Re: REALITIES OF GLOBAL WARMING

From: Ian St. John (istjohn_at_noemail.ca)
Date: 10/22/04 

Date: Fri, 22 Oct 2004 10:46:33 -0400

Richard wrote:
> Ian St. John wrote:
>>
>> It is not a fact that GLOBAL temperatures were higher 1,000 years
>> ago, for example. This is a distortion that is created out of a
>> regional warming in the Western European area where most of the
>> oldest documents remain so it gives a distorted picture of the
>> world. We know better because of long term wide ranging
>> dendrochronology , borehole and ice core studies.
>>
> Ok, now we're getting to the interesting stuff.

O.K.

> Isn't it that only Mann said that there's *no* Medieval warming period
> based on data collected in the Western US?

Very wrong.

1: There is a Medieval Warming Period and a Little Ice Age. It is, however,
regional in extent.
2: Mann did studies averaging the temperature trends of the entire Northern
Hemisphere, and this showed no spike during the MWP/LIA period, showing that
the MWP/LIA was a regional climate change associated with the movement of
heat from one region to another, NOT the overall temperature.
3: All dendrochronology, borehole and ice core studies are consistent with
this. One clue is that studies which exclude the equatorial regions up to
about 30 degrees show the MWP/LIA around the globe at high latitude with a
concentration in Western Europe where it was noted. This indicates that it
was a change in the heat distribution at high latitudes and probably
concentrated in Western Europe because the Asian continent blocks the
westerly flows.

> And that this was
> challenged by the Soon and Baliunas study that the warming period
> *does* exist?

The Soon/Baliunas so called study did not establish that it did or didn't
exist. As a regional climate change, it is known to exist. What Soon and
Baliunas did was take a few cherry picked points and try to claim that it
was global. Their 'study' was seriously flawed.

> All ofcourse based on proxy-data.
> Also Mann's data does show there hasn't been a "Little Ice Age". Also
> based on proxy data.

No. It shows that there was not a GLOBAL MWP/LIA where the entire WORLD
warmed and cooled. Given the rate at which the MWP/LIA warmed and cooled in
Europe, the amount of energy to make this happen globally is just not to be
believed. Until you can come up with a reasonable mechnaism for such rapid
changes in the energy content of the globe, the issue is dead as a
comparison between global and regional temperature trends. The globe has
warmed by 0.6C in 120 years vs the MWP warming of 5C in a decade or so.
Obviously the greenhouse effect is too weak to explain a *GLOBAL* MWP/LIA so
what happened? They missed the sudden appearance of a nearby supernova? And
the LIA was caused by?

> However I know of a temperature set going back to
> the early 1700s (KNMI: national weather institute here in The
> Netherlands) that does show a significant cooling.

Exactly. And of course that is highly regional and in the Western European
area of the MWP/LIA. Should I be surprised??? Dendrochronology studies of
the Western Europe area clearly show the MWP and LIA. Your confusion is
between REGIONAL and GLOBAL. A trick that the junk science websites tend to
overwork.

> Ok, now you say I'm
> confusing weather with climate.

NO NO. Regional vs Global. \

> But I'm only giving this fact to show
> that Mann's proxy-conclusions show a different picture than actual
> temperature readings done in the 1700s.

No. They don't.

> The Soon and Baliunas study
> does show a "Little Ice Age" in different parts of the world,

No. It doesn't. It shows warming and cooling in different regions without a
connection either in time or space. Nor is there a postulate as to the
mechanism of warming or cooling the entire globe. Regional warmings and
coolings happen all the time and if you cherry pick a few you can establish
anything you like regardless of the facts. Which is what they did allowing
such a wide window of time that you couldn't help but find SOME warming or
cooling in the time frame from local climate processes.

> so it may well be reasonable to assume this was a worldwide phenomenon.

No. To show a global phenomenon, you would need to both show that the
warming and cooling were during the same period, not just overlapping in a
wide five century 'window' the MWP/LIA and you would have to show a
mechanism for adding millions of quads of energy to the globe over a decade
or less and then taking it away. Nobody has come up with anything reasonable
that I know of. The main determinant of the global total energy is the
tropopause where convection gives way to radiation heat transfer ( and thus
radiation to space ). Only three natural processes are known to affect the
thermal balance of the world significantly.

Volcanic eruptions can cast massive amounts of dust into the upper
atmsophere, but global volcanic activity of this magnitude would be recorded
everywhere as the 'end of the world'.

Solar insolation can change ( but this would also be noted and we have proxy
studies on the strength of the solar radiation ( from isotopes created by
cosmic rays which tend to follow the suns activity due to the shielding
effect of the solar magnetism ) and while the sun did decrease in magnitude
by about 0.24% during the 'Maunder Minimum' associated with the onset of the
LIA this does not come anywhere NEAR the amount necessary to explain either
the MWP or the LIA. It may have been a *trigger* event that changed the
regional climate dynamics to switch between the MWP and LIA.

The greenhouse effect can change the depth of atmosphere warmed and thus the
surface temperature,but no large releases of greenhouse gasses have been
postulated. This may be the most feasible mechanism, if you had a large
eruption of distrurbed methane clathrates. The instruments of the day would
not even notice a change in the methane content of the air, but you would
have though that such would be detected in modern analysis of ice core
samples which trap air from the period.

