The atmospheric, oceanic, and terrestrial systems interact with one another and with organisms in complex ways to produce the richly varied environment that supports all life, including our own. Until recently, scientific studies have concentrated primarily on processes in each of these sectors separately because of the need to understand simpler pieces before tackling the larger system.
Much is known about the earth and its space environment as a result of investigations extending over centuries. We know about the general magnitude and quality of changes in the physical environment that have occurred over the history of the planet, and we can make some projections about what might happen in the future. But our knowledge is still sparse. Although we are beginning to have some success in predicting large-scale phenomena, such as El Niño, many months in advance, we can predict local weather patterns with useful accuracy only a few days in advance. We still know little about how the oceans work–how their chemical, biological, and physical processes interact. Vast areas of the oceans remain unmeasured in any systematic way, and we have little idea of the long-term variability of marine systems. We have good observations of the surface geology of the earth, but we have only a few samples from below the surface, most of them from shallow depths. Our knowledge of the interior of the earth comes almost exclusively from indirect measurements.
New insights from research and new technology, such as accurate chemical techniques and satellite imagery, supported by powerful computers, have given us the ability to view the earth with greater comprehension. During the last two decades, the atmospheric, oceanic, and geophysical communities have developed coordinated global research programs that use the new insights and technology that are now available. Examples of such programs are the International Geophysical Year (1957-1958), the International Ocean Drilling Program (begun in 1968), the Global Atmospheric Research Program (begun in 1979), and the World Climate Research Program and International Geosphere-Biosphere Program (begun in the 1980s) (Fleagle, 1992).
The federal government has provided considerable support for research on the physical and chemical components of the global system, but good ideas