Response of the New Zealand Climate Science Coalition
to comments by Dr. David Wratt - Letter
(Chair, New Zealand Climate Committee, Royal Society of New Zealand)
Important Note:
This is the response that the Royal Society of New Zealand
declined to publish on its website, where Dr Wratt posted his
comments.
We thank Dr. Wratt for his comments (Science Alert 433, July 27) on our letter
of July 20 (Science Alert 432). This letter was in correction of Dr. Jez Watson's
misinterpretation (Science Alert 431, July 13) of the reasons behind our July
21 letter to all parliamentarians - in which we recommended that the
government convene a Royal Commission on Climate Change.
Dr. Wratt takes particular issue with our assertion that “the science is not
settled”. He proposes that some reports that we cite "actually support the
contention that human activities are affecting the climate system", something
that we have never denied, and asserts that he draws very different
inferences from these reports than we do. Dr. Wratt concludes by
commending the advice given by the IPCC, and implies that IPCC
recommendations should continue to be the sole basis for New Zealand’s
climate policy.
We do not challenge Dr. Wratt’s evident belief that human activities may be
affecting climate, but that belief does not rebut any of the recommendations
that we have made to Parliament, and nor is it relevant to our observation
that the science is not settled.
Our letter to parliamentarians stated that it is not known with certainty how
much of Earth's continual climate change results from human activities, and
how much from natural changes and cycles. Also, that it remains unknown
whether any presumed human-caused changes will be more harmful than
beneficial for the Earth as a whole. Dr. Wratt does not contest these points.
Accordingly, we do not understand his assertion that he draws very different
inferences than us from the facts to hand.
Our detailed response to Dr. Wratt's letter (attached) does not address the
substantive issue of the need for national climate change policies to have a
sound basis in economics and diplomacy, as well as in science. These matters
are outlined more fully in the parts of our original statement that Dr. Wratt has
chosen to ignore (see https://www.climatescience.org.nz/assets/
2006726914350.OpenLetterMPs21July..pdf).
We provide in our response, inter alia, a summary of criticisms that have been
levelled against the IPCC since the mid-1990s, especially of its inadequate
quality assurance, criticisms to which that organization has failed to respond
adequately. We conclude that the IPCC is not a satisfactory body to provide
New Zealand with exclusive advice towards the setting of national climate
policy.
Finally, we reiterate our recommendation for a wide-ranging investigation by
an independent Royal Commission into climate change as it affects New
Zealand. We also repeat our request that the Royal Society support our call
for the establishment of such a Commission.
Scientific progress is achieved by the application of the scientific method and
impartial enquiry, rather than by appeals to authority under the slogan that
"the science is settled".
Professor Augie Auer, BSc (Meteorology), MSc (Atmos. Sci.), CCMAMS
(Chair, NZCSC Science Panel), on behalf of the New Zealand Climate Science Coalition.
Rear Admiral (ret.) Jack Welch, CB
(Chairman, NZCSC)
and
Professor Bob Carter, Bsc Hons. (Otago), PhD (Cantab.), Hon. Fellow RSNZ
Associate Professor Chris de Freitas, PhD
Mr. Roger Dewhurst, BSc Hons., M.App.Sc (Eng. Geol. & Hydrogeol.)
Mr. Terry Dunleavy, MBE, FWINZ
Dr. Vincent Gray, PhD, FNZIC
Mr. Warwick Hughes, MSc Hons.
Mr. Bryan Leyland, MSc, FIEE, FIMechE, FIPENZ
Dr. Alan Limmer, PhD, FNZIC
Dr. Bill Lindqvist, BEng. (Otago), BSc Hons. (Econ. Geol.), PhD (Imperial
Coll.)
Mr. Owen McShane, B.Arch., Dip T.P, M.C.P.
Mr. Leighton Smith, Broadcaster, Auckland
Dr. Gerrit J. van der Lingen, PhD (Geology), BSc, MSc, MGSNZ
Response of the Climate Science Coalition
to comments by Dr. David Wratt - Discussion
(Chair, New Zealand Climate Committee, Royal Society of New Zealand)
This document contains a detailed response to comments made by Dr. Wratt
in Science Alert 433 (July 27) on an earlier letter of ours in Science Alert 432
(July 20). The matters discussed all arise from the recommendation for a
Royal Commission on Climate Change, contained in a July 21 letter from the
Coalition to all parliamentarians.
