Global Warming Science - www.appinsys.com/GlobalWarming
[last update: 2009/11/27]
The popular global warming theory: that anthropogenic CO2 emissions have caused unprecedented global warming in the second half of the 20th century, is based strictly on the combination of two features:
If it the late 20th century warming can’t be shown to be unprecedented, then there is a major problem with the theory (there has been no warming since the 1990s, which is also becoming a problem for the theory).
The IPCC went to considerable effort to provide evidence that the warming was unprecedented. The “hockey-stick” graph produced by Michael Mann (and used by the IPCC and Al Gore) eliminated the Medieval Warm Period and the Little Ice Age in order to exaggerate the 20th century warming.
For more information on paleo-climate as well as the debunking of the hockey-stick,
Many climate scientists disagreed with the Mann / IPCC position that the Medieval Warm Period and Little Ice Age didn’t really exist. But since the IPCC is the global political master of the climate “consensus” the “unprecedented” story became official.
For example, Moberg et al, 2005 [http://www.nature.com/nature/journal/v433/n7026/full/nature03265.html]
“Here we reconstruct Northern Hemisphere temperatures for the past 2,000 years by combining low-resolution proxies with tree-ring data… According to our reconstruction, high temperatures—similar to those observed in the twentieth century before 1990—occurred around ad 1000 to 1100, and minimum temperatures that are about 0.7 K below the average of 1961–90 occurred around ad 1600. This large natural variability in the past suggests an important role of natural multicentennial variability that is likely to continue.” The following figure is from their paper [http://stephenschneider.stanford.edu/Publications/PDF_Papers/MobergEtAl2005.pdf]
The following two figures compare the Moberg 2005 figure (b) above to the IPCC hockey-stick (left) and spaghetti graph (right), showing what the IPCC is trying to obfuscate.
This IPCC position is at odds with the findings of many other scientists. For example, research at the Harvard-Smithsonian Center for Astrophysics report on a recent paper using proxies, which verifies the occurrence of the MWP: [http://cfa-www.harvard.edu/press/pr0310.html] “A review of more than 200 climate studies led by researchers at the Harvard-Smithsonian Center for Astrophysics has determined that the 20th century is neither the warmest century nor the century with the most extreme weather of the past 1000 years. The review also confirmed that the Medieval Warm Period of 800 to 1300 A.D. and the Little Ice Age of 1300 to 1900 A.D. were worldwide phenomena not limited to the European and North American continents. While 20th century temperatures are much higher than in the Little Ice Age period, many parts of the world show the medieval warmth to be greater than that of the 20th century.”
Dr. David Deming (University of Oklahoma, College of Earth and Energy) said in his testimony to congress [http://epw.senate.gov/hearing_statements.cfm?id=266543] “I had another interesting experience around the time my paper in Science was published. I received an astonishing email from a major researcher in the area of climate change. He said, "We have to get rid of the Medieval Warm Period.” The existence of the MWP had been recognized in the scientific literature for decades. But now it was a major embarrassment to those maintaining that the 20th century warming was truly anomalous.”
Climategate: On Nov 20, 2009 someone hacked a Hadley Climatic Research Unit (CRU) server and obtained emails between several prominent climate researchers (Mann, Jones, Briffa, etc.) and someone put the emails in a searchable database: [http://www.eastangliaemails.com]. The following series of emails clearly show that the “unprecedented” warming was far from certain and that the CRU climatologists tried to hide any data that indicated the actual uncertainty (bold emphasis added in emails below).
Email: Keith Briffa to Mann, Jones and others, Sep 22, 1999, (Subject: “IPCC Revisions” [http://www.anelegantchaos.org/cru/emails.php?eid=136&filename=938018124.txt])
“I know there is pressure to
Email: Phil Jones to Ray Bradley, Nov 16, 1999, (Subject: “Diagram for WMO Statement”).
“I've just completed Mike's
Nature trick of adding in the real temps
Email: Raymond Bradley to Frank Oldfield, Jul 10, 2000, (Subject: “IPCC Revisions”
“the very strong trend in the
20th century calibration
Furthermore, it may be that
Mann et al simply don't have the
Whether we have the 1000
Email: Chick Keller to Mann, Jones, Briffa, and others, Mar 2, 2001, (Subject: “Some thoughts on climate change proxy temperatures in the last 1,000 yrs” [http://www.anelegantchaos.org/cru/emails.php?eid=219&filename=983566497.txt]).
“Anyone looking at the records
gets the impression that the temperature
The community, however, in
making ensemble averages gets a much smaller
We must address the question:
One way would be to note that
the temperature amplitude (1000 - 1950)
Thus, if people simply
looked at several records they would get the
(Also, I note that most proxy
temperature records claim timing errors
Email exchange between: Michael Mann, Edward Cook and Tom Crowley, May 2, 2001, (Subject: “Hockey Stick” [http://www.anelegantchaos.org/cru/emails.php?eid=228&filename=988831541.txt]).
Cook to Mann:
“My statement that the
MWP appeared to be comparable to the
chronologies are not good at
the Esper series shows a very
strong, even canonical, Medieval Warm Period - Little
I would not claim (and nor
would Jan) that it
Email exchange between: Michael Mann and John Christy, May 23, 2001, (Subject: “IPCC” [http://www.anelegantchaos.org/cru/emails.php?eid=230&filename=990718382.txt] Mann expressed disappointment that Christy went on John Stossel’s TV show).
Christy: “I'll be very
Mann: “In one of the
pre-interviews they asked about the "Hockey Stick". I
I've been very disappointed
with what has gone
the dose of climate change
disasters that have been
Regarding the IPCC. The IPCC TAR is good, but it is not perfect nor
sacred and is open to criticism
as any document should be. …
Email from Michael Mann to Tim Osborn, Keith Briffa and others, Apr 15, 2002, (Subject: “Your Letter to Science” [http://www.anelegantchaos.org/cru/emails.php?eid=268&filename=1018889093.txt]).
“We can maintain an honest
difference about how well those points were
Email from Michael Mann to Phil Jones and others, Jun 4, 2003, (Subject: “Prospective Eos Piece?” [http://www.eastangliaemails.com/emails.php?eid=319&filename=1054736277.txt]).
“it would be nice to try to
"contain" the putative "MWP", even if we don't yet
Email exchange between Keith Briffa and Edward Cook, Apr 12, 2005, (Subject: “Review” [http://www.anelegantchaos.org/cru/emails.php?eid=310&filename=1051638938.txt]).
Briffa: “as one is honest
and open about evaluating the evidence (I have my doubts
I just don't want to get into
an open critique
Cook: “Bradley still
regards the MWP as "mysterious" and "very incoherent"
Email between Phil Jones and John Christy, Jul 5, 2005, (Subject: “This and that”
Christy: “I would like to
see the climate change happen,
to the email, text from Joe Barton (Chairman of the US House of
Representatives) to Rajendra Pachauri (Chairman of the IPCC): “in recent peer-reviewed
articles in Science, Geophysical Research Letters, Energy & Environment,
among others, researchers question the results of this work. As these
researchers find, based on the available information, the conclusions