During the past century, while world population has tripled, the use of water has increased sixfold. Some rivers that formerly reached the sea no longer do so—all of the water is diverted before it reaches the river’s mouth. Half the world’s wetlands have disappeared in the same period, and today 20 percent of freshwater species are endangered or extinct. Many important aquifers are being depleted, and water tables in many parts of the world are dropping at an alarming rate. Worse still, world water use is projected to increase by about 50 percent in the next 30 years. It is estimated that, by 2025, 4 billion people—half the world’s population at that time—will live under conditions of severe water stress, with conditions particularly severe in Africa, the Middle East, and South Asia. Many observers predict that disputes over scarce water resources will fuel an increase in armed conflicts. Water that is safe to drink remains as central to survival—and to improving the lives of the poor—as it has always been. Currently, an estimated 1.1 billion people lack access to safe water, 2.6 billion are without adequate sanitation, and more than 4 billion do not have their wastewater treated to any degree. These numbers are likely to only grow worse in the coming decades, as the global response to the issue has thus far been weak. This seminar will discuss the global challenge of expanding access to water while managing the sustainable use of scarce water resources.