Looking at the Global System

Charles Hosler
December 01, 1984

The entire earth—land, ocean, atmosphere, and biosphere—is a dynamic and interactive system. The parts of the system have been studied, but when we are dealing with acid rain, the red tide, forest growth, groundwater contamination, the depletion of stratospheric ozone, or the greenhouse effect, the interconnected nature of earth, water, and air demands a more holistic approach than has yet been attempted.

We humans have reached the point where we can alter the environment on a global scale—with implications for food production, the quality of water and air, and the integrity of global chemical cycles that are essential to life. As we recognize isolated problems related to our alterations of the globe, we also recognize our ignorance of the total workings of the system. The problems that have surfaced are only the precursors of dozens of others that will emerge out of the murky understanding we now possess. We must address these problems as they emerge, and anticipate others that we might avoid.

Look, for example, at the greenhouse effect. There is no doubt that when we clear the forests, burn the wood, and burn millions of tons of fossil fuels, we increase the amount of carbon dioxide in the atmosphere. This has gone on for thousands of years; carbon dioxide has increased 5 percent in the last 20 years.

There is also no doubt that carbon dioxide traps heat in the atmosphere, as do glass panes in a greenhouse. But the net impact of the CO2 increases caused by man is still somewhat in doubt. The ocean absorbs and releases CO2 . Plants and bacteria use it, decay produces it, hot spots on the sea floor cause carbonates to precipitate and settle on the bottom. In addition, the atmosphere's response to warming at the surface is complex, and consequences of warming, such as more cloudiness or heavier snow over the continents, may reflect solar energy back to space and cancel out the warming. Thus, biological, geochemical, and meteorological questions must be answered in order to predict the consequences of CO2 increase with respect to weather, climate, and plant growth.

Meanwhile, methane, nitrous oxide, ozone, and a number of other gases are present in very small amounts in the atmosphere. They currently have about 50 percent the heat-trapping effect of carbon dioxide. All of these gases are inexplicably increasing. If the increase continues, by 2010 they and CO2 will have equal impact on the heat balance of the atmosphere. The methane is primarily produced by ruminants (cows, goats, sheep), termites, rice paddies, and people. It has been increasing at a rate of 1 or 2 percent per year for over 100 years. Other gases are produced and exchanged with the atmosphere when eroded soil, leached nutrients, and chemical fertilizers reach the streams and oceans and biochemical changes take place. All are important factors in the global geochemistry involved in the greenhouse effect.

The global nature of these interactions requires complex global observations—often simultaneous observations at many different locations over long periods of time. Individuals and single nations do not have the resources to attempt such all-inclusive observations, nor, until now, have the tools been available to observe and measure, and at the same time process and interconnect the data.

Events have changed our need and our potential. We have powerful data transmission, processing, and storage systems not even dreamed of 50 years ago. Satellite systems can now measure a great number of variables on a global scale. We are more aware of the impact of natural and manmade changes in the earth system on the nature and quality of life on earth. And there are signs that the international community may soon be receptive to some global programs that will study the earth system as a whole.

No one person can hope to make progress on the frontiers of all the required fields, but some individuals are going to have to be conversant with them. They will have to be able to interpret the results of research and put them together to create an overall picture.

"Outlook" is dedicated to ideas, to stretching the imagination, to exploring trends. Comments or rebuttals are encouraged. Write the Editor, Research/Penn State, 312 Old Main, University Park, PA 16802. Charles L. Hosler, Ph.D., is dean of the College of Earth and Mineral Sciences. This essay grew out of a lecture he gave to graduate students in the School of Journalism.

Last Updated December 01, 1984