On Sun, 25 Jul 2010 16:34:53 -0400, "Ed Huntress"
wrote:


"Don Foreman" wrote in message
.. .
On Sun, 25 Jul 2010 10:47:40 -0400, "Ed Huntress"
wrote:


wrote in message
...
On Jul 25, 2:47 am, "Ed Huntress" wrote:

This is different carbon?

Yeah, this is VERY different carbon. When you sequester vast amounts of
it
underground, for millions of years, and then release large quantities of
that carbon over a couple of hundred years, you wind up increasing the
CO2
content of the atmosphere.

When you sequester carbon via photosynthesis (the source of all of our
food), and re-release it in a cycle of a few years, at most -- unless
you
eat trees -- you don't have any significant effect. The effect is
steady-state, in which you have small amounts of carbon tied up over a
short
period of time and then re-release it.

You have an engineering background, Don. Don't play dumb. d8-)

--
Ed Huntress

If I capture a sample of CO2 and send it to you, neither you nor any
chemist you can hire will be able to determine if it was ever
sequestered, much less where and when.


That's irrelevant, and you know it. What matters is where it has been, and
for how long.

No. What matters is how much is being released to atmosphere by all
mechanisms vs how much is being removed from atmosphere by all
mechanisms. The only time constant here is the rate of concentration
change, which is proportional to the net increase of atmospheric CO2
per unit time divided by the total atmospheric volume.

CO2 from animal respiration doesn't magically migrate to trees while
CO2 from fossil fuel combustion goes directly to greenhouse. It may
be politically expedient to represent things that way, but that isn't
what happens.

I don't dispute that increasing the output by burning fossil fuels has
increased the load, but it's also true that reducing the amount
being removed by replacing vegetation with concrete decreases the rate
of removal -- again raising concentration.

In addition, increasing ocean temperatures can release huge amounts of
CO2 now held in solution.


It's more sensible to think of this as an accounting problem, and in
fact responsible scientists do look at it in that way by defining
carbon sources and carbon sinks.

Carbon sources emit carbon into the atmosphere. Those include animal
respiration, combustion, and various other sources.

Animal respiration does not ADD to the carbon in the atmosphere, in any
meaningful time frame.

Of course it does. Then other processes subract. If the subtractive
processes can't keep up with the additive processes, then atmospheric
concentration increases.

All meaningful "emission" of carbon by animals was
aborbed originally from the atmosphere and stored for, typically, a year to
a few years. All meaningful emission of carbon resulting from the burning of
fossil fuels was absorbed from the atmosphere millions of years ago. So
burning fossil fuels increases current carbon levels.

Burning fossil fuels releases CO2. So does animal respiration, forest
fires, and warming oceans.

Burning wood does not,
as long as you replace those trees.

Of course it does. If trees are replaced, then they will serve as a
CO2 sink but not until they are replaced and grow to size.

Carbon can also be
released from polar ice and ocean water with change in temperature.

Carbon sinks remove carbon from the atmosphere. Those include
solution in ocean water and captivation in ice, photosynthesis,
formation of carbonic acid by rain, formation of seashells and
eggshells that are primarily calcium carbonate, etc etc. Loss of
rainforest constitutes a major loss of carbon sink.

Very interesting, perfessor. But it has nothing to do with the question
raised, which I answered, and which you responded to: does human respiration
increase carbon in the atmosphere? It does not, over a closed cycle that's
mostly a few years in length.

If production equals consumption, there is no cycle length at all.
Whenever production exceeds consumption, concentration will steadily
increase.

Does burning fossil fuels do so? It does, over
a cyle that's millions of years in length. Thus, the latter can increase CO2
levels to prehistoric levels. The former cannot.

The fact that fossil fuel is millions of years old is immaterial. The
issue is that burning it releases CO2 now, which is in addition to
other sources like animal respiration, which makes the net release
rate greater than the present removal rate -- which is undoubtedly
less than it was 200 years ago.


If the amount of CO2 being emitted exceeds the amount being removed,
then the CO2 concentration in the atmosphere increases. If the
concentration in the atmosphere is to be controlled, then it's
necessary to consider all sinks and all sources to find ways to get
and keep them in equilibrium.

Ok, you go first. g I'll help you on the points that were raised he
Emitting CO2 from fossil sources increases the amount of CO2 in the
atmosphere. Emitting CO2 from people does not.

The amount of CO2 in the atmosphere increases if the amount being
released exceeds the amount being removed. Even if we eliminated all
fossil fuel combustion, if we reduce the planet's ability to remove
CO2, as by replacing vegetation with concrete, then the CO2 emitted
from people would increase the amount in the atmosphere.

We need to look at the whole issue, not just one aspect of it.


This bookkeeping isn't difficult to understand, but politicans and
zeolots often seem to find the notion of "balance" incomprehensible.

Not to mention the doctors of climatology who discuss the subject on this
newsgroup. g