Below is the uncorrected machine-read text of this chapter, intended to provide our own search engines and external engines with highly rich, chapter-representative searchable text of each book. Because it is UNCORRECTED material, please consider the following text as a useful but insufficient proxy for the authoritative book pages.
Improving the capability to predict and respond to such changes, whether naturally-occuring or the result of man's activities, will provide a great benefit to our Nation. A well coordinated Federal global change research program will be critical to realizing these improvements. The U. S. Global Change Research Program Key Global Change Scientific Questions. A better predictive understanding of global change requires improved answers to the following four major questions that form the core of the U.S. Global Change Research Program research agenda: 1. What Forces Initiate Global Change? These forces include changes in solar irradiance, in the abundance of atmospheric trace gases and aerosols, in land use, in biota, and in the earth's orbit. 2. How Does the Earth System Respond to Changes in Forcing Functions? These responses or "feedbacks" include interactions among the climate, the ocean, the land, the biota, and the atmosphere. 3. How Has the Earth's Environment Changed in the Past? Differentiating between natural and human-induced global change requires clear documentation of the history of earth system variations over long time scales, especially prior to the influence of human activity. This documentation is provided by fossils, tree rings, pollen, soil composition, and sediments from the ocean, land, and ice. 4. How Well Can Global Change be Predicted? These evaluations include the ability of models to simulate past and present global changes and the biological responses to these changes.
Program Goal. Rational response strategies and sound policy can only be built upon reliable information, predictions, and assessments of the complex phenomena of the global earth system. It is in this context that the U.S. Global Change Re- search Program goal has been developed. U. S. Global Change Research Program Goal To Establish the Scientific Basis for National and International Policymaking Related to Natural and Human-induced Changes in the Global Earth System. The Program is based on the premise that three develop- ments have converged to make this goal feasible in the 1990's: 1. The science essential to an understanding of global change has matured dramatically in the past several decades and can begin to address the full range of global change research issues. 2. The methodologies and research tools to address the global scales of change are rapidly maturing and can be fully operational in the 1990's (e.g. earth-observing satellites, supercomputers for global scale models and for information management systems, advanced instru- mentation and measurement systems, and platforms for ground and ocean-based observations). 3. The national and international infrastructures and commitment to the global change research agenda are basically in place, with such elements as the Interna- tional Geosphere-Biosphere Programme, the World Climate Research Program, the CES, and the National Academy of Sciences.
10 Implementation Strategy. The U.S. Global Change Research Program's implementation strategy includes: (1) the identifica- tion of three major scientific objectives, (2) the integration of the various scientific disciplines, and (3) the integration of the Program with other national and international global change activities. (1) Three Major Scientific Objectives The U.S. Global Change Research Program has three parallel scientific objectives: monitoring, understanding, and predicting global change (see box on page 12 for further details). The aim of these objectives is to provide detailed assess- ments of the state of the knowledge of natural and human- induced changes in the global earth system. Appropriate predictions on time scales ranging from years to decades, in- cluding projections 20 to 40 years into the future, will be developed periodically. These assessments and predictions will provide information in such areas as: ecosystem dynamics, the biological influence on the climate system, concentrations of significant atmospheric constituents, oceanic and atmo- spheric circulation, and regionally useful information such as predicted changes in growing seasons, precipitation, and soil moisture. Assessments of uncertainties in these predictions will be an integral part of these predictions. (2) Integration of Scientific Disciplines The U.S. Global Change Research Program recognizes the need to achieve a greater level of integration among both single-disciplinary and multi-disciplinary scientific activities. The current foundation of earth science research rests primarily on single-disciplinary activities. However, such individual disciplines have limited capability to explain and predict global and regional scale interactive phenomena. Therefore, multi-
11 disciplinary programs are a necessary next step to improve the knowledge base and to obtain better predictive capability. Through these interdisciplinary studies, we have recognized the need for an even broader, more integrated view of the global earth system. The U.S. Global Change Research Program is the national effort to meet that need. It must simultaneously maintain and strengthen the foundation of single-discipline and multi-disci- pline science, the building blocks of an integrated understand- ing of the total earth system. To facilitate this integration process the Program focuses on the following seven interdisciplinary science elements: â¢ Biogeochemical Dynamics â¢ Ecological Systems and Dynamics â¢ Climate and Hydrologic System â¢ Human Interactions â¢ Earth System History â¢ Solid Earth Processes â¢ Solar Influences A more detailed discussion of these scientific elements is contained in Appendix B. The seven science elements were developed in close col- laboration with the National Academy of Sciences' Committee on Global Change, which is developing the U.S. component of the International Geosphere-Biosphere Programme. They are designed to maintain a broad and robust research capability, while focusing on those earth system processes and interactions most likely to lead to a practical predictive capability. As a result of this integrating process, each of the agency programs has become increasingly important to the overall success of the U.S. Global Change Research Program. continued on page 14
