Water scarcity already affects every continent. Around 1. 2 billion people, or almost one-fifth of the world’s population, live in areas of physical scarcity, and 500 million people are approaching this situation. Another 1. 6 billion people, or almost one quarter of the world’s population, face economic water shortage (where countries lack the necessary infrastructure to take water from rivers and aquifers). Water scarcity is among the main problems to be faced by many societies and the World in the XXIst century.
Water use has been growing at more than twice the rate of population increase in the last century, and, although there is no global water scarcity as such, an increasing number of regions are chronically short of water. Water scarcity is both a natural and a human-made phenomenon. There is enough freshwater on the planet for six billion people but it is distributed unevenly and too much of it is wasted, polluted and unsustainably managed. Click on map to enlarge Sources: Vital Water Graphics. UNEP Human Development Report 2006. UNDP, 2006 Coping with water scarcity.
Challenge of the twenty-first century. UN-Water, FAO. 2007 Water Scarcity and the MDGs The way water scarcity issues are addressed impacts upon the successful achievement of most of the Millennium Development Goals. Water stress versus water scarcity Hydrologists typically assess scarcity by looking at the population-water equation. An area is experiencing water stress when annual water supplies drop below 1 700 m3 per person. When annual water supplies drop below 1 000 m3 per person, the population faces water scarcity, and below 500 cubic metres “absolute scarcity”.
Water scarcity is defined as the point at which the aggregate impact of all users impinges on the supply or quality of water under prevailing institutional arrangements to the extent that the demand by all sectors, including the environment, cannot be satisfied fully. Water scarcity is a relative concept and can occur at any level of supply or demand. Scarcity may be a social construct (a product of affluence, expectations and customary behaviour) or the consequence of altered supply patterns – stemming from climate change for example. Sources: Vital Water Graphics.
UNEP Coping with water scarcity. Challenge of the twenty-first century. UN-Water, FAO. 2007 Did you know? Around 700 million people in 43 countries suffer today from water scarcity. By 2025, 1. 8 billion people will be living in countries or regions with absolute water scarcity, and two-thirds of the world’s population could be living under water stressed conditions. With the existing climate change scenario, almost half the world’s population will be living in areas of high water stress by 2030, including between 75 million and 250 million people in Africa.
In addition, water scarcity in some arid and semi-arid places will displace between 24 million and 700 million people. Sub-Saharan Africa has the largest number of water-stressed countries of any region. UN initiatives that are helping to raise the issue… World Water Day 2007: Coping with water scarcity World Water Day 2007 was dedicated to the theme “Coping with water scarcity”. It highlighted the increasing significance of water scarcity worldwide and the need for increased integration and cooperation to ensure sustainable, efficient and equitable management of scarce water resources, both at international and local levels.