Water security for a planet under pressure: interconnected challenges of a changing world call for sustainable solutions

Abstract

Sustainability, equitable allocation and protection of water resources must occur within the framework of integrated management and water governance, but its implementation is problematic. Ongoing global climate change, increasing population, urbanization, and aspirations for better living standards present a challenge to the planetary sustainability. While water use at global scale currently seems to be within its planetary boundary, shortages prevail in several water-scarce and overpopulated regions, and are projected to increase. Furthermore large-scale impoverishment of aquatic biodiversity, ecosystem degradation and reductions in water quality are unaddressed `side effects' in areas where water can be secured for human and economic uses. As the world prepares for Rio+20, challenges to the sustainability of global water security should be scrutinized. Of particular concern is the likelihood that the water-related Millennium Development Goals (MDGs) targets may not be achievable due to lack of funding commitments, and a failure of delivery mechanisms including water governance. Constraints on water availability and reductions in water quality jeopardize secure access to this resource for all legitimate stakeholders, including aquatic and terrestrial ecosystems. Water connects several socio-ecological, economic and geophysical systems at multiple scales and hence constitutes a `global water system'. This should be considered both in technical interventions and in governance frameworks. Humans have been changing the global water system in globally significant ways since the industrial revolution, yet without adequate knowledge of the system and its response to change; and without sufficient understanding of how to govern the system at local and global scales. Water security in the 21st century will require better linkage of science and policy, as well as innovative and cross-sectoral initiatives, adaptive management and polycentric governance models that involve all stakeholders. Consensus solutions will need to be achieved by evidence-based mediation, rather than following untested `panaceas', so as to ensure equitable and sustainable global water use.