Re: Snowball Earth


"Alastair McDonald" <alastair@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx> skrev
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"Carsten Troelsgaard" <carstenNOSPAM.troelsgaard@xxxxxxx> wrote in message
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"Alastair McDonald" <alastair@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx>
skrev
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"SBC Yahoo" <atilla.the.hun@xxxxxxxxxxxxxxxxx> wrote in message
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Yes, it has climbed since the 1950's, all right. However, what units
of
measurement were they using which were noted as ppm(v)? I have never
heard
of this unit of measurement. ppm is usually parts per million parts
of
weight. But the "v" would indicate to me that it may be volume, in
which
case one set of studies is giving parts per million in volume, the
other
in
weight.
(http://cdiac.esd.ornl.gov/trends/co2/graphics/vostok.co2.gif)

On that .GIF, the y-axis is CO2 Condentration (ppmv)

At http://cdiac.ornl.gov/ftp/trends/co2/sposio.co2 ,
one of the links I gave you for CO2 at the South Pole, it says that
the measurements are in ppmv viz.
*** Atmospheric CO2 concentrations (ppmv) derived from flask ***
*** and in situ air samples collected at the South Pole ***

There is no point in you denying the facts. Since the Industrial
Revolution atmospheric CO2 has increased from 280 ppmv to 380 ppmv.

In any event, there is no doubt that the conc. of CO2 is increasing,
but
look at the long picture, it has done this four times in the past and
man
was not around. Each time it returned to a low range after a period
of
time
(50,000 years). The earth's time is different from man's time. On
the
earth clock, a billion years is but an hour.

The four times in the past to which you refer, were when the Earth
was warming due to it exiting a glacial period. We are no longer
in a glacial period, hence the reason for the CO2 increasing can
not be due to that. From a geological point of view 380 ppm of CO2
is not exceptional, but from the POV of mankind it certainly is.
I am sure that Earth will laugh of such a small change, but it may
also laugh mankind off its face. Don't forget we have evolved to
survive a range of 180 to 280 ppm. What the effects of 380 ppm are
unknown.

I would say we do not want to put any more co2 into the atmosphere
than
we
have to, but it is not the most important thing that we face, by any
stretch
of the imagination.

How do you know that it is not important. It seems that the increase
in
CO2
is melting the Greenland ice ***, and that will lead to sea levels
rising
by over 20 feet, flooding every port in the world, many of which like
New
York and London are major cities. We are not talking about losing the
Twin
Towers. We are talking about losing every skyscraper in New York!

I've just had a snap look for sources showing the overall ice-budget of
Greenland and Antarctic without finding it. The current melting is a
coastal
phenomena leaving the inner reaches still building up snow-cover.
See ie..W.S.B. Paterson, "The physics of glaciers" 3. ed. 1994
Some altimetry-measurements by flight or satelite should have been
conducted
since.

Here is a link to the more recently published work.
http://www.eurekalert.org/pub_releases/2005-11/esa-eas110405.php

It implies that there is no need to panic because the central ice
cap will grow until the temperature is 3C higher.

However, even more recent than that (also published in Science) is
described here;
New Study in Science Warns of Greenland's Accelerating Glaciers
http://www.aaas.org/news/releases/2006/0216ice.shtml

What Jim Hansen is saying (see my previous post) is that the models
are too simple. What I am saying is that the melting around the
margins of the Greenland ice *** is already accelerating, therefore
we have already reached the tipping point. Unless we reduce the
CO2 levels or do something else to cool the planet, then the melting
of the Greenland ice will speed up and it will soon become a total
loss.

Thank you for the articles. If anything has made me move my opinion on
global changes, it's another branch of environmental science: The population
of East-Greenland are the ones that suffers most (has acumulated the highest
amounts) from the spread of PCB and the rest of "The dirty dozen". It's
staggering how the stuff concentrates in the most unlikely places.
http://www.mst.dk/udgiv/publications/2001/87-7944-977-8/html/kap09_eng.htm

You know my take as a geologist on global climate changes - it happens
through time. I cann't help smiling by the thought of raising my voice
toward US, China and who know where and how meny billions of educated or
uneducated people ... the wheels are rolling and we just love it.
As a measure of precaution we should be careful, sure ... ;o)

I've had a couple of takes on converting some to switch a belief in a 6000
year old to a 4.5 bill y old earth - - - as if it wasn't reasonably clear
compared to climate evolution - - it doesn't encourage me to anything,
except perhaps to invest in rubber-boots.
In my neighbourhood it's sort of partly been taken care of due to
pricing-politics - for a long time there's been a lot of money to be made by
reducing consumption of energy.

Carsten





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