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. And widespread political cowardice denies sufficient protection to the world’s most precious commodity.
Agriculture is the dominant underlying cause of water scarcity, accounting for 69% of all global freshwater use, rising to over 90% in South Asia. The dynamic expansion of food grain production over the last 50 years has been achieved through high-yielding seed technologies which require substantial input of chemicals and water, especially for wheat and rice. The globalisation of meat and dairy-based diets has compounded the water dependency of agriculture.
The consequence 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, as well as untreated industrial and household wastewater in cities. This is an acute problem in less developed countries where environmental regulations remain inadequate or unenforced. About 80% of global wastewater is returned to nature untreated.
Over-extraction has been most serious in India where outdated laws and complacent politicians have indulged landowners in unlimited and even free access to water, underpinned by guaranteed prices for their produce.
The energy sector is responsible for 10% of global water withdrawals, largely for cooling in thermal and nuclear power generation. Freshwater now quenches the voracious thirst of fracking, as well as more traditional technologies for extraction of coal, oil and gas.
Population growth adds impetus to all of these drivers of water scarcity. World population is projected to grow from 7.8 billion to 9.7 billion by 2050; most of this growth will occur in the largest cities of developing countries, many of which are already logistically overwhelmed by unregulated 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 Nature Conservancy estimates that 36% of cities will face water crisis 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.
In parts of India, the water table has fallen catastrophically since the so-called Green Revolution; in the Punjab, groundwater is projected to be exhausted by 2039.
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 consumerism. There has been poor understanding of the interdependence of the building blocks of human development, often described as the water energy food nexus.
Too many governments lack the coordination necessary to anticipate how policies targeting one element of this nexus will almost certainly have consequences for the other two. For example, almost half of India’s thermal power capacity is located in regions of water scarcity, suffering regular disruption to energy supplies.
Another example relates to new fossil fuel technologies such as gas fracking and oil sands. Government enthusiasm has tended to overlook the intrusion and demands on the water cycle. Fears of depletion and pollution of local water sources has played a part in the widespread public unease about these technologies.