Introduction and Background
During its first 10 years of operation, the U.S. Global Change Research Program (USGCRP) has advanced our understanding of the Earth's ever-changing physical, chemical, and biological systems and the growing human influences on these systems. On the basis of this knowledge we can now focus attention on the critical unanswered scientific questions that must be resolved to fully understand and usefully predict global change. Such capability is increasingly important for developing our economy, protecting our environment, safeguarding our health, and negotiating international agreements to ensure the sustainable development of the United States and the global community of nations. There are now compelling reasons for scientific knowledge to guide and respond to policy options, both current and future. Clearly, we must delineate research pathways that will enlarge our understanding of changes in the global environment, including climate change. At the same time we need to reduce uncertainties in the projections that shape our decisions for the future. For all these reasons it is essential that the USGCRP continue to receive strong financial support and continue to provide continuing strong scientific leadership. To be effective the USGCRP must be based on a sound scientific strategy, focused on key unanswered scientific questions, using a correspondingly balanced strategy for supporting observational, data management, and analysis activities.
On the basis of the continuing reviews of the Committee on Global Change Research (CGCR) and those of its collaborating bodies, the committee reaffirms the achievements and significance of the USGCRP while finding that the Program must now be revitalized, focusing its use of funds more effectively on the
principal unanswered scientific questions about global environmental change. This goal demands that funding and efforts be directed toward a coherent and coordinated suite of research activities and supporting observational, data management, and modeling capabilities, all aimed at imperative research objectives and clearly defined scientific questions. A sharply focused scientific strategy and a coherent programmatic structure are both critically needed. This report seeks to provide a framework for such a strategy and structure. The elaboration and implementation of this scientific strategy and programmatic structure will be the principal challenge for global change research over the course of the next decade.
Long before the industrial revolution, human activity began to alter the Earth's environment. However, only in this century has the scale of such alterations become global in scope; moreover, the rate of these recent changes is enormously high compared with the historical record. Today, on the threshold of a new millennium, it is clear that humans are inducing environmental changes in the planet as a whole. In fact, the human fingerprint is abundantly seen on the global atmosphere, the world oceans, and the land of all continents. This insight has brought about profound changes in the goals, priorities, and processes of both science and government.
Recognition that humans are causing global changes in the biology, physics, and chemistry of the environment—changes with immense significance for human society and economy—has prompted the U.S. government, and other national governments, to act. In 1990, Congress established the USGCRP to carry out an organized, coherent attack on the scientific issues posed by global environmental change.
The USGCRP had its principal roots in the 1980s, as both scientists and the public became increasingly aware of the links among human activities, current and future states of the global environment, and human welfare. The most immediate concerns were human-induced climate change, stratospheric ozone depletion from industrial emissions, and emerging evidence that the Earth's biogeochemical system was being perturbed by a broad range of human actions.
Some of the many antecedents of the USGCRP were seen still earlier. In the 1970s a convergence of long-standing scientific concerns (see below) and a series of climatic events led to the first World Climate Conference and to the establishment of the U.S. National Climate Program and the World Climate Program.1 In parallel, beginning in the mid-1970s, the U.S. Department of Energy (DOE) organized a major research program to assess the consequences of fossil-based energy production. Workshops chaired by the late Roger Revelle outlined a broad
multidisciplinary research agenda closely congruent with today's USGCRP, including a strong emphasis on the carbon cycle, the role of ecosystems, and human dimensions research.2
“If we believed that the Earth was a constant system in which the atmosphere, biosphere, oceans, and lithosphere were unconnected parts, then the traditional scientific fields that study these areas could all proceed at their own pace treating each other's findings as fixed boundary conditions. However, not only is the Earth changing even as we seek to understand it—in ways that involve the interplay of land and sea, of oceans, air, and biosphere—we cannot even presume that global change will be uniform in space and steady in time . . . . Needed to resolve this complex of change and interplay are coordinated efforts between adjacent scientific disciplines and programs of synoptic observations focused on common, interrelated problems that affect the Earth as a whole.”—National Research Council (1983a)
The immediate precursor of the USGCRP, however, was a workshop sponsored by the National Aeronautics and Space Administration (NASA) in 1982 on global habitability, which was led by Richard Goody.3 This workshop emphasized the fact that in many critical respects the ocean, atmosphere, and biosphere function together on long timescales as a single integrated system, a system requiring interdisciplinary research and observing programs of global scope and decadal duration. The stage had been set for encouraging similar fully integrated, long-term research by the Global Atmospheric Research Program, a program that itself arose from a seminal study by the National Research Council (NRC)4 and laid the groundwork for the World Climate Research Program. The shaping of such comprehensive endeavors, which arose by recognizing the importance of chemical and biological as well as physical factors in the global system, also led to the establishment of the International Geosphere-Biosphere Program of the International Council of Scientific Unions (subsequently renamed the International Council for Science). The priorities and nature of this program, from a U.S. perspective, were laid out in a sequence of NRC reports.5 Most recently, human components in global environmental change have been given wider recognition in the creation of the International Human Dimensions Program on Global Environmental Change.
