updated February 2017
The direct cause of water scarcity is the insatiable need for freshwater in modern industry, agriculture and extractive technologies. The further dependence of these sectors on energy generation, itself water intensive, compounds the demand. Population growth and climate change act as indirect catalysts on this dynamic imbalance between supply and demand.
The energy sector is responsible for 10% of global water withdrawals, largely for cooling in thermal and nuclear power generation. Further water resources are required in the extraction of coal, oil and gas. And the dynamic expansion of food grain 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. The globalisation of meat and dairy-based diets further adds to the water dependency of agriculture.
The consequence of these trends has been the over-extraction of freshwater and pollution of surface water that together create scarcity. 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.
Population growth adds fuel to all of these drivers of water scarcity. 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 World Bank has warned that water availability in cities could be reduced by as much as two thirds by 2050.
Politicians cannot excuse their inadequate response to water scarcity on grounds of ambiguous environmental science. The symptoms of unsustainable consumption of a critical natural resource are explicit.
A quarter of the world’s rivers fail to complete their natural journey to the sea, including the once mighty Yellow River in China and the Murray-Darling River in Australia. Where rivers do flow, pollution often destroys fish and aquatic life which once provided protein and livelihoods. Pioneering satellite-based measurement has revealed that 21 out of 37 of the world’s major aquifers are being exploited unsustainably, their levels falling dramatically
Despite these environmental distress signals associated with water scarcity, government policies on freshwater have generally bowed to the insatiability of modern lifestyles. Political will is challenged still further by unnerving projections of the drivers that will determine future demand for freshwater.
This rising pressure will be most acute 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 30% by 2040, according to the 2016 Outlook published by 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.
Population growth and rising wealth drive this overall scenario inexorably into crisis territory. World population is projected to grow from 7.3 billion to 9.7 billion by 2050.
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. USAID has warned that “by 2025, two-thirds of the world’s population could be living in severe water stress conditions.”
Water in the Anthropocene charts the impact of humanity on the global water cycle
from International Geosphere-Biosphere Programme
Water is Life. Don’t UnderMine It
An animation of contrasting waterway journeys reveals how mining is damaging the water cycle
from The Gaia Foundation
more Water Scarcity briefings
Water Energy Food Nexus
Climate Change and Water Scarcity
Solutions to Water Scarcity
Sustainable Development Goal for Water
Access to Drinking Water
Source material and useful links