On 08/17/2010 10:15 AM, Rob Dekker wrote:
"Xan wrote in message
...
On 8/14/2010 3:10 AM, Benj wrote:
On Aug 13, 9:48 pm, Xan wrote:
On 8/13/2010 4:44 PM, tunderbar wrote:

I don't agree with how Mann et al. presented their data, and I think
they got off too easily. But none of that has anything to do with the
misleadingly incomplete nature of your statement, "No one is disputing
that the world has gotten warmer since the last glaciation period."

Is it warmer than it was 15,000 years ago? Yes.

What did temperatures do from 11,000 years ago until the mid-20th
Century? They declined slightly.

Here are the Vostok data:

ftp://ftp.ncdc.noaa.gov/pub/data/pal...ca/vostok/deut...

There are ~320 records in that dataset between 15,000 and 150 years ago.
You've got:

- one anecdote about glaciers in SD and NYC 15K years ago, and an
observation that glaciers don't exist in those places any longer,

- an unsupported assertion that ice core data "aren't very valid",

- and finally, one red herring of an opinion that Mann's tree ring
proxies are fraudulent.

You seem like you are smart enough to really fake some data! And you
are doing a pretty good fraudulent job of it too. But you aren't the
smartest one here.

Let's take a close look at your so-called "science".

1. you claim temperatures declined slightly from 11,000 years ago
until mid 20th century.

2. You base this wild claim on ice core data taken at Antarctica at
one location and extrapolate it to the rest of the planet.

My current understanding of glaciation cycles, the topic at hand, is that
they track very closely to regular and predictable changes in insolation
at 65 N and S latitudes according to Milankovitch theory. The implication
here being that glaciation cycles are driven by changes in temperature in
polar and peripolar latitudes. As such, it is entirely appropriate to
*focus* the discussion on a polar temperature proxy that goes far enough
back to reconstruct several glaciation cycles. Vostock is such a proxy --
it contains data for the past 413,000 years.

3. you pooh-pooh the end of the ice age,

Look again at the data, even better make a chart in Excel as I have done.
Compare the shape of the curve in this most recent interglacial to the
three prior 100,000 temperature peaks. Is it unreasonable to
*hypothesize* that a further rise in temperature in the Antarctic is
unlikely to be explained by Milankovitch theory? Explain your
conclusions, and include references to empirical data or published theory.

while agreeing that much data
has already been fraudulently presented as you are doing.

I'll repeat: what do Mann et al., a group of *dendroclmatologists*, have
to do with ice core data?

4. and you ignore the fact that the so-called temperature rise started
back 170 years ago long before oil use was anywhere near today.

Oh dear. I'm talking about an 11,000 year trend, and you're fixated on
one data point in a quite noisy data set.

Age Anomaly ( C )
129 -
149 (0.81)
170 0.02
190 0.36
211 (0.95)
234 (1.84)
258 (1.09)
281 (0.75)
304 (0.22)
327 (0.48)
351 (0.75)
375 0.23
397 1.33
420 0.35
444 0.18
469 (0.08)
495 (1.08)
523 (1.39)
552 (1.61)
581 (0.90)
609 (0.60)
637 (0.02)
665 (0.18)
695 (1.23)
726 (1.54)
757 (0.85)
788 (0.10)
817 (0.17)
848 (0.78)
881 (0.78)
912 (0.17)
944 (0.25)
976 (0.28)
1,009 (0.81)

In a previous post on this thread, I noted that a movement of 1.2C either
side of -0.38C (the mean for the data set between 11,000 and 129 years)
would represent a 95% confidence interval. IOW, most of those
fluctuations in the data aren't significant at that level of confidence.
(Caveat: very back of the napkin calcs here, feel free to do your own
analysis.)

In fact it started at nearly zero.

This isn't science. It's pure propaganda. Let's do science. Climate
isn't weather. Climate isn't even weather at one place in the frozen
south. And that's even if you believe the deuterium theory. Climate is
an average of weather. Well, what would show an average of temperature
over the WHOLE planet and not just Antarctica?

