This report, prepared by the World Water Assessment Programme under UNESCO (UN Educational, Scientific and Cultural Organization), assesses global freshwater resources including what drives the pressures facing them, how water is used, climate change's future effects on water supplies and options for improving water management for sustainable development.

The authors highlight the increasing demand for water, outlining the demographic, economic and social factors — such as population growth, international trade and changing lifestyles. They argue that climate change will undoubtedly affect water resources, impacting water quality and the frequency of extreme events such as droughts or flooding.

Investment in the water sector is important, say the authors — to improve access to clean water as well as decrease pollution from untreated sewage discharge. International donors must play a part in improving water infrastructure in the developing world, they add.

But how individual countries respond will depend on their own development objectives, capacity and political framework. The authors outline options for policymakers to increase supply, manage demand, reduce losses and reallocate resources.