This World Water Assessment Programme Special Report brings together messages on water and climate change from the World Water Development Report 3: Water in a Changing World. Water in a Changing World shows that changes in our water resources are shaped to a great extent by a number of key externalities, among them climate change, and that decisions taken far from the conventionally defined water sector have a tremendous influence on water resources and how they are used or misused. The report also describes the dynamic linkages that interconnect changes in climate, the state of our water resources, demographic expansion and migration issues, food and energy shortages, and the continuing challenge of poverty. Rather than addressing these issues in isolation, it argues that a holistic approach is crucial if we are to solve the crises we face today and avoid worse crises tomorrow.