[permaculture] carbon sequestration

Marimike6 at cs.com Marimike6 at cs.com
Thu Feb 28 10:55:30 EST 2008


Kathleen offers an interesting question:

"Has anyone done the calculations to figure out how much un-built-upon
green surface we need to re-absorb all the carbon we've flung up out of
the bowels of the Underworld? And what kind of surface works best?
(forest, grasslands, crop-lands etc.?) "

Fast-growing tree or shrub plantations like Paulownias would be the obvious 
bet. But here's the rub: you can't burn this stuff, or convert it to biofuels-- 
because then you defeat your purpose by re-releasing the carbon.

So you have to either use it as paper pulp, fiberboard or some such salable 
product... or till it under to nourish the soil. And I don't think this 
(tilling it under) will ever become a widespread mitigation technique... because land 
and ag-grade water will increasingly be at a premium in our approaching world 
of nine billion people. The land and water will already be spoken for to grow 
food and fuel.

In fact crop residues, like chaffs, sugar cane byproducts like pressmud, corn 
stover and almost any leftover plant material you can collect in bulk, are 
already being used in the development of novel, salable products, as opposed to 
going back into the soil. So I think one problem for the immediate future is 
going to be the gradual and progressive starvation of agriculturally useful 
soils of organic materials.

Here in North Carolina most agricultural soils are already tired and worn 
out, emptied of any organic fraction generations ago. 

Those new chaff-based products and substances that retain their character, 
like resins, boards and fabrics, will still hold their carbon. But increasingly 
I think we can count on a lot of acreage being devoted to biofuel crops-- just 
a way to recycle the carbon from airborne to airborne form, while extracting 
a bit of energy in between.

I just don't see any way a profit-driven economy is going to devote a lot of 
time and energy into growing weeds just to bury them in place. And I don't see 
the governments we currently have being willing to pay people subsidies to 
set land aside for such purposes.

What I would like to see is more land just being set aside, to grow natural 
stuff in place and not have to make anyone who's already rich a little bit 
richer. The pressure for real estate development is killing the planet just as 
much as the combustible fuel energy sector. 

Here's an example of what's happening right now. Take special note of the 
costs per acre, though, to buy up land and set it aside to just grow. This 
approach doesn't come cheap!

The Beaufort County Rural and Critical Land Preservation Program 

http://www.bcgov.net/public_info_officer/Rural_Critical_Lands/R&CL_Main.php

michael

   


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