Re: OT - Hansen acknowledges solar forcing


Raveninghorde wrote:
On Thu, 29 Jan 2009 09:34:40 -0800 (PST), bill.sloman@xxxxxxxx wrote:

I thought you would benefit from an overview I put together for my
younger daughter. Her school are opposing Kyoto in a UK youth
parliament debate. I've already posted many of the links for you in
previous posts.

Has CO2 increased or is this just natural variation?

Summary:

http://www.biokurs.de/treibhaus/180CO2/bayreuth/bayreuth1e.htm

detail:

http://www.biomind.de/nogreenhouse/daten/EE%2018-2_Beck.pdf

Which severely over-values the pre-1900 chemical measurements, so the
authors ended up having to publish it in "Energy and Environment"
where
the peer-review process is skipped for papers that fit the denialist
agenda.

How reliable are current measurements:

CO2 has been measured at Mauna Loa Observatory Hawaii since 1959.
Mauna Loa is the world's largest active volcano and emits CO2.

http://www.mlo.noaa.gov/programs/esrl/volcanicco2/volcanicco2.html

/quote

A volcanic component can be estimated by taking the difference in
concentration between periods when the plume is present and periods
immediately before and after that exhibit baseline conditions.

Right after the 1984 eruption, Mauna Loa emitted as much CO2 as an
American city of 40,000 people. By 2005, these emissions had fallen by
a factor of about 100.

/end quote

The Mauna Loa CO2 observatory happens to be in a position to notice
when the volcano is active, and edits out the occasional contaminated
observation. They are rare.

The data before 1959 is taken from Law Dome ice core samples.

http://cdiac.ornl.gov/trends/co2/lawdome.html

Note that the air is actually 40 to 80 years younger than the ice it
is trapped in. Or is it? Has the information been massaged to give the
right answer?


Unlikely. The ice orginally fell as snow, which has a fairly open
structure.
You don't get totally enclosed air bubbles until quite a lot of snow
that
has fallen on top of it. Forty to eighty years sounds like a lot of
snow,
but the Vostok ice cores are of the order of a kilometre in lenght
and
cover several hundre thousand years. so each annual snow layer ends
up only a couple of millimetres thick, compressed from an intial
thickness
of some 500mm.

Diffusion in the gasphase is much faster than it is through condensed
matter, so it isn't surprising that buried gas bubbles are
appreciably
younger than the snow layer that surrounds them.

/quote

The enclosed air at any depth in the ice has a mean age, (aa), that is
younger than the age of the host ice layer (ai), from which the air is
extracted.

/end quote

As usual, you are getting excited about well-known and well-understood
phenomena, and making fatuous claims about their significance.

I've snipped the rest of your recycled misapprehensions. You've posted
it all before.

--
Bill Sloman, Nijmegen
.

Relevant Pages

  • Re: Something wrong with the ice cores?
    ... Ice core samples show a nice steady line like they have been smoothed. ... around in high winds giving the impression of snow fall. ... If you wanted a device to rid the ice of CO2 ... The fact that the top layers of snow get blown about isn't a problem, because the CO2 doesn't come from the snow itself, but from the air as it gets captured deep in the snow layer. ...
    (uk.sci.astronomy)
  • Re: Phoenix Lands on Mars this Sunday!!!
    ... I don't think it's going to get buried under ice; ... to get covered in CO2 hoarfrost and maybe a little water snow. ... snow, not freeze it inside a block of ice like you seem to indicate. ... Given the long period of the Martian year, ...
    (sci.space.history)
  • Re: Comet impact theory disproved
    ... Nanodiamonds are found in sediments of many ages; ... the last advance of the Cordilleran Ice Sheet into Alberta, ... The researchers gave it a Younger Dryas age based on ... but rather fine sediment that had been deposited on top of it. ...
    (sci.archaeology)
  • Re: Comet impact theory disproved
    ... Nanodiamonds are found in sediments of many ages; ... the last advance of the Cordilleran Ice Sheet into Alberta, ... The researchers gave it a Younger Dryas age based on ... but rather fine sediment that had been deposited on top of it. ...
    (sci.archaeology)
  • Re: twats on the roads!
    ... On my way to work in the van and going through suburbia to get to the petrol station that does cheap LPG on the way, instead of going around the edge to get directly onto the M4. ... Taking it easy, but it's all fairly main suburban through roads and they all seemed well enough gritted (or just not affected by ice or well used enough) to not be a problem - all 30/40 limits anyway, so not haring about anyway. ... Now even in my younger days I'd have slowed down, but still possibly come a cropper just due to not being experienced enough in terms of knowing quite how much to slow down. ... Good old modern safety features! ...
    (uk.rec.cars.modifications)
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