The current network of temperature stations, satellites, buoys is indeed
far more comprehensive. But we didn't have those 11,000 years ago, did
we.

Well at the end of the
ice age I'd say that melting ice pretty much is an indicator of global
temperature. And the level of the sea is a pretty good indicator of
how much ice is melting.

True, but 11,000 years ago we don't have a high resolution, instrumented
record of those parameters.

(Please let us all pause and remember that
all the warming alarmists are claiming that soon all retirees in
Florida will have to move because it'll be under water). Here. Take a
look:

http://www.globalwarmingart.com/wiki..._Sea_Level_png

Gosh, just look at that post-glacial temperature rise! How can that
be when temperatures are really going DOWN in that period?

From 11,000 years ago until 129 years ago, the mean temperature anomaly
decreased -0.1C. I already explained that it was slight.

The link above has this to say:

"This figure shows sea level rise since the end of the last glacial
episode based on data from Fleming et al. 1998, Fleming 2000,& Milne et
al. 2005. These papers collected data from various reports and adjusted
them for subsequent vertical geologic motions, primarily those associated
with post-glacial continental and hydroisostatic rebound. The first refers
to deformations caused by the weight of continental ice sheets pressing
down on the land, the latter refers to uplift in coastal areas resulting
from the increased weight of water associated with rising sea levels. It
should be noted that because of the latter effect and associated uplift,
many islands, especially in the Pacific, exhibited higher local sea levels
in the mid Holocene than they do today. Uncertainty about the magnitude
of these corrections is the dominant uncertainty in many measurements of
sea level change."

Bearing in mind that this only takes into account ice area:

http://nsidc.org/seaice/characteristics/difference.html

Note the very last line of the very last table:

quote
Trend, 1979-2008
Arctic: Significant decrease of 4.1% (~500,000 km2; 193,000 mi2) per
decade
Antarctic: Small increase of 0.9% (~100,000 km2; 42,000 mi2) per decade
/quote

Establishing a relationship between ice area and global temperature is
tough enough, but the key think to think about here is that the Antarctic
gained ice area over a period of time that the Arctic wasn't. I can't make
any conclusions from this, but it *is* interesting, isn't it?

And is there an acceleration post industrial age? No.

You wouldn't be able to see it in that graph due to the scale.

In short you are waving your hands and trying to dazzle them with
jargon hoping there is no one here smart enough to catch you at this
game. But you ARE caught. So just give up and tell everyone that they
must accept that their energy bills will soon be doubled to support
the Third World and they just need to get over it!

If energy bills double over the period of time being talked about in
Kyoto, I'd want to factor in the supply/demand curve of oil over that
period of time. IIRC, projections are that cap and trade would add about
3% to energy costs. Who knows how accurate that number is, but I've never
heard any government proposing 100% energy price increases to meet Kyoto.
Perhaps you have a source for this claim?

And I'm sure some of that money will be coming to you and Algore (he's
obviously already carved a huge slice for himself) for "services".

So what we have here is a PERFECT example of the fraudulent "science"
that is trying to be passed off as some kind of "proof" of your
alarmist prognostications.

What we have is you putting words in my mouth and assuming bad faith on my
part that for reasons that can be explained by my own ignorance, honest
mistakes and/or uncertainty due to the quality and quantity of data I've
presented.

But of course, you're conveniently ignoring my main point to the OP: he
hasn't remotely supported his arguments with any kind of empirical data at
all. Like you, he seems content to spout a bunch of politically motivated
invective supported by a sparing amount of anecdotal evidence, and
liberally peppered with a slew of fallacious rhetorical techniques and
dodges.

I'm betting you were probably part of that
email exchange trying to find ways to fool the public by fudging
data.

LOL. Very scientific.

Point is you are a shame to science and what you are doing here is
WORSE than mouse-painting. At least the mouse-painters were faking
data for personal gain and weren't trying to plunder the world with
their fraud.

