This is the most important endorsement Biochar Land management has received!
I pulled out the the paragraphs that mention biochar from Jim Hansen's finished version :
P 227:
Carbon sequestration in soil also has significant potential.
Biochar, produced in pyrolysis of residues from crops, forestry,
and animal wastes, can be used to restore soil fertility
while storing carbon for centuries to millennia [84]. Biochar
helps soil retain nutrients and fertilizers, reducing emissions
of GHGs such as N2O [85]. Replacing slash-and-burn agriculture
with slash-and-char and use of agricultural and forestry
wastes for biochar production could provide a CO2
drawdown of ~8 ppm or more in half a century [85].
In the Supplementary Material Section we define a forest/
soil drawdown scenario that reaches 50 ppm by 2150
(Fig. 6b). This scenario returns CO2 below 350 ppm late this
century, after about 100 years above that level.
Supplementary material Page xvi:
Assumptions yielding the Forestry & Soil wedge in Fig. (6b)
are as follows. It is assumed that current net deforestation will
decline linearly to zero between 2010 and 2015. It is assumed
that uptake of carbon via reforestation will increase linearly until
2030, by which time reforestation will achieve a maximum
potential sequestration rate of 1.6 GtC per year [S37]. Waste
derived biochar application will be phased in linearly over the
period 2010-2020, by which time it will reach a maximum
uptake rate of 0.16 GtC/yr [85]. Thus after 2030 there will be
an annual uptake of 1.6 + 0.16 = 1.76 GtC per year, based on
the two processes described.
[85] Lehmann J, Gaunt J, Rondon M. Bio-char sequestration in
terrestrial ecosystems – a review. Mitig Adapt Strat Glob
Change 2006; 11: 403-27.
http://pubs.giss.nasa.gov/docs/2008/...ansen_etal.pdf
