[Terrapreta] Fwd: Fwd: Global Carbon Cycle

[Kevin Chisholm]

Dear Lou

This is a very simplistic attempt to explain some of the factors 
influencing CO2 in the atmosphere.

Consider a "box" that represents the Biosphere. All Carbon in the 
Biosphere is involved with a "life process"... trees, algae, grass, 
animals, plants, etc. The carbon content in this biosphere box is in 
equilibrium, neither increasing nor decreasing.

Consider what happens when 1 unit of "fossil carbon" is added to the 
biosphere box as CO2. There will be an initial increase in the 
atmosphere. If there was space to grow, adequate sun, water and 
nutrients, and if the upper limiting value for CO2 was not exceeded, 
then it would be incorporated into plants, and other bio-forms. The 
atmosphere would then come to an equilibrium.

If you wreck a portion of the biosphere (cutting trees, killing animals, 
clearing land, etc, the system will return to the same equilibrium state 
that existed before the disruption. Total carbon in the biosphere would 
be the same, because none more was added, and none was removed. The only 
way to lower the carbon in the biosphere to get it back to its original 
level is to remove carbon from the biosphere. This can be done by 
converting some of the biomass in the biosphere into a weight of carbon 
equal to the weight of fossil carbon originally added.

So, to fit your query into the above framework...

1: It doesn't matter if trees are harvested, and allowed to decompose, 
in that no carbon is removed from the biosphere. There would be a short 
term increase as the tree rotted, but no long term net gain or net loss.

2: It doesn't matter if a portion of the trees are burned... the release 
is faster, but there is no net change in Carbon content.

3: Similarly, if the wood is used in construction, it is temporarily 
removed from the biosphere, but over the long term, it will be returned.

4: Similarly, with soil that is denuded of its organics... a short term 
spike of CO2 release, but no long term change.

5: If the land is built upon, it reduces the effective working space of 
the Biosphere, and the CO2 in the atmosphere will tend to rise, unless 
the plants can take up more CO2. However, there was no net change in 
biosphere carbon content.

6: If the land was allowed to return to forest, then the system would 
return to its original state.

7: If the land is converted to pasture, atmosphere carbon content would 
increase because there would be only a fraction of one year's growth 
sequestered as biomass.

8: Cow belches and termite farts don't matter either, in that they 
simply took carbon from the biosphere, and then gave it back later.

Thus, we see:
1: Carbon in the biosphere increases only when new carbon is added to 
the biosphere. (Fossil fuels, semi-fossil carbon such as peat bogs and 
methane hydrate, etc)

2: Carbon in the biosphere is only decreased when carbon is removed from 
the biosphere. (Charcoal buried as terra preta, compressed CO2 stored in 
  wells or caverns, etc)

3: Slower "recycling" of carbon that is temporarily sequestered in 
trees, or in construction materials, will tend to lower CO2 in the 
atmosphere, until such time as it is all returned within the Biosphere 
as a lifeform.

The bottom line is that if some people buy carbon credits and burn 
fossil fuels, there will be an increase in the carbon level of the 
Biosphere unless an equivalent amount of carbon was removed from the 
biosphere. Real carbon removal, not just "paper credits." The only way 
to maintain current levels of carbon in the biosphere is to remove a 
weight of carbon equivalent to that which was added as fossil fuel. The 
best that the present Carbon Trading system can do is maintain the 
present excessive levels of C in the biosphere. However, with Global 
Warming being evidenced as it is now, the present Carbon Trading system 
is institutionalizing a state of "much too little, far too late."

I hope that the above has some "elements of clarification".

Best wishes,

Kevin

lou gold wrote:
> Hello Again,
> 
> I have to admit that I haven't understood all aspects of these system so
> please let me off the hook of defending them all. I want to focus on just
> one:
> 
>>
>>
>> Consider a "mature" forest. By definition, a "mature" forest has 0
>> Annual Increment... there is no net gain or loss of biomass... the
>> forest mass lost by dying trees is made up for by new growth from
>> younger trees. If the trees are cut and used for building, then the
>> carbon content of the wood is sequestered in a building, and new space
>> is freed up for growth of new trees to take Carbon out of the
>> atmosphere. A mature forest does nothing to alleviate the Greenhouse
>> Effect, and as far as I can see, saving Mature Forests is a blatant
>> Carbon Credit Scam.
> 
> 
> It works this way. 20% of Brazil's carbon emissions is smoke from
> deforestation. Then there is the added emissions of whatever is released
> from the denuded soil. Then there is whatever is  burned for fuel. Then
> there is the life-cycle releases as products become wastes. The point is
> that the natural carbon sink retains its carbon much longer and in decay
> slowly contributes to ecosystem functions such as creating habitat,
> filtering water and building new soil. Indeed the quickly growing young
> plantation draws down CO2 much faster, but it is nowhere near the pace of
> the release in deforestation.
> 
> There are two processes we want to reward. 1) Slow the release into the
> atmosphere of carbon from wherever it is "sunk" and 2) retrieve from the
> atmosphere into new sinks in many forms (like terra preta). The thought is
> that it will take public policies to incentivize these processes.
>