Re: Something to think on.

Deirdre wrote: 

Robert Peffers wrote:

Around the end of this week the consultation period for those big pylons is
due to end.
Here is a little something to think on meantime.

There is an estimated 200, (plus), billion tonnes of CO2 per an. added to
the atmosphere but just under 3% of it is man made.

During previous Interglacials there were at least 4 of them that were warmer
than today.

The Late Orcdovician Period had very much higher CO2 levels than we have
today.

During all those times there was not a single coal fire. furnace, gas fire
or diesel or petrol vehicle in sight.

Perhaps some of the Greenies would care to explain those facts away?, (but
probably not).


Presumably it was residual from the original reducing atmosphere...the primitive atmosphere is hypothesised to have been comprised of CO2, N2 and water vapour
as a result of outgassing from the interior...in short, all the oxygen in it would be bound up meaning it would be a _reducing_ atmosphere (chemically speaking) rather than the oxidising one we have today.

At some point, in theory, simple organic molecules in the form of amino acids, purines, pyrimidines, fatty acids, glucose and nucleotides formed, probably with the help of volcanic eruption and lightening. It's at this point that CO probably entered the atmosphere. In time, if those amino acids washed up on the beaches, they could have polymerised into polypetides (proteinoids, if you like) which, upon reentering water, became macro-
spheres.

These macrospheres then, over time, evolved to become the first primitive prokaryotes, some of which were photosynthesisers (the forerunners of modern algae)...
their metabolic waste product was free (unbound) O2 and into the atmosphere it went. Shortly thereafter you had the Cambrian explosion and life under the waves diversified beyond a sci-fi writer's dreams.

"Shortly" in geologic time, aye? If you were to chart it, it would look something like this:

4.6 billion years ago  Formation of planet
3.5 billion years ago  Oldest known fossils
2.5 billion years ago  Atmosphere becomes oxidising
1.5 billion years ago  Prokaryotes and eukaryotes
				develop.
0.7 billion years ago  Multicellular organisms emerge
0.6 billion years ago  Cambrian era begins

The atmosphere didn't suddenly go from no oxygen to the levels we regard as "normal" (roughly 20% or
so)...and there's no way of really know what the levels
were, but it can be assumed they built up slowly over time...so an "oxidising" atmosphere in this case, is sim-
ply one with free oxygen in it...1% counted as "oxidising"
back then (still does, now that I think of it...1% O2 in my anaerobic chamber is a disaster.)

The Ordovician you mention was the period which followed
the Cambrian and is when the first land plants seem to have appeared. This plants would have taken over where the algae left off and further modified the atmosphere by changing the redox characteristics through photosyn-
thetic respiration...in fact, it isn't until the Devonian ~370 million years back, that you have a large scale expansion of
seedless vascular plants on land and not until the Carboni-
ferous (~300 million years ago) that things _really_ took. (A good time to be a plant, I guess)

The answer isn't green _or_ brown, it's simply a function
of where the planetary evolution was back then. We didn't start out with free oxygen in our air, it took time to get that way so it's not surprising that during early eras when the atmosphere was still in flux, the CO2 levels were higher.

Deirdre

Thank you Dierdre. It seems that even though there is not one peer reviewed paper or study that seriously challenges the theory of man aided global warming, there are still some who wallow in their own ignorance. My what a long sentence I've just produced!
.

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