[extropy-chat] Bill Moyers' Comments -GlobalEnvironmentCitizenAward

[J. Andrew Rogers]

On Jan 8, 2005, at 11:28 PM, spike wrote:
> Can this be produced?  A 10-15 year old eucalyptus globulus
> is about something over meter diameter and fifteen meters tall,
> so for single digit precision we can estimate it at 10 cubic
> meters of wood, so we would need 1E10 such logs.  Can we
> produce ten billion of these?  I think we can.  Imagine
> them on 20 meter centers, so a couple thousand of these
> can be produced on each square km, so a couple good sized western
> U.S. states, the obscure ones that aren't good for much
> of anything and no one ever heard of anyway (such as Wyoming and
> Utah) is close enough to a million square km there, two billion
> trees per generation of 10-15 years, it would only take
> 5 generations (50 to 75 years) to generate that 1e14 kg of
> carbon in the form of eucalyptus logs.


This won't work, at least not at these numbers.  Commercial 
gene-engineered eucalyptus in high-yield plantations generate 20 tons 
of eucalyptus tree per acre per year on the average high-end using 
7-year rotations, with a typical tree density of 1,000 trees per acre.  
2 billion trees at this density is 2 million acres and only 40 million 
tons of new plant matter annually.  At that rate, it will take 2500 
years to sequester 10e11 tonnes of carbon assuming a direct conversion. 
  On the upside, the total area required is smaller than most Western 
counties, and less than the total Federal land ownership in most of 
those counties.

The other, more problem is the water.   Your plan would require 
something on the order of 10e7 acre-feet of water annually -- the high 
growth rate is fueled by heavy water consumption -- and you'll have to 
find a way to deliver this to western states that have annual fresh 
water resource capacity measured in a few million acre-feet per year.  
None of the water districts in the western US have anything remotely 
resembling 10 million acre-feet of excess capacity unless one 
completely drains one of the major rivers.

Your best bet would probably be the midwest rather than the mountain 
west.  Far more water, and similar population density (though not 
urbanized like the West).  To make this work in 50 years, you would 
need to scale this up by a factor of 50 or so.  Quite a bit of land, 
and making water a true rate-limiting factor.

(Behold, the power of google.)

j. andrew rogers