Navitron Renewable Energy and Sustainability Forum

BIOMASS => General => Topic started by: ovonrein on February 04, 2011, 03:49:18 PM



Title: Yesterday's panic
Post by: ovonrein on February 04, 2011, 03:49:18 PM
I assume that everyone watches the BBC news religiously?  Good.  Yesterday, Huwie was trying to panic me with a story of droughts from the Amazon.  11bn trees dead, or something like this.  Apparently, this means that 1.5bn tons of CO2 can now not be turned into precious wood. 

It took me some time to understand the argument about the carbon-neutrality of wood, and why that was worth sponsoring.  Tree needs CO2 to grow, then releases the same when it decays.  Birth to cradle - big fat zero.  Burning is simply accelerated decay, result's the same - big fat zero.  I got it now. 

I have a question.  Take a perpetual forest, like the Amazon rainforest, or Epping forest, or whatever.  Isn't a forest that continuously regenerates itself as old trees die (and release CO2) whilst new trees grow (and bind CO2) perpetually carbon neutral?  And never capable of absorbing 1.5bn tons a CO2 made-in-Detroit?  And does it not follow that such forests can only contribute to a reduction in global CO2 levels if they are actively managed such that old trees are chopped down and turned into furniture before any decay sets in and releases CO2?

Any thoughts welcome.


Title: Re: Yesterday's panic
Post by: JohnS on February 04, 2011, 03:59:54 PM
Two comments.

First, if the decaying trees get buried and don't release the carbon dioxide into the atmosphere, the forest is a carbon sink.

Second, buried decayed trees end up as coal or oil.  When the carbon from them is released, by burning, why isn't this considered to be carbon neutral? 

John


Title: Re: Yesterday's panic
Post by: dhaslam on February 04, 2011, 04:28:42 PM
Burning coal or peat could be considered preferable to  burning wood  because  leaving the tree standing will absorb  CO2.     


Title: Re: Yesterday's panic
Post by: ovonrein on February 04, 2011, 05:11:28 PM
Buried decayed trees end up as coal or oil.  When the carbon from them is released, by burning, why isn't this considered to be carbon neutral?
Oh John - you go where angels fear to tread.  I thought that my opening gambit was provocative enough - I did not dare to take it one step further (not that I am an angel)...  

So are you saying that my theory is wrong coz all dead trees end up buried and stuff turns to coal?  And that perpetual forests do help in filtering out CO2 from Detroit?

leaving the tree standing will absorb  CO2.
Well, no tree stands forever.  They all die sooner or later...


Title: Re: Yesterday's panic
Post by: desperate on February 04, 2011, 05:54:11 PM
It's all down to timescales I guess, if you take a long enough time globally everything is carbon neutral, but if it is locked up via the rainforest for say a thousand years or more, while not strictly speaking neutral, it'll do for us. Carbon also gets locked up in forests, and then transported to the oceans via run off, and then it's gone for a long time, especially if it ends up in limestone.

Desp


Title: Re: Yesterday's panic
Post by: mespilus on February 04, 2011, 10:10:53 PM
Have you intentionally ignored the biomass of a mature trees' root system,
that is seldom harvested and burnt?


Title: Re: Yesterday's panic
Post by: ovonrein on February 05, 2011, 10:58:37 AM
Have you intentionally ignored the biomass of a mature trees' root system, that is seldom harvested and burnt?
You asking me?  Not intentionally - I am genuinely this ignorant.  This thread was just prompted by what I consider some of the worst news reporting available on any mainstream network anywhere in the world (well, Europe certainly).  I am just trying to get a handle on how realistic the 1.5bn tons of CO2 are.  Given how every other story on the BBC news is totally incoherent sentimental and sensationalist drivel, I expect this one will be too.