IPCC and scientific expertise
115. Given the global scale of the IPCC process,
it should be expected that it will attract the best experts. In
his evidence to us, Professor Paul Reiter raised doubts about
the extent to which this is the case.
He refers to the Second Assessment Report of Working Group II
in 1995, Chapter 18 of which is concerned with human health impacts
of warming. A significant part of this chapter discussed malaria.
Yet, according to Professor Reiter, none of the lead authors had
ever written a paper on malaria, the chapter contained serious
errors of fact, and at least one of the chapter's authors continues
to make claims about warming and malaria that cannot be substantiated.
Professor Reiter's concerns extend to the same chapter in the
Third Assessment Report of 2001, where he was initially a contributory
author. While he expresses far more confidence in this chapter
than the equivalent one in the Second Assessment Report, Professor
Reiter notes that "the dominant message was that climate
change will result in a marked increase in vector-borne disease,
and that this may already be happening". In Professor Reiter's
view, no such conclusion is warranted by the evidence, and he
speaks as a malaria specialist of more than thirty years' experience.
While nominated by the US Government to serve on the comparable
group for the Fourth Assessment Report, the next one that will
appear from IPCC, Professor Reiter learned that his nomination
had not been accepted by IPCC. Yet Professor Reiter tells us that
of the two lead authors for that chapter, one had no publications
at all and the other only five articles.
116. We cannot prove that Professor Reiter's
nomination was rejected because of the likelihood that he would
argue warming and malaria are not correlated in the manner the
IPCC Reports suggest. But the suspicion must be there, and it
is a suspicion that lingers precisely because the IPCC's procedures
are not as open as they should be. It seems to us that there remains
a risk that IPCC has become a "knowledge monopoly" in
some respects, unwilling to listen to those who do not pursue
the consensus line. We think Professor Reiter's remarks on "consensus"
"Consensus is the stuff of politics, not science.
Science proceeds by observation, hypothesis and experiment. Professional
scientists rarely draw firm conclusions from a single article,
but consider its contribution in the context of other publications
and their own experience, knowledge and speculations".
We are concerned that there may be political interference
in the nomination of scientists whose credentials should rest
solely with their scientific qualifications for the tasks involved.
IPCC and economics expertise
117. In his evidence to us, Professor Ross McKitrick
suggested that the IPCC no longer commanded the allegiance of
In scrutinising the authorship of chapters, we believe his perception
has arisen because some of the economics that was originally subsumed
in Working Group III was moved in the 2001 Report to Working Group
II. Working Group II is concerned with impacts, adaptation and
vulnerability. Its authorship is dominated by impact specialists
who tend not to be economists. The fact that the chapter that
deals with monetised benefits of warming control now appears in
that volume may explain its apparent downgrading, although we
note that this is also consistent with IPCC's desire to avoid
the politically-inspired debates over the benefit estimates. Working
Group III deals with the remaining economic issues and the amount
of economic expertise is more significant.
118. Overall, we are concerned that the IPCC
process could be improved by rethinking the role that government-nominated
representatives play in the procedures, and by ensuring that the
appointment of authors is above reproach. If scientists are
charged with writing the main chapters, it seems to us they must
be trusted to write the summaries of their chapters without intervention
from others. Similarly, scientists should be appointed because
of their scientific credentials, and not because they take one
or other view in the climate debate. The IPCC publications as
a whole contain some of the most valuable summary information
available to the world on what we know about climate change. The
standards employed are clearly very high. But this is all the
more reason to ensure that procedures are unimpeachable. At
the moment, it seems to us that the emissions scenarios are influenced
by political considerations and, more broadly, that the economics
input into the IPCC is in some danger of being sidelined. We call
on the Government to make every effort to ensure that these risks
88 Evidence from N. Nakicenovic (Vol II, pp 131-137) Back
See, for instance, evidence from R. Tol (Vol II, pp 69-77) Back
Evidence from T. Barker (Vol II, pp 78-86) Back
Evidence from P. Reiter (Vol II, pp 284-288) Back
Evidence from R. McKitrick (Vol II. Pp 262-266) Back