A Sweet Briar College Learning Resource

H2O - The Mystery, Art, and Science of Water

Professor Sang Hwang

Global Environmental Change

The earth is currently undergoing a dramatic level of change. Humans beings now have the capacity to modify earth's basic life support systems and alter the global geophysical processes which took millions of years to evolve in matter of decades. The dramatic changes in geophysical, social, cultural, and economic systems have provided higher levels of productivity, increasingly connected global communications, and higher levels of wealth to more developed, richer countries of the world. For much of the population on the planet, however, the changes have brought about increasing levels of poverty, ecological degradation, and cultural fragmentation.

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One of the most important life support systems on the planet is the hydrologic cycle. We are facing serious consequence for the current and future generations in the way we are contaminating our freshwater resource. A recent 1998-1999 Report on freshwater resources cite following disturbances in the current freshwater system.

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Photograph: © Jim Holmes

Feeling the Pulse of Water Resource Use

  • Per-capita water demands are increasing and per-capita water availability is declining due to population growth and trends in economic development.

  • Half the world's people lack basic sanitation services. More than a billion lack portable drinking water. In much of the world these numbers are rising, not falling.

  • Incidences of some water-related diseases are rising; resistance to drugs is increasing; and disease ranges are expanding.

  • The amount of land irrigated per capita is falling, and competition for agricultural water from cities is growing.

  • More than 700 species of fish are formally acknowledge to be threatened or endangered.

  • Political and military conflicts over shared water resources are on the rise in some regions.

  • Groundwater overdraft is accelerating. Unsustainable groundwater use occurs on every continent except Antarctica.

  • The scientific community has acknowledged that human interference in global climate is now evident and that the hydrologic cycle will be seriously affected in ways we are only now beginning to study.

(SOURCE: Peter Gleik. The World's Water: The Biennial Report on Freshwater Resources. 1998. Island Press. Washington DC)


H20 - The Mystery, Art, and Science of Water
Chris Witcombe and Sang Hwang
Sweet Briar College