search  current discussion  categories  kilns & firing - wood 

resending wood firer's footprint.

updated tue 8 jun 10


David on mon 7 jun 10

Lee Love wrote,
This is wrong in for several reasons:
2/3rds of a=3DA0=3D0A fuel tree is left
in=3DA0 the woods, much of it underground,=3D0A in the form of roots.

Can you give me a citation for the figure =3D0Aof 67% litter.

There are a lot of=3DA0 very helpful and interesting =3D0Apapers on the top=
ic o=3D
f wood acting as a carbon "holding company" .
apers/Monitoring%20and%20Measuring%20Wood%20Carbon.pdf=3D0A which is a pdf =
le. There are two tables at the bottom that are well =3D0Aworth a look.=3D2=
0 is another. Take a look at figur=
e =3D
These are two easy to =3D0Aunderstand studies. There are tens more I am loo=
ng at and none of them=3D0A suggest that burning of wood is carbon neutral.=
he studies are done by=3D0A researchers looking into questions that differ =
study but none of =3D0Athem see cutting wood as an exercise in putting a l=
tle=3D0A in the bank and being able to take it out later. This is the=3D0A =
c model being offered by most wood firers.=3D20
The question of if =3D0A"waste" wood is carbon free is addressed in the Car=
n and Forests paper=3D0A I linked to above. It clearly states there is abou=
t =3D
a 20% long time =3D0Acarbon sequestration gain in converting litter to chip=
s =3D
and then making =3D0Aproducts out of them.=3D20
The idea that oil derived fuels or coal should=3D0A be kept in a carbon seq=
stered state, not burned, but that somehow =3D0Asince wood is renewable it =
OK to burn isn't supported by any data. =3D0AThe 2 papers linked to, 2 of =
ny, stress the time factor in determining=3D0A the effectiveness of wood as=
carbon sink.=3D20
Here is something from =3D0Aanother paper.
This is taken from a report compiled by a forest =3D0Aproducts company. One=
ould expect them to give a sympathetic ear to =3D0Acutting.
Begin cut and paste.

=3D0AMonitoring and Measuring Wood Carbon=3D0A=3D0A=3D0A=3D0AIt may take 15=
0 years fo=3D
r regenerating trees on =3D0Aeach=3D0A=3D0Acoupe to recapture carbon remove=
d duri=3D
ng timber=3D0A=3D0Aharvesting.End cut.
From a different source. =3D0AThis is from an environmental impact report.
Monitoring and =3D0AMeasuring Wood Carbon=3D0A=3D0A=3D0A=3D0AIt is impossib=
le for a b=3D
iomass power plant that=3D0A burns=3D0Aexisting forests to be carbon neutra=
l si=3D
nce any increase=3D0A=3D0Ain forest cutting negatively affects the current =
aseline=3D0Acondition of forest growth versus cutting and=3D0A=3D0Amortalit=
y. Fur=3D
thermore, it is the overall carbon =3D0Aemission=3D0Ainput rate into the at=
here from an energy=3D0A=3D0Asource that matters, because overall carbon =
uestration=3D0Arates can not be expected to increase to make up for=3D0A=3D=
eased carbon inputs. With biomass burning of =3D0Aexisting=3D0Atrees, the o=
ll sequestration rate may even=3D0A=3D0Adecrease because of the impacts on =
the =3D
forest, =3D0Acreating a=3D0Adouble whammy.
End =3D0Acut.
The total carbon =3D0Asequestered in a tree isn't equal to the carbon it ta=
s to plant the =3D0Atree and grow. The tree sequesters more carbon as time =
sses, peaking =3D0Aat about 75-120 years depending on the tree. The carbon =
ntent of a =3D0Atree is roughly 50% of weight. That is a lot of carbon to t=
ow out into=3D0A the atmosphere in one go. It is especially important to no=
that the =3D0Abaseline rate isn't going to magically increase just because=
rees were =3D0Aplanted to "offset" cut trees. Take a look at Figure 1 in th=
e =3D
second =3D0Apaper I linked to.=3DA0It seems the logic of wood =3D0Afirers i=
s that=3D
since oil and coal are final units in the carbon cycle it=3D0A isn't OK to=
urn them but since wood isn't a final stage unit is is OK =3D0Ato do what o=
wants with it. Wood has to be seen as a carbon =3D0Asequestering medium to=
nderstand its =3D0Afunction. It is sticks of carbon. There is a balance tha=
t =3D
is maintained =3D0Ain nature that can't be sped up or slowed down depending=
n the needs =3D0Athat are at hand.=3D20
My original post to the =3D0Alist was for data on wood, electricity and oth=
fuel amounts. I have =3D0Agotten data from a couple of people off line for=
as and electrical. I =3D0Ahave found a simple way of figuring the carbon fo=
print for wood if the=3D0A wood was prepared without producing any other ca=
on inputs. The carbon=3D0A output would be .5 of the input weight. The outp=
for gas and other =3D0Afuels is in some sense easier to figure as a lot of=
ork has gone into =3D0Athose calculations.
Back to preparing for my=3D0A next firing.Dave