The goal of the International Geosphere Biosphere Program (IGBP) is “—to describe and understand the interactive physical, chemical and biological processes that regulate the total Earth system, the unique environment that it provides for life, the changes that are occurring in this system, and the manner in which they are influenced by human actions.”—International Council of Scientific Unions (1996)
Still other precursors to the USGCRP include two reports in the 1980s by the NASA-sponsored Earth System Sciences Committee (ESSC),6 which sought to define a new and revolutionary scientific discipline of Earth system science. In keeping with the Goody report7 and the 1986 NRC report, Global Change in the Geosphere-Biosphere,8 this new discipline would be dedicated to study of the Earth as an integrated system of interacting components. Its goal would be to obtain “a scientific understanding of the entire Earth system on a global scale.” 9 The emergence of a science of the Earth system, moreover, offered a promise of knowledge that would be valuable to decision makers addressing global habitability.
Prominent in the ESSC documents was a recommendation for an Earth Observing System to provide long-term global observations, with an emphasis on the long-term continuity of observations, both satellite and in situ. The importance of long-term records reflected the audience for these reports and portended a multiagency endeavor: the recommendations were made to several concerned agencies—to the National Oceanic and Atmospheric Administration (NOAA) and the National Science Foundation (NSF)—in addition to the sponsoring agency, NASA.
Late 1986 brought the beginnings of a coordinated government response. NASA, NOAA, and NSF had been developing parallel global change programs, but in 1987 a joint letter from the three agencies to the director of the Office of Management and Budget (OMB) proposed the idea of a budget presentation coordinated across the agencies. From this point on, OMB was instrumental in developing the USGCRP. Later that year a consortium of eight agencies formed the federal interagency Committee on Earth Sciences (later the Committee on Earth and Environmental Sciences, now the Committee on Environment and Natural Resources). The first funding for the USGCRP per se came in fiscal year 1989, and the first related descriptive document that accompanied the president 's budget was produced for the fiscal year 1990 submission. Joint submission of agency budgets was a novel concept, at least in the Earth sciences. The process produced new initiatives that were coordinated if not necessarily integrated. Thus, the USGCRP was initiated and first presented in the federal budget by President Reagan, was codified into law in 1990 (see Appendix A), and was implemented by President Bush; today it is being carried forward under President Clinton.
Scientific Roots of Global Climate Research
The intellectual crucible in which the USGCRP was formed, however, was itself forged far earlier. The possibility of global changes in the biological, physical, and chemical environment had been recognized in the nineteenth century and became a widely accepted idea by the beginning of the twentieth century. In 1957, Revelle and Suess10 pointed out that most of the carbon dioxide emitted from fossil fuel combustion would remain in the atmosphere for many years and
drew on emerging climate modeling capabilities to suggest possibly alarming impacts on climate. In the early 1960s two major international conferences, known by the acronyms SMIC and SCEP,11 put the issue on the international agenda. At the same time, convincing observational evidence emerged that human activities were in fact changing the chemical composition of the global atmosphere. Measurements first taken by Charles David Keeling in 1957 revealed that carbon dioxide was indeed increasing in the atmosphere at the planetary scale. In 1964 the President's Science Advisory Council brought the issue to the attention of the U.S. government. Subsequently, beginning in the late 1960s, early computer model simulations started to explore the possible changes in temperature and precipitation that could occur from increasing human-induced emissions of greenhouse gases into the atmosphere.
During the 1970s and early 1980s, an important set of environmental topics was closely considered by the National Academy of Sciences (NAS). Foremost among these issues were potential changes in climate and losses in stratospheric ozone. The NAS convened several panels and committees under leading scientists such as the late Roger Revelle 12 and Jule Charney.13 The resulting reports projected that energy production from fossil fuels would continue to increase atmospheric concentrations of carbon dioxide and estimated that a doubling of the atmosphere's carbon dioxide concentration could potentially raise global average temperature by 1.5 to 4.5°C (about 2.7 to 8°F) and produce a complex pattern of worldwide climate changes. Charney and his colleagues concluded that if carbon dioxide continued to increase there was “no reason to doubt that climate changes would result and no reason to believe that these changes would be negligible.”14 The Revelle group saw a clear need for two kinds of action in response: “organization of a comprehensive worldwide research program and new institutional arrangements.” In the same period, ecologists also recognized that massive changes in ecosystems caused by land-use changes and other stresses could affect the carbon cycle. In this juncture of scientific findings, then, are the beginnings of the partnerships among the life and Earth sciences that have become the hallmark of global change science.
