The Earth photographed from a distance of 40,300 km by the crew of the Apollo 17 mission on their way to the Moon (December 1972)
Introduction
The latter half of the 20th century has revolutionized man's perspective of planet Earth by providing a view of our home planet from space. Indeed, Apollo VIII astronauts were the first to observe the Earth rising over the horizon from a celestial body (i.e., the moon) other than Earth itself. Observing the Earth silhouetted against the black backdrop of space, one can hardly deny its wholeness and fragility. Earth System Science was born out of the Space Age and is a holistic approach to studying the Earth as a system of interacting components. Just as human physiology can be viewed as a system of interacting components (nervous, pulmonary, circulatory, endocrine systems, etc), so too can the Earth be understood as a system of four principal components (atmosphere, biosphere, geosphere, and hydrosphere). In fact, James Hutton, often considered to be the father of modern geology, suggested that the proper study of the Earth should be by "geophysiology". This view has been expounded on by James Lovelock and Lynn Margulis in the GAIA hypothesis.
The four components of the Earth system interact with one another by flow of matter and energy among the reservoirs. For example, the biosphere and atmosphere exchange mass when plants photosynthesize withdrawing carbon dioxide gas from the atmosphere and producing oxygen gas as a byproduct. In turn, atmospheric gases are exchanged with dissolved gases in the oceans (hydrosphere). The roots of plants are involved in the break down (weathering) of solid rock (geosphere) to form soil. The human species (also known as the anthrosphere) has increased its population and technology to the point where we are no longer a passive part of the Earth system. Rather, we have begun to modify the other components of the earth system by our industrial and agricultural practices. In order to fully understand the complex issues of global environmental change that challenge society today (e.g., greenhouse warming, ozone depletion, deforestation, acid rain, desertification, biodiversity, etc), we must learn how to view the Earth as a system and identify the complex linkages and feedback processes that exist among its components. We welcome you to explore this WWW site and develop a system's perspective of the planet Earth.
The Introduction to Earth System Science at the University of Florida gives a historical description of this program and describes additional courses offered in Earth and environmental studies.
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Copyright © 1996,
2000
Dr. David Hodell and Ray G. Thomas.
All Rights Reserved Worldwide.