Re: [asa] What's so hot about fickle science?

From: PvM <>
Date: Sun Feb 04 2007 - 15:09:04 EST

Given the fact that the text used the term 'fraudulent data' and
claimed that the hockey stick data were wrong, it may be helpful for
those interested in the 'controversy' to understand the history of the
hockey stick data, some of the common and fallacious objections to the
hockey stick data and the present state of the hockey stick data.

One does not have to search long to find a good overview of the issue

The Hockey Stick

What better resource than to quote the article which accuses of faking
the data (incorrect accusation btw)

<quote>The Hockey Stick Graph

The so—called "hockey stick" graph appears in the 2001 report of the
Intergovernmental Panel on Climate Change (IPCC), the United Nations
organization that dominates climate change discussion. The graph
purported to show that world temperatures had remained stable for
almost a thousand years, but took a sudden turn upward in the last
century (the blade of the hockey stick). It was the product of
research into "proxy" temperature records, such as tree rings, ice
cores, and coral reefs, by Michael Mann, the Joe Wilson of climate
change. It can be seen here. Charles Martin took a critical look at
it last March for The American Thinker.

The problem is that the world was almost certainly warmer than it is
today during the "Medieval Warm Period" or "Medieval Climate Optimum"
of the 9th through 14th Centuries, which was followed by the "Little
Ice Age" of the 15th through 19th Centuries, whose end is the occasion
for today's global warming hysteria.

But Science magazine stuck to its argument. "Politicians Attack, But
Evidence for Global Warming Doesn't Wilt" in the July 28 issue of
Science not only employs the typical deceitful rhetoric of the
scientific establishment, here presenting an argument among scientists
as an argument between scientists and politicians, but also uses the
fake—but—accurate excuse for the corrupt activities of its favorite

Mann's statistical methodology was soon exposed as flawed, if not
downright fraudulent, by Stephen McIntyre and Ross McKitrick, and he
responded by refusing to make public the details of his analysis. This
in turn angered Joe Barton and other members of the Subcommittee on
Oversight and Investigations of the House Energy and Commerce
Committee, who objected to this arrogant refusal to allow oversight of
federally financed research—either by the responsible congressional
committees or by the scientific community.</quote>

So here we have set the stage, the 2001 work by Mann, as reported in
the IPCC report was fraudulent, fake and you name it. And yet, despite
these strongly worded accusations, reality quickly shows that they are
and remain unfounded

Some examples that now should cause much embarassment

("As to Mann's scandalous statistical manipulations" , "Mann's
statistical methodology was soon exposed as flawed, if not downright
fraudulent, by Stephen McIntyre and Ross McKitrick, and he responded
by refusing to make public the details of his analysis.")

To understand the issues, it helps to follow the paper trail.

First of all, let's point out that the National Research council
investigated Mann's work and agreed with its findings

<quote>"I saw nothing that spoke to me of any manipulation," said one
member, Peter Bloomfield, a statistics professor at North Carolina
State University. He added that his impression was the study was "an
honest attempt to construct a data analysis procedure."</quote>

The webpage i quoted should provide sufficient materials for any
skeptic to do the necessary research themselves.

If people believe that particular arguments against Mann and the
hockey stick require additional attention, I encourage them to bring
them forward.

In AR4 the time period of the hockey stick has been extended to 1300 years.

<quote> It concludes the higher temperatures observed during the past
50 years are so dramatically different from anything in the climate
record that the last half-century period was likely the hottest in at
least the past 1,300 years.</quote>

From the (leaked draft) report we learn additional fact (figure 6.10)

The TAR pointed to the "exceptional warmth of the late 20th century,
relative to the past 1000 years". Subsequent evidence has provided
more information. However, it is very likely that average Northern
Hemisphere temperatures during the second half of the 20th century
were warmer than any other 50-year period in the last 500 years. It is
also likely that this was the warmest period in the past 1000 years
and unusually warm compared with the last 1300 years. The regional
extent of Northern Hemisphere warmth was very likely greater during
the 20th century than in any other century during the last 1300 years.
The uneven coverage and characteristics of the proxy data mean that
these conclusions are most robust over
summer, extra-tropical, land areas.


The weight of current multi-proxy evidence, therefore, suggests
greater 20th century warmth in comparison with temperature levels of
the previous 400 years, than was shown in the TAR. On the evidence of
the few new reconstructions that reach back across most, or all, of
the last two millennia, it is likely that the 20th century was the
warmest in at least the past 1300 years.

See for instance J Climate, Testing the Fidelity of Methods Used in
Proxy-Based Reconstructions of Past Climate by Michael E. Mann, Scott
Rutherford, Eugene Wahl & Caspar Ammann

While the science behind climate reconstruction may be tricky, it
seems time to lay to rest the accusations of fraud, etc against the
work by Mann and other scientists. Yet, I am always open to new
revelations relevant to this topic.

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Received on Sun, 4 Feb 2007 12:09:04 -0800

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