Still other studies addressed a widening range of potential global change impacts and their policy implications.15 In 1979 and 1989 major World Climate Conferences16 were convened by the World Meteorological Organization and other international bodies. International meetings17 converged on the conclusion that the implications of changing climate should be assessed for development policy. In 1988 the Intergovernmental Panel on Climate Change, composed of hundreds of scientists from more than 50 countries, assumed responsibility for conducting periodic international assessments on climate change and its onsequences. The latest of these18 affirms the validity of scientific concerns and concludes that human influences on climate are becoming discernible.
Thus, throughout the past two decades the NAS/NRC and their international counterparts have continued to examine the science of climate change and vari-
ability and the associated policy implications for the United States and other nations. Additionally, the NAS/NRC have simultaneously considered climate change and variability within the broader context of global change. The CGCR, author of this report, and CGCR's predecessor, the Board on Global Change, have been charged with providing continuing guidance to national and international global change efforts. In 1995, CGCR undertook an initial assessment of the scientific programs of the USGCRP, reviewed the specific role of NASA's Mission to Planet Earth/Earth Observing System, and issued a report with recommendations (the “La Jolla” report)19 and a follow-up report on the government response.20 The present study significantly expands that effort.
Scientific Roots of Stratospheric Ozone Research
A related history of research concerns another pressing environmental issue—depletion of the stratospheric ozone layer that shields us from damaging ultraviolet radiation. In the early 1970s, proposals to build a fleet of supersonic transports raised questions about possible damage to the ozone layer from engine emissions in the stratosphere. A major U.S. research and assessment program was launched, and the NRC was commissioned to conduct a series of studies.21 But soon Rowland and Molinaa made the startling discovery that chlorofluorocarbons (CFCs), not airplanes, were the frightening threat to our ozone shield. Eventually, an international assessment was conducted under the auspices of the World Meteorological Organization and other international bodies. 22
The discovery by Rowland and Molina reminds us that studies and reports often do not adequately address the complexities of the real world. Indeed, they can even significantly miss the mark. Studies of ozone depletion had focused on slow incremental changes and had sought incremental improvements through corresponding models and parametric analyses. Meanwhile, observations extending back to the 1950s had been tracking the amount of ozone over the Antarctic each year through its seasonal cycle. In the late 1970s an anomalous deficit was observed in the total amount of ozone over the southern hemisphere in late winter observations. Then in 1985 the British Antarctic Survey reported dramatic—and rapidly worsening—ozone losses in springtime ozone concentrations over Halley Bay.
Theories about the cause of this unprecedented and unexpected loss blossomed. Explanations ranged from the hypothesis of the simple redistribution of stratospheric ozone by atmospheric motion to proposed chemical reactions initi-
The Swedish Academy of Sciences awarded the 1995 Nobel Prize in Chemistry to F. Sherwood Rowland, Mario Molina, and Paul Crutzen for their work in atmospheric chemistry. Rowland and Molina published an article in Nature in 1974 that showed that CFC releases into the atmosphere cause stratospheric ozone depletion. Paul Crutzen had previously shown the importance of nitrogen oxide catalytic chain reactions in controlling the amounts of stratospheric ozone.
ated by the magnetic field focusing of solar electrons and protons. More complete information was clearly needed. In 1986, NASA began planning an airborne expedition using the ER-2 aircraft to penetrate the region of the stratosphere where ozone was disappearing. The mission, executed in August and September 1987 from Punta Arenas, Chile, demonstrated that ozone was being destroyed by chlorine and bromine radicals. The role of CFCs—molecules that transport chlorine to the stratosphere—in the destruction of Antarctic ozone was unequivocally confirmed. Shortly thereafter, laboratory and theoretical work pinned down other essential mechanisms of the process—mechanisms involving cloud particles, which had been overlooked in earlier studies.
With such overwhelming evidence in hand, the nations of the world moved with remarkable alacrity to mitigate the threat. International meetings developed strategies to control emissions of ozone-destroying substances, while the chemical industry worked to devise substitutes for CFCs. Within a few short years a comprehensive framework for controlling worldwide emissions had been put in place in the form of the justly admired Montreal Protocol.23
A number of lessons relevant to the broader field of global change research may be drawn from the case of research on Antarctic ozone depletion. The severity of the ozone phenomenon demonstrates that environmental changes are not always incremental or slight. Moreover, the severity of ozone loss came as a total surprise, even though the topic had been carefully considered by the scientific community. Finally, however, the problem was assessed in remarkably short order and effective remedial measures were rapidly instituted—because a solid base of related scientific understanding had been developed through decades of focused observation and research.
An additional critical point to make in this context is that many issues in global environmental change, such as climate change, are far more complex than even the difficult ozone story. The chemical, physical, and biological aspects of the greenhouse problem are extraordinarily daunting to study, and yet an additional and more difficult challenge probably lies in understanding the human dimensions of global change phenomena.
THE ROAD AHEAD
What surprises are in store in the future? By definition, surprises cannot be fully anticipated; at best they can be acknowledged as possibilities. As such they pose a special challenge to science. Science must formulate specific questions to set about obtaining the critical observations and performing the analyses needed to answer them. It is hard to ask questions that will anticipate all possible surprises before a surprise occurs.