More importantly, *regional* analysis of the MWP in dendrochronology studies
NOT centered in Europe show no MWP or LIA period. Because the northern
hemisophere holds most of the land, and most of the trees, it is the most
robutstly determined area of the world for such studies. The southern
hemisphere has huge areas of ocean that cannot be well characterised. This
is one reason that he Mann, et al studies concentrated on the Northern
Hemisphere data. ftp://holocene.evsc.virginia.edu/pub/mann/littleiceage.pdf
see Central England in Table 2 and compare with other regions. You can see
the distinct MWP/LIA trends in central england quite easily but ONLY there.

Note also that climate is though not to be able to cross the equator due to
the nature of the circulation cells and thus the NH and SH are separate in
their climate response. What could affect both hermispheres at the same
time? Only insolation, aerosols and the GHE as noted above and what could
drive any one of these mechanisms to a rate of warming ten to a hundred
times greater than the current? And without the driving mechanism being
dramatic enough to be noticed????? You just don't change planetary
equilibrium on that kind of scale at that kind of rate without a major
event.

> The
> same study also shows an equal picture for the "Medieval warming
> period".

The Soon and Baliunas study was a shitstorm, and does not show anything very
well. They are working outside of their area of expertise and are clearly
working on an predetermined agenda. Not a source of good science. They may
have some points about sensitivity to selection of data, but that is still
being argued. The principle component analysis is used by several other
scientists in the same field with similar results but with a different
selection of data which argues that the Mann, et al technique is robust.
Maybe too robust.. There is a recent paper out that claims it may
underestimate short term variability but the MWP and LIA were NOT short term
variations, so they should have showed even under the critique of their
methods as suppressing short term peaks and valleys.

>
> Now I'm really confused. Why should Mann's conclusions be accepted
> without a doubt

They aren't. They are just competent science done by an expert in that
field. Even the IPCC did theri own variations on his techniques to get their
own results and found them consistent overall with the Mann, et all 1999
paper.

> and do we have to disregard Soon and Baliunas's???

Rather than disregard them, you should critique their paper to see if they
have 'hit' on something. The climate scintists don't disregard them. I don't
even require you to come up with a mechanism for warming and cooling the
world. First the data, then the explanation. But first you must have SOLID
reasons for believing that the MWP/LIA was global in extent as well as
synchronous in time, and THEN you have the even more massive problem of
explaining this sort of weirdness in terms of where did the energy come from
and go to? Also, note that scientists showing a lack of impartiality such
as Soon, Baliuna, Michaels, etc should have to pass a harder review than
those who are just letting the cards fall as they may.

http://www.msc-smc.ec.gc.ca/education/scienceofclimatechange/publications/developments/climate_trends-03_e.html
Soon,W. and Baliunas,S. 2003. Proxy climatic and environmental changes of
the past 1000 years. Climate Research 23:89-110.
In this paper, American astrophysicists Soon and Baliunas undertake a
comprehensive review of some 240 studies, published over the past 40 years,
that provide local and larger scale temperature and precipitation proxies
based on paleo data. They conclude that these studies show evidence of a
widespread Little Ice Age (LIA) anomaly (defined as of 50 year duration)
between 1300 and 1900, and a Medieval Warm Period (MWP) anomaly between 800
and 1300. Furthermore, for many locations, the MWP had a warmer 50 year peak
anomaly than that observed in the 20th century. They also find fault with
some of the methodologies used by Mann et al. in developing an aggregate
Northern Hemisphere proxy temperature record. Soon and Baliunas argue that
their findings undermine the conclusion of Mann et al. (and accepted by the
IPCC TAR) that the 20th century warm period was likely unprecedented within
the past 1000 years and therefore unusual. The study is a reminder that the
debate about whether or not the warming over the past 50 years could be
entirely due to natural causes is not over. However, in many respects, the
authors present conclusions similar to that of the IPCC, with one major
exception. That is that, while most areas of the Northern Hemisphere
experienced a warm period at some time during the 800 to 1300 MWP window,
the timing of the anomaly varied from location to location, so that there
was no single synchronous warm period over the Northern Hemisphere. When
spatially averaged, there was no clear evidence of a Northern Hemisphere
MWP.

Soon, W.W.-H., D.R. Legates, and S.L. Baliunas, 2004. Estimation and
representation of long-term (>40 year) trends of Northern-Hemisphere-gridded
surface temperatures: A note of caution. Geophys. Res. Letters., 31,
doi:10.1029/2003GL019141.
Three American scientists examine the methods recently used by some
paleoclimatologists to calculate smoothing trends for recent instrumental
temperature data. Past studies reported in the IPCC TAR and more recently by
Mann and Jones (2003) use a 40-year smoothing trend for both millennial
scale trend analysis and, for comparison purposes, for the instrumental
record of the past 150 years. For the last 20 years of the record, those
studies use a statistical technique for extending the trends to the end of
the record by using mean values to extrapolate up to 20 years into the
future. Soon et al. apply their own methods for calculating this extended
smoothed trend line to the end of the century. The results illustrate the
sensitivity of the trend calculations to the method used and the importance
of describing methodologies used in reporting data trends. However, they
also significantly overstate the problem by incorrectly claiming that some
of the published studies use the smoothing analyses to claim warming rates
between 2002 and 2003 of 1 to 2.5C/decade!

>
> Richard

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