The comments have been numbered and italicized for ease of reference.
Rather than restating the Coalition’s entire argument, our response is
restricted to the particular points raised by Dr. Wratt.
Yes; and note “large enough to cause concern”. The Coalition does not deny
the possibility of human-caused global climate change, but merely observes
that any such effect has not yet been measured and therefore is likely to be
small.
Study of the geological record of climate reveals many instances of natural
changes of a speed and magnitude that would be hazardous to human life and
economic well being should they be revisited upon today’s planet. Many of
these changes are unpredictable, even in hindsight. That such natural changes
will occur again in the future, both coolings and warmings, is certain. To focus
on the chimera of human-caused greenhouse warming while ignoring real
threats posed by the natural variability of the climate system itself is selfdelusory.
Therefore, nothing that the Coalition has said should be construed as denying
the need for sensible planning for future natural climate hazards in New
Zealand, in a manner analogous to contingency planning for other natural
phenomena such as earthquakes and volcanic eruptions. When and if
substantive human-caused climate change can be demonstrated empirically, it
can and should be included in the planning response.
The Coalition has never denied that human development can have an effect
on local climate, nor that the sum of such local effects represents a
hypothetical global signal. The key issues that remain, however, are: (i)
whether any human global signal can be measured, and, if so, (ii) whether it
might represent dangerous change outside of the range of natural variability.
These matters remain undetermined.
Note that we have elaborated on these matters – the uncertainty about how
much the global climate is changing, and how much of the change might result
from human influence – in reasons 1, 2, 4, 5, and 7 of our open letter to
Parliament.
The IPCC (2001, p. 61) opinion that we quoted is:
"The fact that the global mean temperature has increased since the
late 19th century and that other trends have been observed does not
necessarily mean that an anthropogenic effect on the climate system
has been identified. Climate has always varied on all time-scales, so
the observed change may be natural. A more detailed analysis is
required to provide evidence of a human impact."
Dr. Wratt suggests that the meaning of this quotation has been compromised
by being removed from context. In contrast, to us the quotation seems
crystal-clear in any context, and it remains as true today as when it was
written. We therefore reassert it here in its own right.
In any case, Dr. Wratt's comment is irrelevant, since nowhere have we
alleged that the IPCC denies the existence of evidence for a human impact on
climate, nor have we implied that such evidence is not discussed elsewhere by
IPCC (see 4 below).
The 3AR contains seven main arguments for a human impact on global
climate. We have listed these at Attachment A, and added a counterbalancing
or explanatory comment for each.
Earth is a dynamic planet. Its climate is constantly changing, and its
lithosphere, biosphere, atmosphere and oceans incorporate many complex,
homoeostatic, buffering mechanisms.
The evidence for “climate change” adduced by the IPCC, which we discuss in
Attachment A, is as yet consistent with natural change. Evidence for human
attribution is circumstantial, and, despite intensive research, no necessary
global connection with human causation has yet been established for any of
the climatic phenomena listed by the IPCC. Conversely, plausible natural
explanations exist for all of them.
What the scientific method requires is a testable hypothesis capable of
distinguishing between the competing explanations for observed events. In the
absence of a conclusive test, there is doubt. That doubt cannot be eliminated
simply by making claims that “the science is settled”.
We thank Dr. Wratt for drawing attention to the fact that we provided the
wrong web address for the National Academy of Sciences report. A correct
link is: http://newton.nap.edu/catalog/11676.
The NAS report does indeed relate to the question that we raised. For it rebuts
the evidence that the IPCC relied on for its claim that the late 20th century
warming reached the greatest magnitude of any warming for the last 1,000
years. This claim was then in turn endorsed uncritically by NIWA and the N.Z.
National Climate Committee.