Preparing science for surprise is, in part, the challenge that the CGCR faced in developing this report. Scientists believe strongly that unfocused research on the complex and varied Earth system is unlikely to be productive. On the other
hand, scientists who view the world through pinholes are likely to bump into trees and fall off cliffs. How can needed focus be given to the USGCRP while still casting the research net sufficiently wide to catch the unexpected? In this report the CGCR has sought to define a framework for this endeavor, identifying a set of coherent domains of research that are likely to provide efficient and productive progress for science and to encompass the range of scientific and social issues implicit in global environmental change. This framework builds on the initial set of guiding principles defined by the committee in its La Jolla report and on the issues of great scientific and practical importance in mature areas of Earth system science that are identified in this report.
THE PATHWAYS FRAMEWORK
This report outlines a research framework across the wide scope of global environmental change in terms of the following primary topical areas:
changes in the biology and biogeochemistry of ecosystems,
changes in the climate system on seasonal-to-interannual timescales,
changes in the climate system on decadal-to-century timescales,
changes in the chemistry of the atmosphere,
human dimensions of global environmental change.
Pathways begins with biology and biogeochemistry because of our intimate dependence on biological systems, because of the sensitivity of these systems to changes in the physical and chemical environments, and because of the pivotal role of biology in the changing biogeochemical cycles of the planet. These biogeochemical cycles are, in a sense, the metabolic chart for the planet; they provide particularly useful benchmarks of global change.
We look next into the climate system, focusing initially on climate variability on seasonal to interannual timescales and then on climate change on decadal-to-century timescales. We find that we also must consider climate variability and change on the intermediate timescale of a human generation.
Changes in the chemistry of the atmosphere drive many global changes; the atmosphere quickly transports chemical inputs from whatever source, and the chemical loadings are of sufficient scale that they can no longer be ignored. Testing ideas about global change on longer timescales is not like research to improve weather forecasts, in which feedback and correction are almost immediate. The paleoclimate record offers a unique opportunity to assess ideas about the dynamics and causes of global environmental change and variability. This record also tells us that large departures from simple expectations have occurred in the past, forcing the recognition that any program addressing global change must be
sufficiently broad in scope to ensure that surprises are caught early. This consideration is particularly important for devising observational strategies.
The human dimensions of global environmental change—that is, humans and their institutions as both agents and recipients of change—are integrated where possible into the other topical chapters of this report and are also the subject of a separate treatment. Many concerns about the changing environment are tied directly to concerns about human and ecosystem health and welfare.
The discussion of each of the six primary topical areas is structured in terms of Research Imperatives—central issues posed to the corresponding scientific community by the challenge of global environmental change. Four to six Research Imperatives are identified for each topical area. Sometimes these imperatives closely interconnect. The Research Imperatives provide guideposts for the research “pathway.”
Each Research Imperative is addressed by a set of Scientific Questions. The limbs of the research strategy begin to branch and spread. If surprises are in the wind, we hope that this broadly spreading canopy of topics, Research Imperatives, and Scientific Questions will catch the signal.
The Scientific Questions are posed at a level of detail from which an observational program, space-based and in situ, can be defined, refined, and realized. The observational strategy also consciously recognizes that surprises might well be in store. For this and other scientific reasons, an essential requirement of the observational strategy is to establish long-term, scientifically valid, consistent records for global change studies. It is fortunate that the paleoclimate community has provided extremely detailed histories of climate and environmental change that can underpin the instrumental records, establishing some basis for the assessment of future monitoring. Long-term monitoring is a central scientific challenge for global change research. It is also a difficult challenge to meet in a social environment that so often values or wants something new.
Observations are essential to test hypotheses from which models can be developed. Models are essential if prediction and synthesis are sought. Observations are useless, however, if the data are inaccessible to users (e.g., because of the problem of data recorded in “write-only ” memory). Data systems have been a constant challenge to all scientific investigations; they are particularly problematic when large amounts of data are involved, as in global change studies. Fortunately, through a unique confluence of satellite and computer technology, science stands on the threshold of a greatly enhanced ability to exploit such masses of data and hence is well positioned to monitor and predict changes in the global climate and environment. Satellites orbiting the Earth can monitor changes in sea height, wind velocity, atmospheric water vapor, snow cover, and a wide variety of other parameters. Satellite data can be merged with ground-based measurement networks in a matter of minutes through a series of telecommunications satellites, microwave links, and fiber. Data derived from these sources serve as
inputs to large computer-based models, which in turn provide predictions about future environmental trends and variability. The existing and future Internet and associated services give the USGCRP an opportunity to manage this stream of data successfully and at reasonable cost.
A data strategy is needed that emphasizes flexible and innovative ystems—systems that are less costly than the current EOS core system, that appropriately reflect focused responsibility for data character, that provide open access to the scientific community and the public, and that rapidly track technological developments.
