Recent and historic concerns for environmental sustainability reflect the perceived linkages between the activities of human populations and the dynamics of the Earth’s systems and subsystems. Human effort has been calculated now to exceed the effects of natural forces in movement of materials on the Earth’s surface (Monastersky, 1995). Images of the Earth at night, as seen from space, clearly show the extent and concentrations of human habitation on the planet, and they document the conversion of unprecedented amounts of energy for human consumption. Much of the utilized energy is derived from fossil fuels, energy stored during a previous era by natural processes. Citing another study, Postel states that humans have “appropriated nearly 40 percent of the terrestrial food supply, leaving only 60 percent for the millions of other land-based plants and animals” (1994, p. 8). As we approach the 21st century, critical thinking must be directed toward these and other global environmental issues since our individual and collective choices influence future options. Are citizens aware of future prospects and are they adequately prepared for action on these issues?