You have NO room to accuse anyone of "poor science".

Uh, ok. I hope you feel better having gotten all that off your chest.

-Xan

Xan,

Thank you for your excellent explanations and clear thinking.

Related to your statements about the Milankovitch cycles, and the importance
of insolation at 65 N, I have a question :

Do you know which reasons as an explanation for why 65 N insolation in the
Milankovitch cycles seem to dictate the onset and demise of ice ages ?
Why not 65 S ? Or even better : Why is the Vostok ice core temperature data
(in the Southern Hemisphere) a slave to insolation at 65 N (in the Northern
Hemisphere) ?
And even more interesting, the changes in solar irradiance numbers for 65 N
in the Milankovitch cycle (some 50 W/m^2 difference), seem to be consistent
with the swings in temperature for the planet as a whole (including
Antarctica), when we fill in such numbers into the Stephan Bolzmann equation
(10 C difference).
I wonder if that is a coincidence, and why the irradiance in the Southern
Hemisphere does not seem to matter much when it comes to determining the
overall planet's surface temperature...

Rob



Rob,
I thought at first that the answer was very simple - there is no land
mass of any significance at 65° South. However, on reflection it seems
less straightforward than that.
The Milankovitch cycles do not change the total irradiance averaged
over the year and the globe significantly, but rather change the
distribution of seasonal intensity. That means that if the NH
insolation decreases, the SH insolation increases by the same amount.
Ocean water is an almost perfect absorber of sunlight,
so even though an ice cap might be forming in the NH as a result of the
reduced summer insolation, the oceans in the SH should be getting
warmer. Nevertheless, from the point of view of the energy balance, the
change in total albedo as a result of the ice formation once underway is
such that total global insolation decreases.

As to the question why glaciation does not occur on the opposite phase
of the Milankovitch cycle - possibly the massive ice sheets cannot form
on ocean water? It would seem that the formation of a permanent ice
sheet needs solid land, maybe mountains, to nucleate.
There's a climate model he
http://geosci.uchicago.edu/~archer/r...05.trigger.pdf
with some references.

T.
(x-post alt.conspiracy removed)

Martin and Xan, thanks for your reply (similar to Tom's) also !
Let me just reply here (partly because Tom rightfully removed alt.conspiracy; (which I should have done already )).

"Tom P" wrote in message ...
On 08/17/2010 10:15 AM, Rob Dekker wrote:
"Xan wrote in message
...
.............

Xan,

Thank you for your excellent explanations and clear thinking.

Related to your statements about the Milankovitch cycles, and the importance
of insolation at 65 N, I have a question :

Do you know which reasons as an explanation for why 65 N insolation in the
Milankovitch cycles seem to dictate the onset and demise of ice ages ?
Why not 65 S ? Or even better : Why is the Vostok ice core temperature data
(in the Southern Hemisphere) a slave to insolation at 65 N (in the Northern
Hemisphere) ?
And even more interesting, the changes in solar irradiance numbers for 65 N
in the Milankovitch cycle (some 50 W/m^2 difference), seem to be consistent
with the swings in temperature for the planet as a whole (including
Antarctica), when we fill in such numbers into the Stephan Bolzmann equation
(10 C difference).
I wonder if that is a coincidence, and why the irradiance in the Southern
Hemisphere does not seem to matter much when it comes to determining the
overall planet's surface temperature...

Rob



Rob,
I thought at first that the answer was very simple - there is no land mass of any significance at 65° South. However, on
reflection it seems less straightforward than that.
The Milankovitch cycles do not change the total irradiance averaged over the year and the globe significantly, but rather change
the distribution of seasonal intensity. That means that if the NH insolation decreases, the SH insolation increases by the same
amount.
Ocean water is an almost perfect absorber of sunlight,
so even though an ice cap might be forming in the NH as a result of the reduced summer insolation, the oceans in the SH should be
getting warmer. Nevertheless, from the point of view of the energy balance, the change in total albedo as a result of the ice
formation once underway is such that total global insolation decreases.