REVIEW OF THE USGCRP
As mandated in the legislation establishing the USGCRP (see Appendix A), the NRC has provided continuing oversight and review of the program (see References). Oversight has been the responsibility of a consortium of NRC groups, coordinated through the former Board on Global Change (now the Board on Sustainable Development and its Committee on Global Change Research, CGCR) and other predecessors. For example, the Climate Research Committee and its panels (operating under the NRC's Board on Atmospheric Sciences and Climate) have overseen climate-related elements of the USGCRP, with particular attention to international programs such as the Tropical Ocean-Global Atmosphere (TOGA) program. The NRC's Committee on the Human Dimensions of Global Change has carried out seminal studies to define social science aspects of the USGCRP. The CGCR and other NRC units receive regular updates on program status at their meetings. With participation by these and other NRC boards, committees, and panels, the CGCR carried out a comprehensive review of the program in the summer of 1995,24 followed in 1996 by a review of government actions taken in response to the 1995 report.25 In November 1996 the approach to the Pathways report was determined at a CGCR meeting, which for the first time convened representatives from each of the USGCRP agencies and chairpersons and staff of each NRC committee involved in global change research. The findings and recommendations of the present report are based on this continuing stream of review and assessment.
The central purposes of the USGCRP areas are as follows:
to observe and document changes in the Earth system;
to understand why these changes are occurring;
to improve predictions of future global changes;
to analyze the environmental, socioeconomic, and health consequences of global change; and
to support state-of-the-science assessments of global environmental change issues.26
These “central purposes” of the USGCRP set a clear, appropriate, overarching vision for the Program. Moreover, during the past decade, the USGCRP has realized an impressive array of scientific accomplishments. Progress has been made in understanding the loss of stratospheric ozone, and amendments and adjustments to the Montreal Protocol have benefited from research flowing from the USGCRP. Ice cores have provided evidence of past changes in the Earth's environment, and human-induced environmental changes have been documented. There is a much better understanding, including the development of large-scale models, of the important roles of terrestrial and marine ecosystems in the overall carbon cycle, including knowledge of how such systems might shift under a changing climate. The success in providing predictive and useful information about El Niño-Southern Oscillation (ENSO) phenomena is a significant step in providing scientific information for natural resource management and for improving human welfare, and it offers encouragement that the broader issues of climate variability and human-induced climate change can also be successfully attacked. Finally, some accomplishments in observations are noteworthy. The precise measurements from space of sea surface height by the U.S.-French Topex-Poseidon mission have advanced our knowledge of sea surface change and ocean circulation. The Mission to Planet Earth Pathfinder datasets have advanced our insights across a wide array of global change issues.
The inherent challenges in achieving the central purposes of the USGCRP, however, will be ongoing; to ensure our well-being for the foreseeable future, it is essential to meet these challenges. They also set a formidable and difficult agenda for science, and this conclusion carries with it the need to do better. We must find ways of advancing the scientific attack on the problems of global environmental change more effectively. Fortunately, with 10 years of experience of successes and setbacks, we are in a far better position to meet the scientific challenges in the coming decade. There is, in fact, a rich body of information, in the form of lessons learned, to be gleaned from the past decade.
What are the lessons of the past 10 years? The reviews carried out over the Program's first decade have in fact identified a key set of “lessons learned”—attributes that the Program must maintain and precepts it must observe to achieve greater and needed successes in attacking the difficult issues of global environmental change.
Need for Programmatic Focus
Where research communities have been given resources based on collaboratively established priorities to implement critical activities, maintain and distribute datasets, and synthesize the information, rapid and impressive progress
has been made. Such successes have occurred primarily within the framework of formal programs (e.g., the TOGA studies of El Niño and the Upper Atmosphere Research Program studies of ozone destruction that led to the Montreal Protocol) and sometimes through grassroots initiatives (e.g., carbon cycle modeling). Many global change projects are currently on a positive trajectory and success is likely. However, many critical global change questions are not receiving the level of support needed to make similar progress; the sum of support for the current “focused”b programs, according to the USGCRP specifications, represents an inadequate fraction of what is needed to accomplish its goals. For example, of the total fiscal year 1998 budget request for the USGCRP, 61 percent supports space-based observation programs and 39 percent supports scientific research.27
In part this problem has arisen because of disaggregation of the national effort across multiple agencies. The agencies have neither an enforceable mandate to cooperate in a manner necessary to be successful nor a system that requires accountability of expenditures. The Committee on Environment and Natural Resources (CENR) of the National Science and Technology Council (NSTC) was designed to improve the coordination of both the USGCRP agencies and the budget crosscuts with OMB in presenting a national program. Unfortunately, the management framework has not had the expected effect. The desired “virtual agency”c has been quite far from reality.