Even now, Dr. Wratt appears to be defending Mann et al.’s work rather than
acknowledging its deficiencies and modifying his views accordingly. As of July
31 2006, NIWA - above Dr. Wratt's name - continues to present the hockeystick
graph to the public on its website, at http://www.niwascience.co.nz/ncc/
clivar/variations
The NAS (2006) report is important because it confirms criticisms by others of
Mann et al.’s (1998; 1999) research. It also shows that the IPCC was unable to
detect the critical weaknesses in the Mann study, or to respond effectively
when doubts were raised about the validity of the research.
Though useful in these ways, the NAS report nonetheless has a major
limitation - which it shares with many other IPCC-related studies - in that it
considers only a very short period of climatic history.
Given the well-established millennial climate cycle of probable solar origin
(e.g. Bond et al., 1997, 2001), proxy time-series which rarely go back past
1,000 years do not support clear comparisons of the late 20th Century Warm
Period with the immediately prior Medieval and, still less, the Roman Warm
Period. In turn, only extremely limited conclusions regarding the context of
modern climate change can be drawn from comparisons across such a short
time series.
The eminence of the NAS Report’s authors, which we too respect, is
nonetheless of less importance than the soundness of their conclusion that the
Mann et al. (1998, 1999) research is flawed. Confidence in the correctness of
this NAS judgment is high because it is consistent with the original criticisms
made of Mann et al.’s work by McIntyre & McKitrick (2003, 2005 a,b,c,d), and
with the parallel but independent analysis of Wegman et al. (2006).
Yet, if Dr. Wratt’s confidence in these scientists is so high, why does NIWA still
publicly endorse the research study that they and others have discredited?
Vague assertions like this are often made, but seldom explained in detail.
They appear intended mainly to distract from the obvious fact that the IPCC
put the hockey stick graph forward as a primary line of evidence of
exceptional (and therefore human-caused) late-twentieth century warming.
Now that the hockey stick has been discredited, it appears that IPCC authors
want to say that it was never important in the first place.
Furthermore, while it has asserted that paleoclimatic reconstructions are not
important for proving anthropogenic global warming, the NAS panel fails to
commit itself to identifying what is important. The panel devotes a little less
than two pages out of its 157 page-long report to listing the “multiple lines of
evidence” for human-caused warming, and those that are listed turn out to be
closely similar to IPCC orthodoxy (Attachment A). Without more elaboration
by Dr. Wratt, we remain ignorant as to which argument constitutes the
“primary evidence” for human-caused global warming. The NAS report also
fails to identify any “primary evidence”, despite its intriguing - and
challengeable - comment (p.28) that “the attribution of the recent global
warming to human activities does not rest solely or even principally upon
paleoclimate evidence”.
As a matter of scientific method, evidence in favour of a hypothesis, even if
persuasive, is not proof unless alternative plausible explanations can be
eliminated. It is quite clear that the NAS report does not provide conclusive
scientific evidence in favour of human-caused global warming, i.e. the science
is not settled.
We have discussed these issues in more detail in Attachment A. And, as the
late John Daly noted of similar statements in an earlier NAS climate report:
“The (2001) NAS committee made many assertions, none of which they
chose to justify or explain other than to state it was “their view” - as if
their mere authority as representing the National Academy of Science
were enough to prevail in the argument.
Well it isn’t. The days when mere ‘authority’ could win an argument or
debate are long gone. Such deference is more characteristic of a
medieval priesthood, not a modern science where every important
claim must be justified and explained.
Only evidence counts in this modern world.”
It is not clear what “general thrust” Dr. Wratt is referring to here, nor that any
part of Mann et al.’s research remains valid - as he seems to assume.
Dr. Wratt has missed the essential point that the NAS report sets down a
series of methodological critiques (concerning flawed statistical practice and
use of contaminated data) based on its review of the Mann et al. work. These
critiques apply to the entire list of paleoclimate reconstructions cited by the
NAS panel, not merely to Mann’s. The lack of independence among these
studies was subject to explicit criticism in the Wegman report (2006) as
follows:
“We found that at least 43 authors have direct ties to Dr. Mann by
virtue of coauthored papers with him. Our findings from this analysis
suggest that authors in the area of this relatively narrow field of
paleoclimate studies are closely related. Dr. Mann has an unusually
large reach in terms of influence and in particular (to) Drs. Jones,
Bradley, Hughes, Briffa, Rutherford and Osborn. Because of these
connections, independent studies may not be as independent as they
might appear on the surface”.
