Water scarcity, already a pressing issue in many parts of the world, is expected to become far worse as a result of global climate change and its impact upon regional weather patterns.
A recent study by the Potsdam Institute for Climate Impact Research found that the impact of climate change on water scarcity is set to be substantial, as the earth's population balloons from seven billion people at present to between eight and 10 billion by mid-century, and changing weather patterns affect the volume, pattern and timing of both rainfall and evaporation levels.
The Institute's Multimodel Assessment of Water Scarcity Under Climate Change, published in the Proceedings of the National Academy of Sciences, employed a range of models to simulate various hydrological scenarios, and concluded that climate change is likely to increase the number of people around the world at risk of absolute water scarcity by roughly 40 per cent.
Region-wide water scarcity problems are already afflicting Brazil, where a summer of record-breaking heat and aridity has compelled 142 cities to ration their water supplies. Around 6 million people have been affected by the rationing measures, with some people forced to go for several days without water as a consequence.
Sao Paolo, Brazil's financial hub as well as South America's most populous city, is amongst the urban centres worst affected by the drought. The city's 20 million strong population is highly dependent on the Cantareira reservoir system for its water supply. The recent drought, however, has left the system with under 16 per cent of its 1 trillion litre capacity.
Fellow emerging giant China also confronts similar water scarcity problems, with the World Bank estimating that the issue costs the country more than two per cent of its GDP each year as a result of harm to human health.
China has sought to deal with the issue in a manner characteristic of its technocratic leadership - the launch of a colossal engineering project to divert water from country's wet, riverine south to its parched northern plains.
The South-North Water Transfer Project is a multi-decade infrastructure program which will eventually channel 44.8 billion cubic metres of water per annum from the Yangtze River to northern China via a trio of canal systems. The $79 billion spent on the project thus far makes it one of the most expensive engineering projects ever undertaken.
The first stage of the three-part project, which involve the use of part of the 1,400 year old Grand Canal to convey water to the north, opened last year, while second stage - a 1,200 kilometre between the Yangzi River and the capital of Beijing in the north - is scheduled for completion soon.
Despite the epic scale and exorbitant cost of the project, critics say it is unlikely to serve as anything more than a provisional remedy for China's equally gargantuan water problems.
China's water supply continues to suffer from acute mismanagement, with a lack of adequate pricing mechanisms leading to absurdly cheap water in those areas suffering from scarcity.
This leads to immense wastage by households, whose utilities bills are little affected by excess usage, and causes poor decision-making amongst officials and planners, who give their support to water-intensive business activities or construction of new urban developments in drought-afflicted areas.
Instead of vast infrastructure projects which take decades to build and come with huge price tags, sustainability experts instead advocate easy-to-deploy pricing and payment mechanisms, which will enable market processes to improve the management of water and reduce gratuitous waste.
A recent study by New York-based environmental think tank SustainAbility with the support of the Rockefeller Foundation outlines a range of market-based measures that could serve to significantly ameliorate the water scarcity issue.
One of the primary measures advocated by SustainAbility's Water Scarcity and Innovations for the Future is watershed payments, which involves downstream stakeholders incentivising upstream actors to better manage water resources through various kinds of investment.
China is already pursuing the widespread deployment of watershed payment programs to achieve incentivised management of water resources across administrative boundaries. A key example is the Min River Water Resource Eco-Compensation Program, under which the downstream city of Fuzhou pays $800 million to the upstream cities of Sanming and Nanping who in turn match this investment and adopt measures to ensure that upstream waters are kept clean.
SustainAbility also advocates the development of trading markets for water benefit certificates as an innovative and effective means for achieving improved management of scarce water resources.
The scheme would operate in a manner similar to carbon emissions trading, with tradable credits created by the certification of projects which either deliver a set volume of clean water units or provide some other form of water benefit.