The fact that a principal componentd of the nation's global ocean-carbon cycle research program fell victim to budget reductions during 1996 to 1997 at DOE and required a last-ditch ad hoc rescue by NOAA is a clear statement of programmatic failure, not programmatic success. The tradeoffs between carbon sources and sinks were considered issues of immense economic significance in the recent Kyoto climate negotiations. Better understanding of the carbon cycle will be of great value in the ongoing negotiations. On the positive side, there are new and encouraging signs of focus and priority emerging from the NSTC/CENR structure and process.
Need for Program Balance
It can also be argued that there is currently an imbalance within the program among its major components: observing systems, data systems, and research and
A “focused” program is defined by the USGCRP as an agency program that was created specifically to address the stated goals of the USGCRP. The total USGCRP “focused” budget is the sum of the “focused” agency programs. At one time the USGCRP also designated “contributing” programs that “provide important support to the program objectives but were initiated for reasons other than the focused Program goal” (FY 1992, Our Changing Planet).
“Virtual agency” refers to the USGCRP interagency body. See USGCRP (1997, p.ii).
The planned data analysis component of the program.
“. . . the following set of fundamental principles . . . should guide the development and implementation of the US Global Change Research Program in the future:
analysis. For instance, in the fiscal year 1996 USGCRP budget breakout, Our Changing Planet,28 of the $1.83 billion allotted to the global change program, $1.19 billion (65 percent) was allocated to “Observing the Earth System ” ($845 million) and “Managing and Archiving Data and Information” ($343 million). Of the remainder, $434 million was allocated to “Understanding Global Change” (24 percent). As indicated above, this distribution of resources essentially continued in the fiscal year 1998 budget. It can be argued that the large investment required to develop and deploy the space observation component of the USGCRP has comprised perhaps too large a fraction of the program's “focused” budget. Nevertheless, the space missions designed to facilitate global change research, such as sea surface altimetry and scatterometry and the Upper Atmosphere Research Satellite, have been great successes. Moreover, after an 11-year hiatus, the capability to obtain ocean color data has recently been restored with great scientific reward.
NASA's Earth Observing System (EOS) polar platforms—EOS AM-1, EOS PM-1, and EOS CHEM-1—were conceived as broadly scoped data-gathering systems. This foundation will be central for needed future missions and will set the baseline for a long-term operational environmental monitoring program that must be built on the operational weather and ozone-observing system of NOAA, the U.S. Department of Defense (DOD), and their international partners. However, while the EOS should begin to pay dividends with the scheduled 1998 launch of the AM-1 observatory followed by the late 2000 launch of the PM-1 mission, the initial focus of the USGCRP on EOS set a near-term timescale (and a cost) that made rapid response to scientific and technical challenges difficult.
The question of balance is further complicated by the realities of federal funding. Savings that might be obtained by trimming costs at NASA from space-based observations would be unlikely to flow within the agency to in situ observational activities, let alone to the research and analysis (R&A) component (or even to other space-based missions). Still more unlikely is the transfer of such funds to other agencies within the USGCRP. These are political and institutional realities. Nevertheless, there remains the question of balance within the overall
USGCRP observational system between space-based and in situ systems. (In fiscal year 1996 only 11 percent of USGCRP observations were devoted to in situ measurements.) Finally, although major breakthroughs have emerged from the R&A component of the national effort, it is just this part of the effort that continues to receive serious cuts within several agencies in the USGCRP.
Several lessons about Program balance can thus be extracted from the past 10 years. First, space-based observations are essential yet costly. We need to find ways to lower their cost while also making the space-based systems more budgetarily robust and flexible. We applaud NASA's Earth System Science Pathfinders and its rethinking of the EOS mission structure as steps in the right direction. Still another lesson is that in situ observations are critical (e.g., the TOGA ocean buoy array for ENSO prediction); yet in situ observational systems such as radiosonde and ozone networks continue to degrade around the world. We need to find ways to implement new in situ observing systems while restoring and maintaining key existing systems. Finally, in recent years the scientific community has gone through a difficult experience: R&A budgets in critical areas have continued to decline, and science is simultaneously being asked for answers to increasingly difficult and important questions. We must find ways to reverse this declining trend (NSF's proposed fiscal year 1999 budget is a welcome change).
Need to Maintain Critical Observations
During the past 10 years, the value of critical combinations of models and observations has been repeatedly demonstrated in providing the nation and the world with critical information about specific issues of global environmental change. The observing system that proved so valuable in the early detection of the 1997 to 1998 El Niño is a case in point. The research-based observing system and coupled atmosphere-ocean models developed under the auspices of the TOGA program to study ENSO phenomena made it possible as early as spring 1997 to detect and predict the 1997 to 1998 El Niño and its potential magnitude. Many social and economic systems are profoundly affected by weather events and climate patterns linked to ENSO; people in locations as distant as central Africa, southeast Asia, Australia, and North America are all benefiting from this scientific work, as agricultural, flood management, relief assistance, and market practices are adjusted.