In his evidence to the Congressional Energy and Commerce Committee,
Stephen McIntyre (2006) comments that the other temperature
reconstructions cited by the NAS had not been audited or replicated by the
review panel. He adds that “Having examined most of them closely, I do not
believe that any of them provide robust or reliable information on relative
medieval-modern (temperature) levels”.
McIntyre also presented specific evidence that adhering to one single
recommendation from the NAS panel, that bristlecone pine series should be
avoided, would suffice to overturn the findings of all the paleoclimate
reconstructions adduced in support of Mann’s conclusions in the NAS report
We would welcome clarification from Dr. Wratt as to which conclusions of Mann
et al.'s study he believes to have survived these comprehensive criticisms. We
would also welcome his explanation of why the IPCC's peer review processes
failed to identify the deficiencies in the hockey-stick research.
These are unremarkable conclusions that did not require an NAS Report for
their substantiation.
The IPCC had made a sweeping claim about the uniqueness of late 20th
century climate in the context of the past 1000 years: the NAS effectively
dismissed this claim by shortening it to a 400-year interval which was never at
issue. Furthermore, they might just as easily have stated that temperatures at
many, but not all, individual locations were higher during at least one interval
in the Medieval era compared to the present.
Many hundreds of published research papers have identified a period of cold
climate - the Little Ice Age - that lasted intermittently between about 1450 and
1860 (e.g. Soon and Baliunas, 2003). Scientific enquiry has yet to disprove
the hypothesis that 20th century warming represents mainly natural
variability, including climatic recovery from the Little Ice Age.
Furthermore, given the existence of the natural millennial climate cycle
referred to in 5 above, the probable correspondence of late 20th Century
warming with one of the warm nodes of this cycle made it very likely that
temperatures in the years around 2000 AD would reach short-term historic
highs.
Such a pattern of recent high average global temperatures therefore bears no
necessary relation whatsoever to hypothetical human-caused global warming.
This is not to deny the possibility or even plausibility of a human effect. What
we do deny is the claim that "the science is settled" regarding either the
magnitude, or perhaps even the sign, of any human effect.
The reference to a “political committee” sounds as if it is intended as a slight
against the credentials or motivations of the members of the committee. The
NAS panel was also commissioned by a “political committee”—the US House
Science Committee. Dr. Wratt does not hold this against the NAS panelists in
light of their credentials for the study they undertook. Likewise, he has no
basis for questioning or making insinuations against the credentials of Dr.
Wegman, his coauthors, or the extensive list of reviewers who were consulted
during the Wegman Committee’s work.
It is not a valid criticism or limitation of Wegman that he focused on one topic.
The work that was under review - the Mann et al. hockey stick temperature
reconstruction - was a fundamental part of the argument made in the IPCC
3AR for a discernible human influence on global climate. Indeed, it is arguably
the single piece of research that the IPCC and climate change activists have
used most widely to influence public opinion towards the alleged danger of
human-caused warming. For instance, the hockey stick graph was included as
a large banner backdrop at Sir John Houghton’s public launch of the Third
Assessment Report.
And the view of the genuinely independent expert reviewers on this work
(Wegman et al., 2006) was:
“In general, we found the writing in MBH98 and MBH99 to be somewhat
obscure and incomplete and the criticisms by McIntyre & McKitrick to
be valid. The reasons for setting 1902-1995 as the calibration period
presented in the narrative of MBH98 sounds plausible, and the error
may easily be overlooked by someone not trained in statistical
methodology. We note that there is no evidence that Dr. Mann or any
of the other authors in palaeoclimate studies have had significant
interactions with mainstream statisticians.”
The materials at hand include peer-reviewed journal articles, a panel report
by the NAS and an independent report by three statisticians, led by the chair
of the US National Academy of Sciences Committee on Theoretical and Applied
Statistics.
In trying to deny the validity of these materials Dr. Wratt cites an unrefereed
weblog posting by the author (Mann) whose work was subject to criticism. In
any other context Dr. Wratt would dismiss an appeal to an unpublished
internet posting in response to published articles and NAS reports. His usage
of the RealClimate posting in this context is pointlessly argumentative and
betrays an unwillingness to grapple seriously with valid criticisms.
