U.S. Geological Survey

U.S. Geological Survey
Open-File Report 02-349
Online only
Online version 1.0

Human Impact on the Planet: An Earth System Science Perspective and Ethical Considerations


Richard S. Williams, Jr.

The modern Earth Narrative, the scientific story of the 4.5 billion-year natural and human history of the Earth, has emerged from the solid foundation of two factual concepts: Deep (or Geologic) Time and Biological Evolution. Widespread acceptance of the Earth Narrative is critically important as we begin the third millennium, because it provides a clear understanding of the growing impact of human population growth and associated activities on the Earth System, especially the negative impact on Earth's biosphere. It is important for humans to realize that we are but one of 4,500 species of mammals that exist on Earth and that we are but one species in the estimated 30 to 100 million species that form the complex biosphere. We also need to recognize that all species exist within the physical limits imposed by the geosphere. We are totally dependent on the biosphere for food, oxygen, and other necessities of life. Humans are one of the latest results of biological evolution operating over a long period of Geologic Time. We find ourselves on Earth, after 4.5 billion years of Earth history by chance, not by design. Humans have become so successful at modifying their environment that many of the natural limitations on the expansion of populations of our fellow animals have been overcome by technological and cultural innovations. According to Peter Raven "Humans, at a current population of 6 billion [expected to nearly double by 2050], are consuming or wasting about 50 percent of the total net biological productivity on land and 50 percent of the available supply of freshwater."

The overwhelming and expanding human presence leaves less and less room in the environment for other biota. The 21st century will be a pivotal time in the fate of Earth's biosphere. Whereas human modification of the geosphere will slowly recover over time, human changes to the biosphere are a far more consequential matter -- extinction of a species is forever! Will humans effectively use our new knowledge of natural and human history to stop further degradation of Earth's ecosystems and extinction of its biota? The fate of the biosphere, including humanity, depends on a reaffirmation by all humans of all cultures and religions of the global importance of a planet-wide conservation of the Earth's biotic heritage. For the world's religions it means elevation of stewardship of the Earth to a moral imperative and a goal of complete preservation of the Earth's biotic inheritance, one which is based on a Do No Harm ethic.

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This report is preliminary and has not been reviewed for conformity with U.S. Geological Survey editorial standards or with the North American Stratigraphic Code. Any use of trade, firm, or product names is for descriptive purposes only and does not imply endorsement by the U.S. Government

For questions about the content of this report, contact Richard S. Williams, Jr.

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