Establishing an operational capability to maintain this initial ENSO observing system and training practitioners in the use of the data are large challenges, but there can no longer be any doubt that the investment has brought results of scientific interest as well as practical concern for natural resource management. This is an example of a crucial tenet of the Earth System Sciences Committee's strategy for studying global change: the institutionalization of critical measurement systems in an operational mode once their efficacy in documenting information valuable to policy makers is demonstrated in the course of a research
program. This requirement will continue to be challenging for ENSO research, but more broadly the past 10 years have shown clearly that correctly transferring other key aspects of the observing program for USGCRP to operational programs will be very difficult.
This lesson also emerges clearly from negotiations on the polar platforms of NASA, NOAA, and DOD over the past 10 years. To date, the process is not a story of success for the USGCRP. For example, regarding coordination of the next generation of NOAA/DOD operational polar platforms and NASA EOS AM-1 and PM-1 satellites, if current plans proceed, there will be a significant gap between the conclusion of the flight of EOS PM-1 and the first NPOESS-1 (nominally planned for an afternoon crossing).e This gap will be significant because it will make coordination and calibration of the measurements taken by EOS PM-1 and NPOESS-1 extremely difficult.f Beyond this specific issue and the continuing problem of adequately sequencing observations, there is a more general lesson to be learned: it is difficult for an operational program (e.g., NPOESS) to incorporate an adequate level of scientific advice, review, and essential oversight to ensure that the scientific needs of global change science will be addressed. This difficulty has been exacerbated until quite recently by NASA's distance from the NPOESS planning process; moreover, NPOESS itself is driven by two operational agencies (NOAA and DOD) with somewhat different demands on the data and data calibration and accuracy requirements, and it is understandable (but problematic) that global change issues are not high on the priority list.
The connectivity between EOS AM-1 and the future midmorning operational polar platform, EUMETSAT's METOP-2/3, is even more confused. This general issue brings to mind the additional difficulty of ensuring adequate coordination internationally, as possibilities are explored to transfer scientifically motivated observations to operational programs.
Other examples of problems are beginning to arise as research programs dependent on global observations of ocean, land surface, and atmospheric properties are concluding their intensive field campaigns. No provision is in place to make the necessary commitments for systematic acquisition of operational climate and global change in situ data to continue the key time series started by these programs. These are precisely the types of problems that the USGCRP was charged to resolve.
Need for Well-Calibrated Observations
During the past 10 years, we have been reminded again and again of the painful consequences of attempting to use inadequately calibrated observations
The next generation of weather satellites is referred to as the National Polar-Orbiting Operational Environmental Satellite System (NPOESS).
This is discussed further in Chapter 8.
to answer important questions about global environmental change. On a more positive note, great scientific advancements have been made when it is possible to use long-term, highly calibrated, rigorously maintained scientific observations. For example, precise measurements of atmospheric concentrations of carbon dioxide have yielded valuable information about the annual cycle of the biosphere and the distribution of carbon dioxide sources and sinks. Precise measurements of CFCs have also enabled the tracing of atmospheric and oceanic circulations and improved our understanding of stratospheric ozone loss. Precise measurements of solar radiance have helped us distinguish between natural and human influences on global mean temperature. The general lesson here, then, is that high-quality data are an immensely powerful lever to obtain scientific insights on global change.
Need for a Focused Scientific Strategy
The NRC's reviews of the USGCRP over the past decade (see References), notably the intensive community-based review conducted at La Jolla in the summer of 1995,29 have consistently emphasized the need for the program to focus on critical scientific issues and the unresolved questions that are most relevant to pressing national policy issues. This document strongly reiterates that view. The nation and the world are beginning to make momentous decisions about development, technology, and the environment; at the same time, economic and political factors place severe constraints on budgets for research and infrastructure. A sharp focus on the truly essential investments in research and supporting infrastructure is thus more important than ever. A more sharply focused scientific strategy for the USGCRP is urgently required.
Charting and understanding the course of change in the Earth's physical, chemical, and biological systems, and their connections with human activities, are fundamental to the nation's welfare in the coming decades. Economic decisions, international negotiations, preservation of public health, and educational development demand this understanding. For example, without trusted knowledge about changes in the carbon and hydrological cycles, ecological systems, temperature structure, storm systems, ultraviolet intensity, nutrient deposition, and oxidant patterns, defensible positions for international measures to protect the environment cannot be established and sustained.
Development of this urgently required knowledge will demand concerted efforts and continuing scientific leadership. As the world's leading scientific nation, the United States, working with the international community, must recognize the importance of providing scientific leadership in defining and diagnosing changes in the state of the Earth system in the context of national needs and scientific interests. Strategic decisions on scientific goals, research programs, and supporting infrastructure are critical elements of this leadership, and it is the committee's view that a new strategic approach is needed. We thus present our findings and recom-
mendations here with the full sense of responsibility that accompanies the strong belief that the challenges posed to people by global environmental change will not go away. The challenges will not be legislated out of existence; they will be faced by our children's children, and they must be faced by us.