McIntyre & McKitrick (2003, 2005a,b,c,d), the NAS report (2006) and the
Wegman report (Wegman et al., 2006) have all independently ascertained that
Mann’s PC method produces spurious hockey-stick shapes from a combination
of (i) inappropriate centring of the data series, (ii) non-random or biased
selection of small data samples, and (iii) inclusion in the calculation of proxies
that are known not to reflect a reliable temperature signal (notably, bristle
cone pine datasets).
The re-interpeted graph placed on RealClimate was only corrected for error
(i). It still incorporates the bristle cone pine data series, and still does not pass
the tests of statistical significance originally claimed to have been used.
Removal of the bristlecones destroys the hockey stick shape—a point
acknowledged by the NAS panel (p. 107).
The NAS Report (p. 50) also stated that inferring temperature from bristle
cone pine ring data is fraught with uncertainty:
“In old age, these trees can assume a “strip bark” form, characterized
by a band of trunk that remains alive and continues to grow after the
rest of the stem has died. Such trees are sensitive to higher
atmospheric CO2 concentrations (Graybill and Idso, 1993), possibly
because of greater water-use efficiency (Knapp et al., 2001, Bunn et
al. 2003) or different carbon partitioning among tree parts (Tang et al.,
1999). ....... Further evidence comes from a recent review of data for
mature trees in four climatic zones, which concluded that pine growth
at treeline is limited by factors other than carbon (Körner 2003). While
‘strip bark’ samples should be avoided for temperature reconstructions,
attention should also be paid to the confounding effects of
anthropogenic nitrogen deposition (Vitousek et al. 1997), since the
nutrient conditions of the soil determine wood growth response to
increased atmospheric CO2 (Kostiainen et al. 2004).”
In conclusion, the RealClimate posting failed to address the substance of the
criticisms presented by McIntyre and McKitrick, and upheld by the NAS and
Wegman panels.
The NAS and Wegman reports did review a range of peer-reviewed evidence.
In doing so they found the IPCC had made a serious blunder, and in the words
of one NAS panellist, had sent a “very misleading message” by focusing on
the hockey stick. None of the procedures that led to this problem have been
corrected, so it is unacceptable for Dr. Wratt to close his eyes to the situation
and counsel continued reliance on the IPCC as a competent and unbiased
source of advice.
We summarize some of the historic criticisms that have been made of the
IPCC at Attachment B.
IPCC has not implemented significant changes to its procedures in response to
these criticisms. Compounding this problem, its authority as a contemporary
source of accurate advice on climate change has been thrown into question by
two recent, thorough investigations into climate change science by the Select
Committee of Economic Affairs of the UK House of Lords (2005) and the US
Congressional Committee of Energy and Commerce (2006).
The House of Lords Committee concluded that:
“We can see no justification for an IPCC procedure which
strikes us as opening the way for climate science and
economics to be determined, at least in part, by political
requirements rather than by evidence. Sound science cannot
emerge from an unsound process”, adding also that “we are
concerned that there may be political interference in the
nomination of scientists to the IPCC”.
The procedure to which their Lordships were referring is the
way in which government bureaucrats, and not scientists,
control the wording of the text of the IPCC’s influential
Summary for Policymakers volumes.
Stephen McIntyre (2006), in his Testimony to the US
Congressional Committee, points out that:
“Scientific overviews, such as ones produced by IPCC ... are
nearly entirely based on literature review rather than
independent due diligence”.
This, of course, is precisely the reason that the 3AR failed to
detect the falseness of the Mann et al. (1998, 1999) “hockey
stick” depictions of recent climate history, and instead made
these a centre piece of IPCC claims of a dangerous human
influence on climate.
Wegman (2006), in his evidence to the same Committee, lists as
his first recommendation that:
“Especially when massive amounts of public monies and human
lives are at stake, academic work should have a more intense
level of scrutiny and review. It is especially the case (our
emphasis) that authors of policy-related documents like the
IPCC report, ’Climate Change 2001: The Scientific Basis’,
should not be the same people as those that constructed the
academic papers”.
