Oil may make more headlines, but water is the world’s most indispensable resource, and a dwindling one. Water’s scarcity spawns war, epidemic diseases and the collapse of states across parts of Africa and Asia; its faltering supplies imperil the rise of China and India. What should we do about water? Journalist Steven Solomon, author of Water: The Epic Struggle for Wealth, Power, and Civilization, visits Zócalo to trace the history of water from ancient times to our dawning age of scarcity.