1. WMO (1979).
2. DOE (1977, 1980).
3. Goody (1982).
4. NRC (1966), Fein et al. (1983).
5. There have been dozens of NRC reports addressing this topic; the References contain many examples.
6. ESSC (1986, 1988).
7. Goody (1982).
8. NRC (1986).
9. ESSC (1986, 1988).
10. Revelle and Suess (1957).
11. MIT (1970, 1971).
12. NRC (1982a).
13. NRC (1979).
15. NRC (1982b, 1991).
16. WMO (1979, 1990).
17. WMO (1984, 1986).
18. IPCC (1995).
19. NRC (1995).
20. NRC (1996).
21. For example, NRC (1982c).
22. A recent update is contained in UNEP (1994).
23. Montreal Protocol to the Vienna Convention on Substances that Deplete the Ozone Layer (1987).
24. NRC (1995).
25. NRC (1996).
26. USGCRP (1997, p. 3).
27. Ibid., p. 78.
28. USGCRP (1995, p. 109).
29. NRC (1995).
REFERENCES AND BIBLIOGRAPHY
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Earth System Sciences Committee (ESSC). 1986. Earth System Science. Overview.Advisory Council, National Aeronautics and Space Administration, Washington, D.C.
Earth System Sciences Committee (ESSC). 1988. Earth System Science. A Closer View. Advisory Council, National Aeronautics and Space Administration, Washington, D.C.
Fein, J.S., P.L. Stephens, and K.S. Loughran. 1983. The Global Atmospheric Research Program: 1979-1982. Reviews of Geophysical and Space Physics 21:1076-1096.
Intergovernmental Panel on Climate Change (IPCC). 1995. Climate Change 1995: IPCC Second Assessment ReportCambridge University Press, Cambridge, Mass.
International Council of Scientific Unions (ICSU). 1996. Understanding Our Planet.ICSU Press, Paris, France.
Massachusetts Institute of Technology (MIT). 1970. Man's Impact on the Global Environment. Report of the Study of Critical Environmental Problems (SCEP).MIT Press, Cambridge, Mass.
Massachusetts Institute of Technology (MIT). 1971. Inadvertent Climate Modification. Report of the Study of Man's Impact on Climate (SMIC).MIT Press, Cambridge, Mass.
National Research Council (NRC), Committee on Atmospheric Sciences. 1966. The Feasibility of a Global Observation and Analysis Experiment. National Academy Press, Washington, D.C.
National Research Council (NRC), Ad Hoc Study Group on Carbon Dioxide and Climate. 1979. Carbon Dioxide and Climate: A Scientific Assessment.National Academy Press, Washington, D.C.
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National Research Council (NRC), CO2/Climate Review Panel. 1982b. Carbon Dioxide and Climate: A Second Assessment.National Academy Press, Washington, D.C.
National Research Council (NRC), Board on Environmental Studies and Toxicology. 1982c. Causes and Effects of Stratospheric Ozone Reduction: An Update.National Academy Press, Washington, D.C.
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National Research Council (NRC), Committee on Global Change Research. 1996. A Review of the U.S. Global Change Research Program. Letter report. National Research Council, Washington, D.C.
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United Nations Environment Program (UNEP). 1994. Scientific Assessment of Ozone Depletion 1994.United Nations Environment Program, Geneva.
U.S. Department of Energy (DOE). 1977. Workshop on the Global Effects of Carbon Dioxide from Fossil Fuel, W. P. Elliot and L. Machta, eds. DOE, Washington, D.C.
U.S. Department of Energy (DOE), 1980. Workshop on Environmental and Societal Consequences of a Possible CO2-Induced Climate Change. Conducted by the American Association for the Advancement of Science, April 2-6, 1979, Annapolis, Md. DOE, Washington, D.C.
USGCRP. 1992. Our Changing Planet: The FY 1993 U.S. Global Change Research Program A Supplement to the President's Fiscal Year 1993 Budget. U.S. Global Change Research Program Office, Washington, D.C.
USGCRP. 1995. Our Changing Planet: The FY 1996 U.S. Global Change Research Program A Supplement to the President's Fiscal Year 1996 Budget. U.S. Global Change Research Program Office, Washington, D.C.
USGCRP. 1997. Our Changing Planet: The FY 1998 U.S. Global Change Research Program A Supplement to the President's Fiscal Year 1998 Budget. U.S. Global Change Research Program Office, Washington, D.C.
World Meteorological Organization (WMO). 1979. Proceedings of the World Climate Conference.WMO, Geneva.
World Meteorological Organization (WMO). 1984. Report of the Study Conference on Sensitivity of Ecosystems and Society to Climate Change. WMO Publication 83. WMO, Geneva.
World Meteorological Organization (WMO). 1986. Report of the International Conference on the Assessment of the Role of Carbon Dioxide and of Other Greenhouse Gases in Climate Variations and Associated Impacts.WMO, Geneva.
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