Of all the water on Earth, less than 3 percent is available for human use, and as climates change and populations boom, the strategies used to extract it will become increasingly complex. With increasing demand, policymakers, scientists and leaders must recognize the energy-water nexus. The energy-water nexus describes an interdependent relationship that exists between availability of water resources and the energy required to obtain, distribute and utilize them. The way we manage the delicate relationship between energy and water will have major implications for the future of both critical resources, as EARTH explores in the July issue.