Questions? Call 800-624-6242
|
|
|
|
|
The following HTML text is provided to enhance online
readability. Many aspects of typography translate only awkwardly to HTML.
Please use the page image
as the authoritative form to ensure accuracy.
Page 1
Executive Summary
The U.S. government has pending before it the ratification of
the Kyoto Protocol, an agreement to limit the emissions of
greenhouse gases (GHGs), which is largely based on the threat GHGs
pose to the global climate. Such an agreement would have
significant economic and national security implications, and
therefore any national policy decisions regarding this issue should
rely in part on the best possible suite of scenarios from climate
models.
The U.S. climate modeling research community is a world leader
in intermediate and smaller1
climate modeling efforts—research that has been instrumental
in improving the understanding of specific components of the
climate system. Somewhat in contrast, the United States has been
less prominent in producing high-end climate modeling results,
which have been featured in recent international assessments of the
impacts of climate change. The fact that U.S. contributions of
these state-of-the-art results have been relatively sparse has
prompted a number of prominent climate researchers to question the
current
|
|
|
|
|
Below are the first 10 and last 10 pages of uncorrected machine-read text (when available) of this chapter, followed by the top 30 algorithmically extracted key phrases from the chapter as a whole.
Intended to provide our own search engines and external engines with highly rich, chapter-representative searchable text on the opening pages of each chapter.
Because it is UNCORRECTED material, please consider the following text as a useful but insufficient proxy for the authoritative book pages.
Do not use for reproduction, copying, pasting, or reading; exclusively for search engines.
OCR for page 1
Page 1
Executive Summary
The U.S. government has pending before it the ratification of
the Kyoto Protocol, an agreement to limit the emissions of
greenhouse gases (GHGs), which is largely based on the threat GHGs
pose to the global climate. Such an agreement would have
significant economic and national security implications, and
therefore any national policy decisions regarding this issue should
rely in part on the best possible suite of scenarios from climate
models.
The U.S. climate modeling research community is a world leader
in intermediate and smaller1
climate modeling efforts—research that has been instrumental
in improving the understanding of specific components of the
climate system. Somewhat in contrast, the United States has been
less prominent in producing high-end climate modeling results,
which have been featured in recent international assessments of the
impacts of climate change. The fact that U.S. contributions of
these state-of-the-art results have been relatively sparse has
prompted a number of prominent climate researchers to question the
current
1 An example
of what is referred to in this document as a small modeling effort
is one using a global, stand-alone atmospheric climate model at R15
(~4.5°×7.5°) resolution; an example of an
intermediate effort is one using a global, stand-alone atmospheric
climate model at T42 (2.8°×2.8°) resolution; an
example of a large or high-end modeling effort is one using a
global, coupled T42 atmospheric / 2°×2° oceanic model
(or finer resolution) for centennial-scale simulations of transient
climate change.
OCR for page 2
Page 2
organization and support of climate modeling research in the
United States, and has led ultimately to this report.
In this evaluation of U.S. climate modeling efforts, the Climate
Research Committee (CRC) was asked by USGCRP agency program
managers to address three key questions, which form the basis for
the NRC Statement of Task (Appendix B) for this report:
1. Do USGCRP agencies have a coordinated approach for
prioritizing from a national perspective their climate modeling
research and assessment efforts?
2. Are resources allocated effectively to address such
priorities? A related question that the report addresses is whether
currently available resources in the United States are adequate for
the purpose of high-end climate modeling.
3. How can the U.S. climate modeling community make more
efficient use of its available resources?
• Regarding the first question—the CRC has reached
the conclusion that, although individual federal agencies may have
established well-defined priorities for climate modeling research,
there is no integrated national strategy designed to encourage
climate modeling that specifically addresses, for example, the
objectives of the USGCRP, the needs for comprehensive contributions
to the IPCC science base, and the priorities developed by the CRC
in its chapter in the Board on Atmospheric Sciences and Climate's
report, Atmospheric Sciences Entering the Twenty-First
Century (NRC, 1998a). We suggest that the science-driven
climate modeling agenda, which has been largely shaped by
individual investigators, has been reasonably effective in
advancing the frontiers of science, but has not been adequately
responsive to the immediate needs of the broader community (e.g.,
the “impacts” and “policy”
communities).
• With respect to the second question—we find that,
compared with intermediate and smaller modeling efforts,
insufficient human and computational resources are being devoted to
high-end, computer-intensive, comprehensive modeling, perhaps
in
OCR for page 3
Page 3
• part because of the absence of a nationally
coordinated modeling strategy. Consequently, in contrast to
some of the foreign modeling centers, U.S. modeling centers have
found it difficult to perform coupled atmosphere-ocean climate
change scenario simulations at the spatial resolutions relevant to
certain national policy decisions (e.g., finer than 500 km ×
800 km). The recognized strengths of U.S. intermediate modeling
capabilities (see, e.g., the sizable contributions from the U.S.
coarse-resolution climate modeling efforts in the IPCC reports)
have not been effectively harnessed in the development of high-end,
U.S.-based models. For instance, leading Earth system modeling
efforts in the United States suffer from a computationally limited
ability to test and run models in a timely fashion. The ability of
the climate community to acquire state-of-the-art mainframes is
severely hampered by a Department of Commerce “antidumping
order” prescribing a financial penalty in excess of 400
percent on the purchase price of the world's most powerful
commercial supercomputers, which are Japanese in origin. The
climate community has not been provided with the financial or
computational resources to overcome this barrier and has,
therefore, been unable to fully capitalize on the scientific
potential within the United States. Not only is insufficient access
to powerful computers hampering scientific progress in
understanding fundamental climate processes, it is also limiting
the ability to perform simulations of direct relevance to policy
decisions related to human influences on climate. However, at
least as important as the insufficiency of computing resources
are the lack of national coordination and insufficient funding of
human resources.
