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, climate change and aspirational lifestyles act as powerful catalysts on this thirsty combination, ensuring no respite from unsustainable demand for a finite resource.
Agriculture is the most dominant of these underlying causes of water scarcity. The dynamic expansion of food grain production over the last 50 years has been achieved through high-yielding seed technologies which require generous input of chemicals and water.
The impact has been greatest in Asia where the success of the “green revolution” has been accompanied by dramatic falls in groundwater levels. The globalisation of meat and dairy-based diets has compounded the water dependency of agriculture.
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.
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. About 80% of global wastewater is returned to nature untreated.
Population growth adds fuel to all of these drivers of water scarcity. World population is projected to grow from 7.5 billion to 9.7 billion by 2050; most of this 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. 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% by 2050, based on a 2006 baseline.
World primary energy demand will increase by 30% by 2040, according to the 2016 Outlook published by the International Energy Agency. Despite the rapid growth of renewable energy capacity, dependence on traditional water-intensive mining and power generation is projected to rise in coming years.
The cumulative effect of these projections 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. The UN’s 2018 World Water Development Report warns that, by 2050, between 4.8 billion and 5.7 billion people will live in areas that are water scarce for at least one month each year.
more Water Scarcity briefings (updated April 2018)
Water Energy Food Nexus
Climate Change and Water Scarcity
Solutions to Water Scarcity
Sustainable Development Goal for Water
Access to Safe Water
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