12 U. S. Global Change Res 1. Establish an Integrated, Comprehensive Monitoring Program for Earth System Measurements on a Global Scale There is no substitute for actual observation of global change. Observations not only provide direct indications of a changing world, but also serve to test models and predictions. Observations sometimes expose surprising phenomena. The Antarctic "ozone hole" and the rapid increase in atmospheric methane are examples. Knowledge of past global change is essential. Prehistoric changes are recorded in tree rings, sediments, glacier ice, and other parts of the natural record. Long-term records derived from frequent and well cali- brated global measurements of environmentally important parameters are critically needed. Global measurements from satellites and surface-based networks are crucial. 2. Conduct a Program of Focused Studies to Improve Our Understanding of the Physical, Chemical, and Biological Processes that Influence Earth System Changes and Trends on Global and Regional Scales Substantial progress has been made in understanding the sources, sinks, reservoirs, and fluxes of chemicals and energy through the earth system, but much remains to be learned. The earth systems seem to be capable of adjusting to change, particularly through "feedback" mechanisms. Some global processes tend to amplify change, while others tend to stabilize or oppose further change. Still other processes may respond minimally to changes in the system until a critical magnitude of change is reached, only to trigger and operate in a dramatically different mode. It has been suggested, for example, that ocean circulation may behave this way.
13 earch Program Objectives A number of key earth system processes are only beginning to be understood. Examples are: the exchange of heat and chemicals at the ocean-atmosphere interface, ocean circulation, atmospheric heating and cooling effects of clouds, the chemical and climatic effects of atmospheric gases and volcanic prod- ucts, the general chemical and physical influences on the atmosphere from land plants, and the underlying physiological responses of biological organisms. These processes are the building blocks of earth system models, and their definition requires sophisticated interdisciplinary studies. 3. Develop Integrated Conceptual and Predictive Earth System Models The rapidly expanding knowledge of earth system behavior permits the development of improved conceptual and computer- based models. The ultimate objective is to produce predictive models (e.g., climate change, environmental response, etc.) that will be useful at both global and regional scales and on many time scales. While scientific understanding is increasing, there remains much to do if truly integrated models of the earth system are to be developed. Many of the more serious uncertainties arise from limitations in computing capability and from gaps in our scientific understanding of important physical, chemical, and biological processes. Some of the most significant human impacts of global change are expected to be regional in scope, but current climate models cannot forecast at regional scales. Even with enhanced computing capability, scientists modeling the climate have found that the current characterization of the land and of plants to be inadequate for their models' needs and have called upon hydrologists and botanists to provide better descriptions of heat and water transfer.
14 (3) Integration with National and International Global Change Research Activities Both U. S. and foreign governments, collaborating closely with researchers at universities and in the private sector, have begun in the last few years to develop a cohesive approach to studying the global earth system. Examples of recent studies that focus on the study of the Earth as a single, integrated sys- tem include: â¢ "Earth System Science: A Program for Global Change" published in 1986 by the National Aeronautics and Space Administration's Earth System Sciences Committee; â¢ "Global Change in the Geosphere-Biosphere: Initial Priorities for an IGBP" published in 1986 by the National Academy of Sciences; and â¢ the International Council of Scientific Unions has orga- nized the International Geosphere-Biosphere Programme and recently published a plan of action. Building on these and related studies, the Program will develop national and international partnerships between gov- ernmental bodies, the academic science community, and the private research sector to achieve the specific objectives and long-term goals of the U. S. Global Change Research Program.
15 Major National and International Organizations Involved in Global Change Research Activities National Organizations â¢ FCCSET Committee on Earth Sciences â¢ National Climate Program â¢ National Academy of Sciences Committee on Global Change â¢ Other Boards and Committees of the National Academy of Sciences International Organizations â¢ International Council of Scientific Unions: Interna- tional Geosphere-Biosphere Programme and related activities â¢ World Meteorological Organization: World Climate Research Program and related activities â¢ United Nations Educational, Scientific, and Cultural Organization: Intergovernmental Oceanographic Commission and related activities â¢ United Nations Environmental Programme â¢ Intergovernmental Panel on Climate Change