It is also the case that the forthcoming Fourth Assessment
Report of the IPCC has been mostly written, edited and
unsatisfactorily refereed by scientists whose audit and due
diligence capabilities are blunted in the very way that Wegman
has forensically pinpointed.
Therefore we place less store than does Dr. Wratt on the accuracy and
impartiality of advice rendered by the IPCC, especially that contained in its
“Advice to Policymakers” volumes.
In addition to that, however, it has already been announced that the 4AR will
use the same fundamentally misleading socioeconomic scenarios that were
deployed in 3AR (cf. Attachment B). Given also the lack of procedural change
in IPCC quality control methods, there is no assurance that even the detailed
Working Group Reports of 4AR will not contain science or economics that is as
unsound as was the Mann et al. hockey stick research.
To question thus the authority of IPCC pronouncements is not to question the
integrity, excellence or commitment of the many scientists who contribute to
its technical papers. The problem is that technical contributions require
evaluation for their usefulness in policy formulation, yet there is no objective
basis for determining how such evaluation should be done. Obviously, full
scientific objectivity cannot be maintained once politics have intruded.
No human organisation is flawless. This is why appeals to the authority of an
organisation, including the IPCC, are inimical to the advance of scientific
understanding.
It is self-evident that New Zealand’s sovereign and economic interests are not
being well served by subservient reliance on the advice of a flawed
international body, over which we lack significant control.
The New Zealand public is entitled to accurate and truthful advice on climate
change that is tailored to both our regional geographic setting, and to political
and economic reality. What is needed is less advocacy from the government's
advisers in defence of IPCC or other authority, and for the assertion that 'the
science is settled', and a greater willingness to apply the scientific method in
the context of New Zealand’s particular circumstances.
The Coalition believes that the establishment of a Royal Commission would be
the most cost-effective first step towards achieving these ends.
The main inferences that we drew in our letter to parliamentarians of July 21
remain. They are:
(i) that the magnitude of likely human-caused global climate change
cannot be measured, has not yet been shown to have a high risk of
being dangerous, and remains under strong dispute amongst equally
qualified scientific groups;
i.e. the science of climate change is far from settled;
(ii) that the benefits of NZ having signed the Kyoto accord, or of the
institution of any other policies intended to avert global climate
change (such as a carbon tax), are entirely unclear, and under
strong challenge;
i.e. the economics and likely effectiveness of climate change
mitigation measures are far from settled; and
(iii) that because of the many special interests involved (amongst which
number energy and mining companies, environmental consultants,
environmental and other NGOs, scientists employed to research
climate change, government bureaucrats and departments, local and
regional councils, and national politicians), the best and perhaps only
way to get dispassionate advice on this vexed issue is to convene a
Royal Commission of enquiry.
New Zealand's participation in Kyoto will cost at least $1
billion more than originally estimated; seeking impartial
advice as to the benefit seems only wise.
Professor Augie Auer, BSc (Meteorology), MSc (Atmos. Sci.), CCMAMS
(Chair, NZCSC Science Panel), on behalf of:
Rear Admiral (ret.) Jack Welch, CB
(Chairman, NZCSC)
and
Professor Bob Carter, Bsc Hons. (Otago), PhD (Cantab.), Hon. Fellow RSNZ
Associate Professor Chris de Freitas, PhD
Mr. Roger Dewhurst, BSc Hons., M.App.Sc (Eng. Geol. & Hydrogeol.)
Mr. Terry Dunleavy, MBE, FWINZ
Dr. Vincent Gray, PhD, FNZIC
Mr. Warwick Hughes, MSc Hons.
Mr. Bryan Leyland, MSc, FIEE, FIMechE, FIPENZ
Dr. Alan Limmer, PhD, FNZIC
Dr. Bill Lindqvist, BEng. (Otago), BSc Hons. (Econ. Geol.), PhD (Imperial
Coll.)
John McLean, BArch (Melbourne)
Mr. Owen McShane, B.Arch., Dip T.P, M.C.P.
Mr. Leighton Smith, Broadcaster, Auckland
Dr. Gerrit J. van der Lingen, PhD (Geology), BSc, MSc, MGSNZ
Dr. Bryce Wilkinson, PhD (Econ.), BSc Hons. (Chemistry), MCom. (Econ.)
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