On 3 Jul 2005 20:51:22 -0700, wrote:



Mark & Juanita wrote:
On 3 Jul 2005 00:41:19 -0700, wrote:



Mark & Juanita wrote:
On 2 Jul 2005 21:57:11 -0700, wrote:


.... snip


... alright fred, present a credible source for how global temperature
change in tenths of a degree (which is the amount and rate being cited for
global warming evidence) can be identified for periods before accurate
weather records were kept.

Why should I? You haven't presented any credible source indicating
that anyone claims to be able to do so.



As you are so fond of saying, Google is your friend.

My first response was snide and I've deleted it.

What cuaght my eye was your statement "The idea that by measuring
tree ring size, one can determine the average temperature of an
area to within tenths of a degree is ludicrous."

A quick google search using the search terms "tree ring" and "average
temperature" does not yield anyoone making such a claim.

So, I remain skeptical that such a claim has been made.


Try to hearken
back to various debates in which the infamous "hockey stick" chart is shown
that attempts to show departures from average temperatures in 1961 to 1990
for the years 1000 AD to current time, showing this sudden jump of +.5C
when the other tempertures were below. The difference is less than 0.5 C.
The "measurements" from tree rings, corrals, ice cores and "historical
records" (remember that no calibrated met stations existed in 1000 AD) are
all being pegged at less than 0.5 C increments.

A Google search for "hockey stick chart" yields a few pages that come
up 404, perhaps due ot the NHL strike, and a few that criticize
"the hocky stick chart" but I haven't found any explanation of the
chart itself.

One example is found he

http://www.greeningearthsociety.org/...4/wca_24c.html

The chart appears to be a graph of temperature as a function
of time. Note the caption on the left side which indicates
the temperature origin is a "1961 to 1990 average." What is
meant by "1961 to 1990 average" is a mystery to me but inasmuch
as choice of origin is arbitrary let's not worry about
that.


You have the correct chart. This is the chart that various ("Earth in
the Balance") former presidential candidates have used to highlight the
future devastation to be caused by the alarming increase in temperature in
only the past several years. The 1961 to 1990 average temperature was
taken as a baseline and is the zero bar of said chart. The numbers below
zero indicate average temperatures below the reference bar and those above
indicate average temperatures greater than the reference. The large spike
at the end of the chart is intended to cause alarm due to a) it's large
slope and b) the fact that it is fully 0.5 C above the average from the
previous 30 years and well above the average for the past millenia.


It looks to me like the error bars (in grey--if those are
not error bars I don't know what they are) are about +/-
.5 degree for observations prior to about 1600, perhaps +/-
.3 degrees from 1600 - 1900 and I won't hazard a guess as
to what they are in the more recent data.


Given that the grey bars are error bars, then the overall exercise and
alarmism raised by the presentation of said chart are beyond simple
hysterics and border on fraud. The blue and red lines are those focused
upon the by the Chicken Little crowd. The error bars indicate that this
entire exercise is attempting to extrapolate future climate from noise.
Having spent the last 15 years of my career in various development projects
that rely heavily upon integration and test and data collection, I can
categorically state that attempting to extrapolate performance from noise
measurements is a fool's errand.


So, what again is your objection? Do you feel the the variance
in the data prior to 1600 was underestimated? If so, what
do you allege has been mishandled in the error estimation?


That the error bars are only 0.5C is the first part that anyone with some
degree of skepticism should focus upon. The second is the deltas that are
being extrapolated for periods before the advent of the thermometer are
being assessed at less than 0.5C, when the exact causes for tree ring size,
ice core sample depth, and other "indicators" are hardly precise enough to
estimate global average temperature to such a degree of precision.



What do you mean by "pegged at less than 0.5 C increments"?

"Pegged" is usually used to mean a hard limit, for example met
sensor data showing relative humidity inexcess of 100% may be
arbitrarily adjusted to ("pegged" at) 100% at ingest, though
the term more often refers to a hard limit on the measurement
device itself (e.g. "pegging the meter").


Oh please, let's not play games with semantics, you know darned well what
I meant, i.e. that the error bars shown are at best 0.5C, the attempt to
show increments of less than 0.1C are simply ludicrous. Substitute
"represented", or "reported" for "pegged" if that makes you feel any
better.


The only 0.5 degree C increments I see are the major tick spacing
on the vertical (temperature) axis. Again, like the choice of
origin, that is arbitrary.

IOW, I don't see anything here to the effect of "that by measuring
tree ring size, one can determine the average temperature of an
area to within tenths of a degree is ludicrous."


Take a closer look a the graph, the numbers for the era before the
thermometer was invented are being estimated based upon tree ring
measurements, ice core samples and historical records (i.e, some current
era literati writing, "dang, it's cold this winter!" or "We had to order 5
more pairs of longjohns this winter"). Now, look at the blue lines, look
at the zero reference line, this graph is trying to tell you that global
average temperature was moving around 0.2 to 0.5C below the global average
reference line.


If it is your intent to make another point, that point is lost
on me.



The point is that this is the kind of evidence that is "widely accepted"
and "peer reviewed" and critically acclaimed as showing the coming
environmental disaster that is global warming. It is also the kind of
evidence to which people are referring when they say, "it has been proven
that global warming is occuring."



.... snip


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If you're gonna be dumb, you better be tough

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