Thank you for wording it much better than I did.
I fully agree that if insolation in the NH is low, and high in the SH, that the ice and snow on NH landmasses would increase Earth's
albedo and thus would result in an average lower temperature for the planet as a whole.

However, that does not take away the fact that the SH should be warmer than it would be when the tables were turned (low insolation
in SH and high in NH).

So the issue remains as to why the Vostok Ice Cores (most certainly in the SH ) still shows lower temperatures when the
Milankovitch cycles indicate high SH irradiance, and higher temperatures when the SH has lower irradiance....

The Vostok ice shows temperatures when the NH is obviously in an ice age. And that cannot be so obviously explained with the
Milankovitch cycle showing high SH irradiance.

That's what I meant when I wrote that the SH seems to be a slave of the NH irradiance.
I doubt that Vostok's precipitation (and with that it's 'deuterium' fraction) came straight from the NH.
So I must be misunderstanding something basic about these Milankovitch cycles and the irradiance in NH and SH that it modulates, or
about the planet's response to these modulations.


As to the question why glaciation does not occur on the opposite phase of the Milankovitch cycle - possibly the massive ice sheets
cannot form on ocean water? It would seem that the formation of a permanent ice sheet needs solid land, maybe mountains, to
nucleate.
There's a climate model he http://geosci.uchicago.edu/~archer/r...05.trigger.pdf with some references.


That I think is plausible, and is consistent with your suggestion above that Earth's albedo (due to snow and ice) is more sensitive
to irradiance changes in the NH.

T.
(x-post alt.conspiracy removed)

On 18/08/2010 08:21, Rob Dekker wrote:
Martin and Xan, thanks for your reply (similar to Tom's) also !
Let me just reply here (partly because Tom rightfully removed alt.conspiracy; (which I should have done already )).

"Tom wrote in message ...
On 08/17/2010 10:15 AM, Rob Dekker wrote:
"Xan wrote in message
...
............

Xan,

Thank you for your excellent explanations and clear thinking.

Related to your statements about the Milankovitch cycles, and the importance
of insolation at 65 N, I have a question :

Do you know which reasons as an explanation for why 65 N insolation in the
Milankovitch cycles seem to dictate the onset and demise of ice ages ?
Why not 65 S ? Or even better : Why is the Vostok ice core temperature data
(in the Southern Hemisphere) a slave to insolation at 65 N (in the Northern
Hemisphere) ?

Rob,
I thought at first that the answer was very simple - there is no land mass of any significance at 65° South. However, on
reflection it seems less straightforward than that.
The Milankovitch cycles do not change the total irradiance averaged over the year and the globe significantly, but rather change
the distribution of seasonal intensity. That means that if the NH insolation decreases, the SH insolation increases by the same
amount.
Ocean water is an almost perfect absorber of sunlight,
so even though an ice cap might be forming in the NH as a result of the reduced summer insolation, the oceans in the SH should be
getting warmer. Nevertheless, from the point of view of the energy balance, the change in total albedo as a result of the ice
formation once underway is such that total global insolation decreases.

Thank you for wording it much better than I did.
I fully agree that if insolation in the NH is low, and high in the SH, that the ice and snow on NH landmasses would increase Earth's
albedo and thus would result in an average lower temperature for the planet as a whole.

However, that does not take away the fact that the SH should be warmer than it would be when the tables were turned (low insolation
in SH and high in NH).

Although a lot of that warmth is landing on relatively mobile oceans and
being shunted around by currents.

So the issue remains as to why the Vostok Ice Cores (most certainly in the SH ) still shows lower temperatures when the
Milankovitch cycles indicate high SH irradiance, and higher temperatures when the SH has lower irradiance....

The Vostok ice shows temperatures when the NH is obviously in an ice age. And that cannot be so obviously explained with the
Milankovitch cycle showing high SH irradiance.

