[Terrapreta] CO2 rising

[Brian Hans]

Sean, I dont understand your question.
   
  http://chainreaction.asu.edu/ecology/digin/carbondioxide.htm   <-------A laymans read on the topic. 
   
  There are many ways carbon exchanges on the planet and as the Biopact pointed out, forests are a relatively fixed number. Wetland, soil, oceans, lakes...there are many other sinks of carbon that actively gas exchange CO2 with the ATM. http://www.geology.iastate.edu/gccourse/chem/carbon/text.html
   
  A browse thru that link of data will find that there are many relationships of CO2, plants and a-biota. This is not as simple as you are making the carbon cycle sound. 
   
  By the way...as I read it again, a quote sticks out;
  Carbon dioxide is a friendly gas: at atmospheric concentrations, even double the present amount, it is not harmful to humans, since it is odorless, colorless, and does not react in the human body. And plants grow more vigorously in enriched CO2 environments, so why do we raise the concern about its increase? A significant characteristic of carbon dioxide is that it has a very long effective lifetime in the atmosphere. Figure 3 shows atmospheric concentration excess as a function of time. This graph provides an answer to the following question: If we put one extra kilogram of carbon dioxide into the atmosphere, how quickly will the atmospheric CO2 level return to its original level? This curve shows that 60 years have elapsed before half of the initial kilogram is removed and about 200 years elapsed before two-thirds of the initial amount it lost. The lifetime of carbon dioxide in the atmosphere is obviously very long. This means that large amounts of carbon dioxide
 presently being put into the atmosphere by burning fossil fuels and deforestation will, on average, be around for many decades.
   
  CO2 is not the limiting factor 365days of the year in the boreal forest... temp and water likely trump CO2 most of the time. No matter how high ATM CO2 is in Wisconsin on Feb 1st, there isnt much CO2 being fixed by the pine trees out back. But in the heat of the summer, when the plant cannot get enough water VS sunlight, they have to close the stomata to save H2O. In this particular case, the higher the ATM CO2, the better the closed stomata plant can gain access to its main building block food, CO2.  Same for algal blooms. Same for C4 grasses on certain days. Tropics have longer growing seasons so are less affected by temp and thus benefit from the increase ATM CO2 plant growth much more than the farther north/south you get. 
   
  Brian Hans 
   
   
   
   
   
  

       
  Forests cover roughly ~1/3 (9.5%/29.2%) of the land surface.  Here is the question ... When the Biopact article says forests are putting more carbon into the air than they takes out, and forests "hold" 89.3% of the standing carbon, then who is convinced that plants take up the excess CO2?
   


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