CO2 gives us that greenhouse effect thing.

Try to grow crops or live outdoors without it, see how that works for
you.

"Rodney Blackall" wrote in message
...
| In article ,
| Bob Brown . wrote:
| CO2 gives us that greenhouse effect thing.
|
| Try to grow crops or live outdoors without it, see how that works for
| you.
|
| Have you not noticed that greenhouses have windows that can be opened when
| it gets too warm?
|

There is not a high level of CO2 in our atmosphere. Compared with Nitrogen
and Oxygen it exists as a "trace" gas. Its concentration is measured in
parts per million as the proportion by volume is well under 1%. Many other
planetary atmospheres have much larger concentrations of CO2 than ours,
which has been largely cleared out by plants and by geological processes.

Nor is CO2 the only greenhouse gas. Apart from the infamous CFCs, which are
now being dealt with, major contributions also come from methane (also a
trace gas) and water vapour (rather less so but still a minor constituent of
the atmosphere compared with the "big two").

Critically, it is a matter of balance. Without greenhouse gases our world
would be an ice house - and indeed it is now believed by some that this has
happened in the past. The temperature of the planet is a balance between
radiation coming in and going out (the "greenhouse effect" in the one in
your back garden actually has very little to do with radiation balance and
much more to do with the presence of the glass stopping the warm air inside
escaping). This is a very sensitive balance, which is why small changes in
the concentrations of trace gases in the atmosphere can have such an effect.

The balance is not helped by various feedback effects. One is that any
warming will increase the concentration of water vapour in the atmosphere by
evaporation from the warming oceans. This will in turn increase the warming
that water vapour produces.

An even more worrying effect is the possibility of mass methane release by
warming of deposits of this gas held in a metastable "hydrate" form in
regions of the sea bed, also locked up in some permafrost regions. If these
hydrate deposits become unstable and release their contents, this would
generate a level of warming which would put anything we have currently seen
in the shade. I have seen a documentary about the Permian extinction, which
was stated to involve a CO2 and other gases release by major volcanism which
raised the earth's temperature by 5C. This alone could not explain the
extinction - until research showed that this destabilised the methane
hydrates present on the world's ocean floors at the time, contributing
another 5C. The combined 10C warming extinguished most life on the planet.

This is the trouble with concentrating on CO2 alone. It can cause a lot of
trouble, but if other effects (like the methane release) are triggered, a
few degrees on our temperatures and a few feet rise of sea levels could
suddenly escalate into a critical condition threatening not just us but
nearly every other living thing on the planet. If that documentary I saw
has more than a grain of truth, it has happened before. Whatever we allow
to happen to the CO2 concentration in the air, we cannot - if we want to
pass anything on to future generations rather than selfishly live for
today - allow the situation to reach the point where those methane hydrates
go.

A long term effect is the steady brightening of the sun as it burns its
nuclear fuel and helium accumulates in the core. This is on a totally
different timescale to our current efforts, but over hundreds of millions of
years will take effect. The level of carbon dioxide that existed in our
atmosphere before industry got going was essentially a balance between its
removal by living things and excessive cooling if too much went.
Essentially, the life on this earth uses the carbon dioxide (and related
gases) level as a "thermostat" to hold the temperature at a level at which
life can survive. Eventually, (a thousand or two million years from now)
the brightening sun will reach a point at which it is no longer possible for
living things to clear enough greenhouse gases from the atmosphere to
maintain the current balance. A look at our neighbour which at the moment
shines so brightly in the west after sunset gives some idea of what will
happen after that point is passed.
--
- Yokel -
oo oo
OOO OOO
OO 0 OO
) ( I ) (
) ( /\ ) (

"Yokel" now posts via a spam-trap account.
Replace my alias with stevejudd to reply.

"Yokel"

Critically, it is a matter of balance. Without greenhouse gases our world
would be an ice house - and indeed it is now believed by some that this
has
happened in the past. The temperature of the planet is a balance between
radiation coming in and going out (the "greenhouse effect" in the one in
your back garden actually has very little to do with radiation balance and
much more to do with the presence of the glass stopping the warm air
inside
escaping). This is a very sensitive balance, which is why small changes
in
the concentrations of trace gases in the atmosphere can have such an
effect.

This sensitive balance is sometimes disturbed by cosmic cataclism, volcanoes
and people. The trace gases are the nutrient for plants and come back to the
air as the biomas smoke (the fossil is also biomas). So I have the question.
Does the desulphuration of the biomas gases disturb this very sensitive
balance or not?
S*

"Rodney Blackall"
...
In article , Szczepan Bia³ek
wrote:

[Snip]

This sensitive balance is sometimes disturbed by cosmic cataclism,
volcanoes and people. The trace gases are the nutrient for plants and
come back to the air as the biomas smoke (the fossil is also biomas). So
I have the question. Does the desulphuration of the biomas gases disturb
this very sensitive balance or not? S*

A major source of sulphur is the oceans. Until we exterminate the flora of
the seas they will release organic sulphides (sorry, forgotten its exact
nature for the moment) which gradually oxidise into SO4--.

A significant background to "acid rain" production is this source (I
helped
find it so I should know). The sulphate ions also help make condensation
nuclei to augment NaCl ejected into the atmosphere by the bursting of the
little bubbles that make up foam.

More wind=more foam=more CCN=more cloud=change in albedo=change in
radiation
budget ... (it gets complicated see, and anyone trying to get far without
a
good, complex, ocean-atmosphere coupled model with lots of
multi-disciplinary backup can get up a crocodile infested creek with a
dodgy
paddle).

In such model should be also the fly ash content. A significant background
to "acid rain" production is the lack of the fly ash in the air. As we know
the electrical filter were introduced first and next the desulphurisation.
The problems (acid rains and warming) appear in the same sequence. Am I
right?
S*

"Rodney Blackall" wrote
...
In article , Szczepan Bialek
wrote:

In such model should be also the fly ash content. A significant
background to "acid rain" production is the lack of the fly ash in the
air. As we know the electrical filter were introduced first and next the
desulphurisation. The problems (acid rains and warming) appear in the
same sequence. Am I right? S*

There is a big difference in the time between acid rain starting and the
time its effects are noticed.

In gardening it takes about four years (if no limestone in the soil).If we
assume that the acid rain started in Sveden immediately after installing in
UK and Norway the dedusting equipment we have enough time. See also that:
http://in.answers.yahoo.com/question...0043751AA69AIb

I doubt fly ash ever went high into the atmosphere. It's the other
particulates of industry and forest burning that load the atmosphere with
haze that raises the albedo.

I have seen a next factor. In nature all wildfire were outdoors and energy
from open flame were radiated in space. Now all is burned indoor and no open
flame so the radiation is lower. It is also a small contribution to warming.
To restore the natural conditions we must at least load the atmosphere with
proper particulates. May be that very clean air is not the best solution.
S*