When water is locked up in an ice sheet it can no longer return to the
seas. Light isotopes of water preferentially evaporate because there is
some mass fractionation. The longer the period of glaciation and the
more ice and snow locked up the isotope ratio of the remaining liquid
water becomes more biassed in favour of heavy water isotopes.

SIRA of water ice is a good proxy for *global* average temperature as a
result. Strictly it is a direct measure of the total volume of water
remaining in circulation as liquid and vapour phase at any given time.

That's what I meant when I wrote that the SH seems to be a slave of the NH irradiance.
I doubt that Vostok's precipitation (and with that it's 'deuterium' fraction) came straight from the NH.
So I must be misunderstanding something basic about these Milankovitch cycles and the irradiance in NH and SH that it modulates, or
about the planet's response to these modulations.

The precipitation contains light biassed isotopes of water. In normal
conditions this mostly runs back down the rivers and returns to the sea,
but when they are locked into permanent ice sheets the oceanic isotope
ratio changes and as a consequence so does the isotope ratio in new
precipitation. Ice cores allow this information to be read back.


As to the question why glaciation does not occur on the opposite phase of the Milankovitch cycle - possibly the massive ice sheets
cannot form on ocean water? It would seem that the formation of a permanent ice sheet needs solid land, maybe mountains, to
nucleate.
There's a climate model he http://geosci.uchicago.edu/~archer/r...05.trigger.pdf with some references.

That I think is plausible, and is consistent with your suggestion above that Earth's albedo (due to snow and ice) is more sensitive
to irradiance changes in the NH.

It would be more accurate to say that for a given average global
temperature a cold N hemisphere and warm S will accumulate much larger
permanent ice sheets than vice-versa. So a cold N hemisphere will be
reflected in a bigger shift in water SIRA even before the higher albedo
feedback kicks in.

The global average temperature could for arguments sake be the same but
unless there was a very large area of permanent sea ice glacier formed
in the southern hemisphere there is only Antarctica to dump snow on.

Regards,
Martin Brown

"Martin Brown" wrote in message
...
On 18/08/2010 08:21, Rob Dekker wrote:
Martin and Xan, thanks for your reply (similar to Tom's) also !
Let me just reply here (partly because Tom rightfully removed
alt.conspiracy; (which I should have done already )).

"Tom wrote in message
...
On 08/17/2010 10:15 AM, Rob Dekker wrote:
"Xan wrote in message
...
............

Xan,

Thank you for your excellent explanations and clear thinking.

Related to your statements about the Milankovitch cycles, and the
importance
of insolation at 65 N, I have a question :

Do you know which reasons as an explanation for why 65 N insolation in
the
Milankovitch cycles seem to dictate the onset and demise of ice ages ?
Why not 65 S ? Or even better : Why is the Vostok ice core temperature
data
(in the Southern Hemisphere) a slave to insolation at 65 N (in the
Northern
Hemisphere) ?

Rob,
I thought at first that the answer was very simple - there is no land
mass of any significance at 65° South. However, on
reflection it seems less straightforward than that.
The Milankovitch cycles do not change the total irradiance averaged
over the year and the globe significantly, but rather change
the distribution of seasonal intensity. That means that if the NH
insolation decreases, the SH insolation increases by the same
amount.
Ocean water is an almost perfect absorber of sunlight,
so even though an ice cap might be forming in the NH as a result of the
reduced summer insolation, the oceans in the SH should be
getting warmer. Nevertheless, from the point of view of the energy
balance, the change in total albedo as a result of the ice
formation once underway is such that total global insolation decreases.

Thank you for wording it much better than I did.
I fully agree that if insolation in the NH is low, and high in the SH,
that the ice and snow on NH landmasses would increase Earth's
albedo and thus would result in an average lower temperature for the
planet as a whole.

However, that does not take away the fact that the SH should be warmer
than it would be when the tables were turned (low insolation
in SH and high in NH).

Although a lot of that warmth is landing on relatively mobile oceans and
being shunted around by currents.

