0.4, meaning only 60% of this will reach the surface, or 6.9 x 10^24 J/year.  It should be
noted that this will be off by maybe a factor of as much as ten, as I have neglected seasonal
considerations and all that (I'm being overly simplistic, and I'm not sure which way it would
affect things).  Now this is still 2x10^6 times how much the US uses in terms of gasoline.  But
again, arable land is only 20%, and the plants won't be perfect converters of sunlight energy to
ethanol energy, in fact they'll probably be not very good at all.  And then we need to eat, and
all that.  All told, the US energy use in 2005 was about 10^20 J (that is fossil fuels, nuclear,
wind, etc... not food and such...)  For food, well assuming a 2000 calorie diet ( 8MJ/day ) and
300 million Americans, that's 8.75 x 10^17 J/year.  This will be something of an under-estimate
(obesity doesn't happen at 2000 cals a day... :) ), and there may be factors such as efficiency of
the whole plant-to-factory-to-mouth-to-cell process, which may be quite low.  Basically, the only
real hope of energy independence is to find a large source of stored energy (fossil fuels are
basically energy stored up from the Sun and Earth over millions and millions of years).  The only
source that comes to my mind is hydrogen via fusion (which is still decades off).

> 
> > The developing world remains developing technologically.5-10 years 
> > behind the developed world for the most part, though in more 
> > prosperous parts of the developing world, wireless broadband will 
> > find a place (it's much cheaper than laying down wires).  Cell 
> > phones continue to be big in the developing world.
> 
> This works, though I am dubious re wireless broadband.

The idea re wireless broadband and the developing world is that if I had to guess it was going to
make it somewhere, it would be there.  There isn't the big wired telecom system that we have in
the West, built over the past hundred years and reaching right up into everyone's homes.  So it
would be cheaper to just set up a wireless point to cover a few sq kilometers, and have fun.  Of
course, there are spectrum issues there too, just not as big as in the West.  The one other thing
which just occured to me which could compete in a big way is that there's been a good amount of
work on broadband over power lines.  If this gets worked out pretty well, that could be the method
of choice for the developing world.  But these are all things which will still be new even five
years from now in the best of conditions.

Dan