updated August 2014
Contemporary industry and agriculture account for 92% of global freshwater use. Fulfilling this demand has been motivated more by desire to increase production of food and consumer goods than concern for sustainability. This irrational global management of a finite resource is the underlying cause of water scarcity.
The consequence has been over-extraction of freshwater and pollution of surface water. Population growth and rising wealth drive this overall scenario inexorably into crisis territory. World population is projected to grow from 7.2 billion to 9.6 billion by 2050.
Water is used in great quantities for cooling in thermal and nuclear power generation, as well as in the extraction of coal, oil and gas. And the dynamic expansion of food production in Asia over the last 40 years – often described as the “green revolution” – has been achieved through modern farming methods which require high input of water.
Over-extraction has its most straightforward manifestation in the level of aquifers, underground reserves charged by the passage of water through soil and rocks. If withdrawals exceed the natural rate of recharge, the level of an aquifer will fall, eventually drying up altogether. In parts of India, the water table is believed to have fallen more than 300 metres, the lack of control exacerbated by a policy of allowing farmers unlimited and free access to water.
Surface waters are polluted by run-off of chemicals used in farming and by untreated industrial and household wastewater in cities. This is an acute problem in less developed countries where environmental and sanitation regulations remain inadequate or unenforced.
Most of the world’s population growth will occur in the cities of developing countries, many of which are already logistically overwhelmed by unregulated slum development. Whilst cities were often founded in proximity to good freshwater supplies, the benevolence of nature rarely extends to megacity concentrations of over ten million people.
The rising pressure on freshwater will be felt most acutely in the energy and food sectors. The World Resources Institute estimates that global food production must rise by 69% between 2006 and 2050.
World primary energy demand will increase by one third between 2011 and 2035, according to the International Energy Agency. Despite the emergence of renewable energy sources, dependence on traditional water-intensive mining and power generation is projected to rise in coming years.
The cumulative effect of these demand drivers will lift global demand for freshwater by 53% by 2030, according to the 2030 Water Resources Group, a consortium of private sector interests supported by the World Bank. One third of the global population, mostly in developing countries, will live in regions where demand for water exceeds supply by more than 50%.
Water in the Anthropocene charts the impact of humanity on the global water cycle
from The Global Water System Project
more Water Scarcity briefings
Definition and Goals
Water Food Energy Nexus
Climate Change and Water Scarcity
Solutions to Water Scarcity
Water Scarcity Governance
Access to Drinking Water
Source material and useful links