
Canada's forests emit more carbon than they absorb - colinprince
https://www.cbc.ca/news/canada/calgary/canada-forests-carbon-sink-or-source-1.5011490
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hackbinary
I'm not sure what the author is playing at, but I think at the very least he
is trying to be a bit clever.

His argument is based upon that forest biomass is shrinking and therefore
forest are causing CO2 emissions:

"When you add up both the absorption and emission, Canada's forests haven't
been a net carbon sink since 2001. Due largely to forest fires and insect
infestations, the trees have actually added to our country's greenhouse gas
emissions for each of the past 15 years on record."

Forest only reduce CO2 when they photosynthesising, so if the forests are
being killed by fire or insects, then the forests are not ingesting CO2 but
are expelling.

They way this article is titled leads one to believe that forests are causing
the problem and that it is implicitly okay to be reducing forest biomass. I
think the title is misleading and disingenuous.

~~~
mywittyname
It's difficult to fit nuance into such a small title. And titles are not
supposed to convey the entire message -- if they did, what would be the point
of the article?

I understand where you are coming from, but that title is pointed, topical,
and expanded upon in detail throughout the article.

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airstrike
"Damage to Canada's forests makes them emit more carbon than they absorb"

T,FTFY

~~~
jfrankamp
And the forest fires and beetle vulnerability are not unrelated to current
climate change (at least in California last I read), so that might help close
the non-anthro-centricity argument they are using for different accounting
methods.

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GhostVII
I don't think this should be too surprising. Forests don't destroy carbon,
just store it in the form of trees. When the trees decompose, or burn down, it
is released again. So for a mature forest you would expect it to have around
net 0 emissions. As far as I know the main way a forest can be a carbon sink
is if it is expanding, which I don't think Canada's forests are doing.

~~~
mc32
Not sure about Canada, but my understanding is that for the US we’ve gained
forests compared to 50 or 100 years ago due to replanting, repurposing land
and having dedicated paper pulp tree farms.

~~~
elihu
Also fire suppression. That's become a bit of a problem, as the forests are a
lot more flammable now than they were historically.

~~~
Amezarak
That really depends on the state/region. You can see in this [1] report that
states like Florida and Georgia are burning millions of acres a year in
prescribed burns, while California burns a few ten thousand.

[1]
[http://www.stateforesters.org/sites/default/files/publicatio...](http://www.stateforesters.org/sites/default/files/publication-
documents/2015%20Prescribed%20Fire%20Use%20Survey%20Report.pdf)

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ainiriand
Well, then it is not the forest itself. It is the humans managing the forest,
if I've understood correctly.

~~~
sometimesijust
fta, recent fires and pests.

~~~
Varcht
Caused by global warming (human?), fta.

~~~
sometimesijust
The term "global warming" appears nowhere in tfa. That of course does not mean
it isn't the case but it does mean that you are mistaken.

~~~
Varcht
You are correct, I misattributed the top comment as part of the article, was
an honest mistake.

 __" Old growth forests tend to exist in a carbon steady state; younger,
growing forests tend to be net carbon uptakers. This situation is due to
natural disturbance regimes in forests, like fire and pine beetle, having
historically signifiant impacts in large part because of climate change."

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praptak
Peservation of mass holds as it always did. The forest only absorbs CO2 if the
total mass of the trees grows. For a mature foest this is usually not the
case.

~~~
asdff
Trees don't stop growing. Trees also die, fall to the forest floor, and a % of
the carbon is released as CO2 during decomposition but the remaining % is
retained as soil. The coal we mine to burn is from the retained % of ancient
forests. The oil we drill to burn is from the retained % of algae and plankton
that ended up trapped under rock and essentially pressure cooked into oil.

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csours
Semi-serious question: should a country have to account for volcanos in its
territory as well?

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tomp
Do volcanos emit CO2?

~~~
sometimesijust
Yes but they also emit ash which has cooling effects.

~~~
gotocake
More critically, they emit huge amounts of sulphuric compounds, which are what
really sick around and tend to cooling. Unfortunately when those same
compounds don’t reach high altitudes, you get a lot of acid rain. All told
however, their net effect is strongly cooling over the first few years, and
then milde cooling over longer time frames.

~~~
airstrike
Fantastic, thanks for the explanation. Can you please point me to a source?
Need to send it to my dad who taught me everything I know but has now turned
into a climate change denialist who says it's all a globalist / marxist /
leftist plot to make money off solar panels.

~~~
gotocake
Absolutely, and I wish you the best of luck in representing your views to your
father. I know how painful such a disconnect can be.

This is a good intro to the broad issue of volcanoes and climate:
[http://www.cotf.edu/ete/modules/volcanoes/vclimate.html](http://www.cotf.edu/ete/modules/volcanoes/vclimate.html)

A more in-depth treatment of sulfur aerosols in the upper atmosphere:
[https://en.m.wikipedia.org/wiki/Stratospheric_sulfur_aerosol...](https://en.m.wikipedia.org/wiki/Stratospheric_sulfur_aerosols)

Here’s a breakdown of all the gasses typically releases during eruptions and
their various effects:
[http://volcanology.geol.ucsb.edu/gas.htm](http://volcanology.geol.ucsb.edu/gas.htm)

If there’s anything else I can do, please don’t hesitate to ask.

~~~
airstrike
Thank you so much! I will send them all three. Just because you offered and
you seem so knowledgeable, he has also claimed the CFC damage to the ozone
layer was a hoax created to promote alternative refrigerants... If you have
anything on that I could use a link as well!

~~~
gotocake
My pleasure, and I have a great link that goes into the exact mechanism of how
CFC photochemistry destroys the ozone layer.

[https://scied.ucar.edu/ozone-layer](https://scied.ucar.edu/ozone-layer)

Here’s one with more technical analysis along with the exact chemistry:

[http://www.theozonehole.com/ozonedestruction.htm](http://www.theozonehole.com/ozonedestruction.htm)

Here’s a broad overview with historical perspectives from the American
Chemical Society:
[https://www.acs.org/content/acs/en/education/whatischemistry...](https://www.acs.org/content/acs/en/education/whatischemistry/landmarks/cfcs-
ozone.html)

I hope this helps.

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xeromal
I wonder if petrifying trees after they absorbed CO2 would help our emissions
problems?

~~~
vkou
Yes, it would.

But if you are turning trees into coal, and burying them, why on Earth are you
also digging up coal, to burn it?

Sequestration is going to be far more work then simply not generating
emissions in the first place.

~~~
maerF0x0
Tell me if this is incorrect thinking:

An advantage of sequestration is location. Something like you can emit the CO2
in a distributed manner (think car tail pipes) and then sequester it nearby
but in aggregate (think a facility just outside city limits)

~~~
vkou
The problem is that, in a market economy, like the one we live in, we can dig
up and burn coal much faster then we can grow and bury trees.

Coal can be mined for $30/tonne. That's 3 cents/kilogram. At that price point,
it's nearly free. How can you keep up with sequesteration, when you are
competing with nearly-free?

Sequestration makes sense when we are talking about an economy that derives
~5-10% of its energy from liquid fossil fuels, and everything else from
renewables. It doesn't make much sense when 50% of energy generation comes
from fossil fuels. It's just too labour intensive to make it work.

~~~
int_19h
Not just a market economy - a market economy that does not account for
externalities, like carbon emissions in the atmosphere.

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nakedrobot2
fun fact: many trees at around 30 years of age, become carbon positive,
releasing more carbon than they absorb.

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soVeryTired
TL;DR: stock vs. flow.