Thank you. That makes sense.
But remember that the difference in irrandiance between the NH and SH in
extreme Milankovitch cycle points would be more that 100 W/m^2 (please
correct me if I'm wrong with this).
If oceanic heat transport would be responsible for cooling the opposite
hemisphere to the point where the 'warm' hemisphere would cool down to the
level of the 'cold' hemisphere, then oceanic heat transport would have to be
in the range of some 6300 TW (if I did my calculations correctly).
Do you think that oceanic heat transport can realistically be of that
magnitude ?



So the issue remains as to why the Vostok Ice Cores (most certainly in
the SH ) still shows lower temperatures when the
Milankovitch cycles indicate high SH irradiance, and higher temperatures
when the SH has lower irradiance....

The Vostok ice shows temperatures when the NH is obviously in an ice age.
And that cannot be so obviously explained with the
Milankovitch cycle showing high SH irradiance.

When water is locked up in an ice sheet it can no longer return to the
seas. Light isotopes of water preferentially evaporate because there is
some mass fractionation. The longer the period of glaciation and the more
ice and snow locked up the isotope ratio of the remaining liquid water
becomes more biassed in favour of heavy water isotopes.

SIRA of water ice is a good proxy for *global* average temperature as a
result. Strictly it is a direct measure of the total volume of water
remaining in circulation as liquid and vapour phase at any given time.


I am not sure if I understand you right here.
Are you saying that the amount of water on the planet locked up in ice and
snow (during an ice age) could be such a significant fraction of the total
amount of water present on the planet that it would alter the concentration
of deuterium in the oceans ?

That's what I meant when I wrote that the SH seems to be a slave of the
NH irradiance.
I doubt that Vostok's precipitation (and with that it's 'deuterium'
fraction) came straight from the NH.
So I must be misunderstanding something basic about these Milankovitch
cycles and the irradiance in NH and SH that it modulates, or
about the planet's response to these modulations.

The precipitation contains light biassed isotopes of water. In normal
conditions this mostly runs back down the rivers and returns to the sea,
but when they are locked into permanent ice sheets the oceanic isotope
ratio changes and as a consequence so does the isotope ratio in new
precipitation. Ice cores allow this information to be read back.


I agree that the light biassed isotopes of water tend to be prevalent in
precipitation, and even better, that the amount of this is an indication of
the temperature of the water vapor that formed the precipitation in the
first place. After all, this is why the deuterium isotope ration is an
indication of the temperature in the region at the time the precipitation
fell.
But I do not see the significance of your statement regarding the "new
precipitation".
Can you elaborate on that ?


As to the question why glaciation does not occur on the opposite phase
of the Milankovitch cycle - possibly the massive ice sheets
cannot form on ocean water? It would seem that the formation of a
permanent ice sheet needs solid land, maybe mountains, to
nucleate.
There's a climate model he
http://geosci.uchicago.edu/~archer/r...05.trigger.pdf with
some references.

That I think is plausible, and is consistent with your suggestion above
that Earth's albedo (due to snow and ice) is more sensitive
to irradiance changes in the NH.

It would be more accurate to say that for a given average global
temperature a cold N hemisphere and warm S will accumulate much larger
permanent ice sheets than vice-versa. So a cold N hemisphere will be
reflected in a bigger shift in water SIRA even before the higher albedo
feedback kicks in.

The global average temperature could for arguments sake be the same but
unless there was a very large area of permanent sea ice glacier formed in
the southern hemisphere there is only Antarctica to dump snow on.

That's true.
The area in the SH is limited.
One may argue that if the NH is in an ice age, that so much water gets
locked up that the ocean levels would drop significantly, and thus it would
create more dry land in the Southern Hemisphere. I'm not sure how much more
land that effect would create, but it may be a factor to consider.

Other than that, the altitude of the Antarctica ice sheet would surely be
variable.
I wonder how high the ice could have gotten during high-irradiance and
low-irradiance phases of the Milankovitch cycles.


Regards,
Martin Brown