[Terrapreta] numbers (edited, highlighted)

[David Yarrow]

Critical Numbers

Where Should Humanity Aim?

Folke Gunther, Tuesday, March 18, 2008
James Hansen and his associates are working on an article Target Atmospheric CO2: Where Should Humanity Aim?  

They conclude-to remove immediate danger of tipping Earth's life support system to a state considered no longer suitable for humanity-CO2 in the atmosphere must be below 350 ppm.

Today, CO2 in the atmosphere is 385 ppm.

Thus, the air already contains 74 Gt too much carbon.

Every year, 7 Gigatons more are released. 

So, even if all emissions-100%-are stopped in 20 years (don't ask me how), an additional  70 Gt more emissions will occur, leading to CO2 of 418 ppm.

If the seas are kind enough to suck up more-perhaps 400 ppm.

Such CO2 levels will likely push us far past several tipping points.  The resulting climate will not feed the population, not to mention potential floods.  This will result in total breakdown of current society.

So, if disaster threatens whatever we do, should we give up?

No.  There is one more possibility:  decreased emissions-combined with massive carbon sequestration-can back us away from ominous CO2 levels.  Possibly.

Incorporation of char to soil obviously has major a benefit-and many further positive effects: increased crop yields, reduced nutrient losses, renewable energy, regeneration of forests, and so on.

Shouldn't we start immediately?



ps. link to James Hansen's Target CO2  article:

http://www.columbia.edu/~jeh1/2008/TargetCO2_20080317.pdf

  ----- Original Message ----- 
  From: Folke Günther 
  To: terrapreta at bioenergylists.org 
  Sent: Tuesday, March 18, 2008 7:32 PM
  Subject: [Terrapreta] numbers


  In my blog, I have put together the figures on the necessary size of sequestration.

  What is evident, is that any method leading to a decease of ghg:s must be used, together with a heavy decrease of emissions. Any delay is perilous.

   

  -------------------------------------------------------------------------------  

  Folke Günther

  Kollegievägen 19

  224 73 Lund, Sweden

  home/office: +46 46 14 14 29

  cell:               0709 710306  skype:  folkegun

  Homepage:     http://www.holon.se/folke  
  blog: http://folkegunther.blogspot.com/
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