[extropy-chat] Global warming news

spike spike66 at comcast.net
Sat Mar 25 22:55:26 UTC 2006

> From: extropy-chat-bounces at lists.extropy.org [mailto:extropy-chat-
> bounces at lists.extropy.org] On Behalf Of Martin Striz
> Sure it does.  When leaves grow on trees, that also fixes carbon from
> the atmosphere, so the effect of yearly cycling of leaves tells you
> how much of an effect on CO2 that much biomass has, and it takes into
> account both plant metabolism and fixed mass...

Leaves?  Really?  I suspect the total biomass of leaves can be neglected in
this calculation, these being small and temporary.  The biomass fixing
scheme I have in mind uses conifers, in which case the total mass of
"leaves" or needles in this case is negligible.

>  Now granted, the
> fraction of mass that leaves make up is, let's say as a conservative
> estimate, 1/10 that of the entire tree...

With conifers the fraction would disappear in the noise.  The resulting wood
is hard and durable.

>...  You couldn't plant it on the surface of
> the earth (taking into account arid and cold zones)...

The global warming people keep promising us we will eventually lose the cold
zones, and we can do something about the arid part: pipe in water.  Looking
at the globe, I see huge stretches of territory in northern Canada and
Siberia which may become prime habitat for pine forests, if it warms a few
degrees celcius.

> >  Recall that the entire atmosphere
> > has a mass of about 10 meters of water over the entire globe, so the 380
> ppm of carbon dioxide equates to a layer of water 4 millimeters depth.
> You don't want to fix all the carbon dioxide or you'd suffocate plant
> life.  Also, I don't know where you're getting this 4 mm figure from.

The carbon dioxide is about 380 parts per million by mass.

(10 meters)*(380/1000000) ~ 4 millimeters.  

So the entire mass of carbon dioxide in the atmosphere is equivalent to a
water layer about 4 millimeters depth, or about 4 million kg per square km.
Isn't that much is it?  Or you can think of it as a layer of water a little
over a centimeter depth, or a layer of wood a couple cm.  (BOTECs are
usually only one digit of precision.)  It is easy to imagine producing
enough wood to be equivalent to a couple cm thickness.  Using the previous
calculations assuming 2 meter diameter trees spaced on 40 meter centers
(forgetting about the small fraction in the temporary and cyclic leaves) a
typically spaced forest would carry 70 million kg of carbon per square

So my BOTECs tell me all the carbon dioxide in the atmosphere is about 4
million kg per square km, and the global warming people are saying thats
about a third again too much, so a million kg per square km excess.  But a
typical forest (as estimated by me, and I am open to countersuggestion) is
carrying 70 million kg per square km in tree trunks alone.

Martin, what am I overlooking here?  I have ignored the wood biomass on the
ground in the form of rotting trees and all the carbon that I already know
is down there.  Looks to me like every square kilometer of new hardwood
forest we establish will soak up about 70 square kilometers of industrial
excess CO2.

This sounds to me like a better idea than pulling down CO2 using plankton
blooms in the ocean, since we have the option, should it become necessary,
to dump the CO2 back into the air, if for instance we suffer global cooling,
or we decide we like it warmer.



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