[permaculture] trees and CO2

Marimike6 at cs.com Marimike6 at cs.com
Fri Oct 21 10:21:22 EDT 2005

"I just recently read the summary of a NASA study that said rainforest 
deforestation causes little of the rise in global CO2 levels. This totally 
contradicts everything I've heard before. I don't know of a good source of information 
on this topic."

Good question, Rain. Two answers come to mind.

First, most CO2 sequestration takes place in the oceans, where phytoplankton 
(microscopic plant life) consume more than do all the green plants on the 
earth's surface. But there's more to it than that.

It's not the existence of plant life that consumes CO2, but plant growth. A 
mature rain forest has a pretty stable metabolism, growing and dying at a slow 
pace. Cut it down and replace it with crops, as was done in the Mato Grosso, 
and you could even come up with a net gain in sequestration, since the idea is 
to grow crops at a fast rate.

A lot depends on what you do with the brush you clear. Burn it and there's a 
tremendous release of stored energy. This really does pump CO2 into the 
atmosphere. What you have done is to oxidize all the carbon stored in the forest, 
and carried it airborne as smoke.

If instead you sold the logs and tilled the ground-up slash back into the 
soil-- which of course they don't do down there-- you wouldn't have much of a CO2 
gain in the system. What you'd have instead is bare dirt, ready to plant.

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