[extropy-chat] Bill Moyers' Comments-GlobalEnvironmentCitizenAward

spike spike66 at comcast.net
Sun Jan 9 21:58:56 UTC 2005



-----Original Message-----
From: extropy-chat-bounces at lists.extropy.org
[mailto:extropy-chat-bounces at lists.extropy.org] On Behalf Of J. Andrew
Rogers
Sent: Sunday, January 09, 2005 9:39 AM
To: ExI chat list
Subject: Re: [extropy-chat] Bill Moyers'
Comments-GlobalEnvironmentCitizenAward


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.


J. Andrew Rogers wrote:

>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...


James your numbers agree with mine better than I would have
expected since I was using ballpark numbers to one digit
without googling anything.  A square km is about 250 acres
and I was assuming a million square km, so thats 2.5e8 acres,
so with your numbers of 1000 trees per acre, thats 2.5e11 trees
and at 20 tonnes of plant matter per acre year, 2.5e8
acres is 5e9 tonnes per year (a square meter of wood
is close enough to a tonne for this level of calculation)
to if we need 1e11 tonnes of wood, thats 20 years.  So actually
your googled numbers are more optimistic than my wags.  Considering
that wood isn't *all* carbon, my original 50-75 yrs is probably
close enough. 



>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.  



Of course I do agree that it does have its costs.  It will
require us to divert the Columbia and/or the Sacramento
rivers, but that will need to happen anyway eventually, as
it did with the Colorado River (that one doesn't flow to
the sea anymore, it just ends near it).

I did google on land areas of Utah and Wyoming.  Together
they are only about half a million square km, and we would
need to leave some space for that school with the football
team, whats it called, Brigham Young U.  (Any school with a
football team is an actual school and should be preserved.)  
So it would take perhaps 50 years by James' numbers, or a 
century or two by mine, or if we really think there is a 
hurry we could toss in Arizona and New Mexico, two more
states which we are unclear on what they are actually good 
for, if anything.





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...




Ja but I have already said too many times on this list
that humanity must stop throwing fresh water into the
sea.  It looks cool and the salmon love it, but it that
practice is too stunningly wasteful to even comprehend.  
Fresh water is valuable; we have enough of it to do some 
really cool stuff if we choose to do it.

By sequestering carbon as logs in Arctica, we have an 
additional advantage of being able to reverse the carbon 
sink, should we later decide that it is a bad idea to draw
down the CO2 level in the atmosphere (which I suspect we
will eventually conclude).  I imagine that a CO2 level
around 500 ppm is optimal for most lifeforms, with a 
slightly higher oxygen level to go with it, perhaps 
22 percentish.

spike





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