[pf] billion tons of carbon, not trillion (was: _very_ plain living.)

At 12:01 3/5/2001 +1200, I (David Mac) wrote:
>(3) True sustainability.
>... This last stage will have annual man-made emissions of carbon dioxide
of (from memory) 2 trillion tons, in contrast to 7 trillion tons now; not
none, but manageable by the biosphere. (Note that's a 70% cutback; the
Kyoto "agreement" is only a start, at 5-10%).
>

· The numbers were about right (for carbon, in a few years), but the units
should have been billion tons, not trillion tons. Flow, not stock.

  I had mistakenly remembered the units for _stock_ (of carbon) at and
above the surface of the rocky earth (including down to the bottom of the
ocean): 42 trillion tons (est.), most of which (38 T-tons) is in the
intermediate and deep ocean.

· The annual _flow_ of man-made carbon emissions is currently ~6.3 billion
tons.
{The above from p.85 of Worldwatch Institute's "State of the World 2001";
press release: http://www.worldwatch.org/alerts/010113.html }

· The other numbers were also about right.
Page 88 has:

 “.. to stabilize atmospheric concentrations of ... greenhouse gases at
levels that will avoid "dangerous anthropogenic interference with the
climate system"; scientists have not reached a consensus on the
stabilization level that would meet this objective. Because a doubling of
CO2 concentration would entail serious dislocatioons, the IPCC has also
considered a more aggressive stabilization target of 450 ppm [c.f. 280 ppm
pre-industrialization, and 368 ppm in 1999].
  According to the panel, achieving this goal would require cutting carbon
emissions by roughly 60-70 percent -- to about 2.5 billion tons annually --
by 2100, and eventually down to less than 2 billion tons per year.”

· If you do actually get into those numbers, you may wonder why a reduction
of 4 billion tons a year, when the stock is 40 trillion tons total, could
have the sort of effects predicted.
  I defer to the experts on the IPCC on this. I'll just say that it's a
finely-balanced system of capture and release, and that the last several
million years of earth's history shows convincing evidence that there is a
strong relation between carbon dioxide concentration and average
atmospheric temperature (see Fig. 5.4, p.86) - very strongly borne out by
the last 50 years compared with the rest of the millennium (at about the
280 ppm concentration of CO2).

· I say it's foolish to drill for _more_ oil for fuel; _reducing_ the
demand for oil by 2% to 5% a year, as some European nations are doing, is
the obvious way to go.

David.
(David MacClement) davd@ihug.co.nz 
http://www.geocities.com/davd.geo/index.html#top
************************************************

==^================================================================
EASY UNSUBSCRIBE click here: http://igc.topica.com/u/?aVxifP.aVx3Cb
Or send an email To: positive-futures-unsubscribe@igc.topica.com
This email was sent to: archive+pfvs@csf.colorado.edu

T O P I C A  -- Learn More. Surf Less.
Newsletters, Tips and Discussions on Topics You Choose.
http://www.topica.com/partner/tag01
==^================================================================