Water security in one blue planet: Twenty-first century policy challenges for science

Abstract

Water-related risks threaten society at the local, national and global scales in our inter-connected and rapidly changing world. Most of the world's poor are deeply water insecure and face intolerable waterrelated risks associated with complex hydrology. Most of the world's wealthy face lower waterrelated risks and less complex hydrology. This inverse relationship between hydrological complexity and wealth contributes to a divided world. This must be addressed if global water security is to be achieved. Using a risk-based framework provides the potential to link the current policy-oriented discourse on water security to a new and rigorous sciencebased approach to the description, measurement, analysis and management of water security. To provide the basis for this science-based approach, we propose an encompassing definition rooted in risk science: water security is a tolerable level of water-related risk to society.Water security policy questions need to be framed so that science can marshal interdisciplinary data and evidence to identify solutions. We join a growing group of scientists in asserting a bold vision for science leadership, calling for a new and comprehensive understanding of the planet's water system and society's water needs. © 2013 The Author(s) Published by the Royal Society. All rights reserved.