Carbon in the soil can cause more global warming?

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Warming Could Free Far More Carbon From High Arctic Soil Than Earlier Thought

University of Washington (2005, December 5). Warming Could Free Far More Carbon From High Arctic Soil Than Earlier Thought. ScienceDaily. Retrieved October 26, 2008, from http://www.sciencedaily.com* /releases/2005/12/051205162830.htm

This has got me wondering if sequestering carbon (ala terra-pretta) may be doing just as much harm as if not more than good.

Limitations Of Charcoal As An Effective Carbon Sink

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*Bump*Odd figured I'd at least see some pretta-heads here.

[Essay]

Originally Posted by DFINITLYDISTRUBD

Limitations Of Charcoal As An Effective Carbon Sink

Yes, this has been briefly discussed somewhere here at Hypography before.
...but not right before the election.

"They found that when charcoal was mixed into humus...."
Well of course, if you're gonna be using soils already high in Carbon!

"Therefore, while it is true that charcoal represents a long term sink of carbon because of its persistence, this effect is at least partially offset by the capacity of charcoal to greatly promote the loss of that carbon already present in the soil."

"The study finds that the supposed benefits of biochar in increasing ecosystem carbon storage may be overstated, at least for boreal forest soils. The effect of biochar on the loss of carbon already in the soil needs to be better understood...."

See, this is all about forest soils. These soils are already fairly mature, high-carbon soils. Biochar would disrupt these soils if not used in some very specific way (to be determined).

Marginal Soils should be the focus for application of Biochar.
Restoring desertified lands, maintaining arable lands without the need for petro-fertilizers and herb/insecticides, and processing wastes while growing soil to soak up CO2 should be the focus.

This Swedish forestry experiment only serves to show that managing the microbiome is the key to the soil Carbon balance.
As they say, "...carbon already in the soil needs to be better understood...."

But they don't quite get the total significance of char:
"...charcoal represents a long term sink of carbon because of its persistence...." Yes, but also....

Though the char contributes, it is the new microbiome that is sustained by biochar that is the key to sequestration, not the char itself.


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p.s. Thanks for the bump!

[DFINITLYDISTRUBD]

This is both my point and not...
As you read through post after post here on char...you find that the char is not being used to rehabilitate desert or marginal soils necessarily...nor is it being fed to the soil as a solo additive but is as often as not mixed with various compost mixes etc. creating homes for bio-load (bacteria which decomposes goodies in the soil releasing co2 and or methane as a by-product.). As a fish-keeper I understand the balance of co2 and bio-load, Maintaining the balance in a tank is necessary because fish like to breath rather than warming issues but it does lend insight into how these things are interconnected.

Basically my point is that we may be eagerly rushing to char as a curative a little prematurely and it seems our lack of the complete picture may come back to bite us in the bottom if we over do it. We may find it is counter productive using a pound when an ounce is all the soil can stand...Of course I find most methods for producing char questionable at best as to how much benefit for the additional co2 released in the process as well....but that's probably another thread.

[Essay]

Yes, I see your points. ... and the exhaust part does go on different threads.

There is still much to learn about how char works, and how the microbiome works!

I think the thing to focus on is the biomass (microbiome) generated, and not the fluxes in respiration that occur as a biome is stabilizing. There are plenty of wrong ways to manage a biome and cause short-term net releases of CO2 or nitrates; but as long as the biomass is increasing or maximized, there should be a long-term net sequestration of CO2 (and nitrogen).

...especially for reclaimed desertified areas!

If these carbon sinks are later allowed to dry out and the biome die, then much of the carbon (except the char) would be released.

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[freeztar]

Originally Posted by DFINITLYDISTRUBD

Basically my point is that we may be eagerly rushing to char as a curative a little prematurely and it seems our lack of the complete picture may come back to bite us in the bottom if we over do it. We may find it is counter productive using a pound when an ounce is all the soil can stand...Of course I find most methods for producing char questionable at best as to how much benefit for the additional co2 released in the process as well....but that's probably another thread.

When a material is 'carbonized' (ie charred), it loses all, or most, of its constituents. The carbon becomes basically inert (does not react easily with outside chemicals). Char is such a good bed material for micro-biological growth because it is porous and protective.

The benefit of locking char in the soil is that you are taking once-breathing biomass out of circulation and recycling it as a negative CO2 feedback loop. All of the Appalachian states (and indeed, most of the US) was historically and naturally managed by fire. Evidence for this is abundant, both in plant associations and soil assays.

So, char is still great. But, as always, too much of a good thing is bad.

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To touch on the original article:

"We already know the Arctic climate is warming, and as it warms the depth of the permafrost is lowered. As that happens, more carbon becomes active and can be converted to carbon dioxide, one of the most abundant greenhouse gases in the atmosphere," Horwath said.

She noted that there is disagreement among scientists on just what the added warmth might mean for the high Arctic. Some say warmer climate will produce greater plant activity to absorb more carbon. Others say the overall carbon absorption is decreasing as the permafrost retreats.

The gorilla in the room is actually methane in this case. Methane is 20x more powerful a GHG than CO2. When the frozen wetlands (tundra) begins to thaw, it can create a runaway effect that can make human contributions look petty.

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*bump*
My methane output is the major contributer to GW