• Regarding the third question—the CRC finds that:
1. A set of national goals and objectives that are agreed to
by the USGCRP agencies is essential.
2. A concerted effort by the relevant agencies is needed to
establish a coordinated national strategy for climate
modeling.
3. In order to optimally use existing scientific
capabilities, adequate resources, including greatly
improved
OCR for page 4
Page 4
supercomputing capabilities, need to be provided to the
climate modeling community.
4. The reliance of the United States upon other countries for
high-end climate modeling must be redressed.
In order to avoid the aforementioned problem regarding priority
setting, the USGCRP could assume increased responsibility for
identifying, from an interagency perspective, any gaps or
imbalances in the research priorities established by the individual
agencies. At present, however, this is made difficult because some
agencies have excluded from their USGCRP budgets the computational
and human resources to support comprehensive, coupled
atmosphere-ocean climate modeling efforts on a par with those in
several foreign countries. Although an entirely top-down
management approach for climate modeling is viewed as undesirable,
national economic and security interests nevertheless require a
more comprehensive national strategy for setting priorities, and
improving and applying climate models. An effective national
approach to climate modeling should ensure that available resources
are allocated appropriately according to agreed upon science
research and societal priorities and are efficiently utilized by
the modeling community. We acknowledge that justification for and
design of such a strategy would require a more complete evaluation
of the current status of climate modeling in the United States than
was possible in developing this report. Development of such a
strategy should take place with full involvement of climate
modelers within academia and the national climate research centers,
along with users of climate modeling results and agency program
managers.
Climate modeling in the United States promotes a healthy
competition among various groups, but without better coordination
of research among national laboratories and between them and the
academic community, it may be difficult to optimally utilize
available human and high-end computer resources. In particular,
standardization of model output, model evaluation tools, and
modular programming structures can facilitate model development and
minimize duplication of effort, with the possibility that prudent
standardization may yield some cost savings. High-end modeling
coordination could also be
OCR for page 5
Page 5
enhanced through refereed workshops to discuss the pertinent
scientific and associated societal issues and to recommend
priorities. Effective collaborative linkages between process
studies and modeling groups should also be encouraged to facilitate
the difficult task of developing, implementing, and testing new
model parameterizations. In addition, increased coordination of
research-based and operational modeling activities will help ensure
that expertise in these two communities is shared. These are but a
few of the types of coordinating activities that should be
vigorously and consistently pursued.
The CRC finds that the United States lags behind other
countries in its ability to model long-term climate change.
Those deficiencies limit the ability of the United States:
1. to predict future climate states and thus:
a) assess the national and international value and impact of
climate change;
b) formulate policies that will be consistent with national
objectives and be compatible with global commitments;
2. to most effectively advance understanding of the underlying
scientific issues pertaining to climate variability and change.
Although collaboration and free and open information and data
exchange with foreign modeling centers are critical, it is
inappropriate for the United States to rely heavily upon foreign
centers to provide high-end modeling capabilities. There are a
number of reasons for this, including the following:
1. U.S. scientists do not necessarily have full, open, and
timely access to output from European models, particularly as the
commercial value of these predictions and scenarios increases in
the future.2
2. Decisions that might substantially affect the U.S. economy
might be made based upon considerations of simulations (e.g.,
nestedgrid runs) produced by countries with different priorities
than those of the United States.
2U.S.
researchers, however, do currently have access to output from most
simulations of transient climate change produced by foreign
models.
OCR for page 6
Page 6
3. If U.S. scientists lose involvement in high-end modeling
activities, they may miss opportunities to gain valuable insights
into the underlying processes that are critical to subsequent
modeling investigations. In this regard the issue of accessibility
is much more than just a commercial and political issue; in order
to most effectively advance the science in the United States,
researchers need to have access to both model output and the models
themselves to iteratively diagnose the output, advance knowledge of
climate, and improve the models' predictive capabilities.
4. There are currently relatively few modeling centers anywhere
in the world capable of producing moderate resolution (e.g.,
250–300 km grid spacing), transient climate simulations. The
differences in simulated climate produced by each of these models'
different structures help to bound the range of outcomes that the
climate system might produce given a certain forcing scenario.
Thus, the state of climate modeling throughout the world is such
that the addition or removal of even a single model could affect
the confidence levels assigned to certain scenarios of future
climate change. In other words, not only would the United States
benefit from enhancements in its modeling capabilities, the
international community would benefit from these efforts as well.
The marginal benefits from only modestly increased investments in
comprehensive models in the United States could be very large,
because, if properly coordinated, the enhanced emphasis on highend
modeling could be built upon the excellent existing U.S. strength
in small and intermediate modeling.
Thus, to facilitate future climate assessments, climate treaty
negotiations, and our understanding and predictions of climate, it
is appropriate to develop a national climate modeling strategy that
includes the provision of adequate computational and human
resources and is integrated across agencies.
Representative terms from entire chapter:
modeling efforts
