co-chairmen of the U.S. House of Representatives subcommittee on oversight and investigations.[/I]]
Dr. Rajendra K. Pachauri, chairman,
Intergovernmental Panel on Climate Change,
Geneva, Switzerland
Dear Chairman Pachauri:
Questions have been raised, according to a Feb. 14, 2005, article in The
Wall Street Journal, about the significance of methodological flaws and
data errors in studies by Dr. Michael Mann and co-authors of the
historical record of temperatures and climate change.
We understand that
these studies of temperature proxies (tree rings, ice cores, corals, etc.)
formed the basis for a new finding in the 2001 United Nation's
Intergovernmental Panel on Climate Change (IPCC) Third Assessment Report
(TAR).
This finding -- that the increase in 20th-century northern
hemisphere temperatures is "likely to have been the largest of any century
during the past 1,000 years" and that the "1990s was the warmest decade
and 1998 the warmest year" -- has since been referenced widely and has
become a prominent feature of the public debate surrounding climate change
policy.
However, 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 concerning temperature histories -- and hence
whether warming in the 20th century is actually unprecedented -- cannot be
supported by the Mann et al. studies. In addition, we understand from the
Feb. 14 Journal and these other reports that researchers have failed to
replicate the findings of these studies, in part because of problems with
the underlying data and the calculations used to reach the conclusions.
Questions have also been raised concerning the sharing and dissemination
of the data and methods used to perform the studies.
For example,
according to the January, 2005, Energy & Environment, the information
necessary to replicate the analyses in the studies has not been made fully
available to researchers upon request.
The concerns surrounding these studies reflect upon the quality and
transparency of federally funded research and of the IPCC review process -- two matters of particular interest to the committee.
For example, one
concern relates to whether IPCC review has been sufficiently robust and
independent. We understand that Dr. Michael Mann, the lead author of the
studies in question, was also a lead author of the IPCC chapter that
assessed and reported this very same work, and that two co-authors of the
studies were also contributing authors to the same chapter....
We open
this review because the dispute surrounding these studies bears directly
on important questions about the federally funded work upon which climate
studies rely and the quality and transparency of analyses used to support
the IPCC assessment process.
With the IPCC currently working to produce a
fourth assessment report, addressing questions of quality and transparency
in the underlying analyses supporting that assessment, both scientific and
economic, are of utmost importance if Congress is eventually going to make
policy decisions drawing from this work.
To assist us as we begin this review, and pursuant to Rules X and XI of
the U.S. House of Representatives, please provide the following
information requested below on or before July 11, 2005:
1. Explain the IPCC process for preparing and writing its assessment
reports, including, but not limited to:
(a) how referenced studies are
reviewed and assessed by the relevant Working Group; (b) the steps taken
by lead authors, reviewers and others to ensure the data underlying the
studies forming the basis for key findings -- particularly proxy and
temperature data -- are accurate and up to date; and (c) the IPCC
requirements governing the quality of data used in reports.
2. What specifically did IPCC do to check the quality of the Mann et al.
studies and underlying data, cited in the TAR? Did IPCC seek to ensure the
studies could be replicated?
3. What is your position with regard to:
(a) the recent challenges to the
quality of the Mann et al. data,
(b) related questions surrounding the
sharing of methods and research for others to test the validity of these
studies, and
(c) what this controversy indicates about the data quality of
key IPCC studies?
4. What did IPCC do to ensure the quality of data for other prominent
historical temperature or proxy studies cited in the IPCC,
including the
Folland et al. and Jones et al. studies that were sources for the graphic
accompanying the Mann et al. graphic in the Summary for Policy-makers? Are
the data and methodologies for such works complete and available for other
researchers to test and replicate?
5. Explain
(a) the facts and circumstances by which Dr. Michael Mann
served as a lead author of the very chapter that prominently featured his
work, and
(b) by which his work became a finding and graphical feature of
the TAR Summary for Policy-makers.
6. Explain (a) how IPCC ensures objectivity and independence among section
contributors and reviewers,
(b) how they are chosen, and
(c) how the
chapters, summaries and the full report are approved, and what any such
approval signifies about the quality and acceptance of particular research
therein.
7. Identify the people
who wrote and reviewed the historical
temperature-record portions of the TAR, particularly Section 2.3, "Is the
Recent Warming Unusual?" and explain all their roles in the preparation of
the TAR, including, but not limited to, the specific roles in the writing
and review process.
8. Given the questions about Mann et al. data, has the Working Group I or
the IPCC made any changes to specific procedures or policies, including
policies for checking the quality of data, for the forthcoming Fourth
Assessment Report?
If so, explain in detail any such changes and why they
were made.
9. Does the IPCC or Working Group I have policies or procedures regarding
the disclosure and dissemination of scientific data referenced in the
reports?
If so, explain in detail any such policies and what happens when
they are violated.
Joe Barton, Ed Whitfield, chairmen, Subcommittee on Oversight and
Investigations