Will we run out of fresh water in the 21st century?

Will we run out of fresh water in the 21st century?

I do see a looming global water crisis, and it’s actually three separate crises—one of access, one of pollution, and one of scarcity—that do not lend themselves to simple solutions.

Answer provided by Upmanu Lall, the Alan and Carol Silberstein Professor of Earth and Environmental Engineering and of Civil Engineering and Engineering Mechanics
Photo by Eileen Barroso
Each is inexorably linked not only to the others but also to other intractable problems like climate change and population growth.
In response to these crises, I helped found the Columbia Water Center in 2008 in order to address climate risk management, development and the environment, and food security across a range of temporal and spatial scales. We need to view what we think of as a local crisis as a global one – it’s imperative that we address the global elements of individual, “localized” problems, like the possibility that North India may run out of groundwater in a decade, leading to a collapse of agriculture in India. As it stands, industrial development of such regions is impacted by the lack of reliable electricity as much of the energy use is dominated by its use for groundwater pumping.
Mechanical Engineering Professor Vijay Modi is also working with a Columbia team on this issue focusing on Gujarat, India, where he is working with the state government on strategies to facilitate a transition away from energy subsidies for groundwater pumping.
In fact, one of the key players in the looming water crisis is agriculture, which accounts for 70 percent of global water use on average and more than 90 percent in arid regions. We might be able to dramatically improve the efficiency of water use by improving irrigation systems, by changing the way farmers water their crops, and by changing where different crops are grown. In fact, all these measures will need to be effected even if our sole goal was adaptation to climate change and variability.  Agricultural water use efficiency is not much higher in the United States than in many developing countries. Agricultural water pollution due to the way fertilizers, herbicides, and pesticides are used is also a significant global factor. 
We could also improve water use by improving food processing, storage, and delivery as a means of reducing the 30 to 40 percent food loss that currently occurs post agricultural production. With one-third of the developing world expected to confront severe water shortages in this century, this is not a problem that we can ignore or avoid, and we’re working hard at the Columbia Water Center to find answers.
Reducing regional water scarcity provides benefits also for improving access to water and helping reduce pollution by making more water available for dilution. Nevertheless, controlling pollution sources more directly and improving the energy and land efficiency of water and wastewater treatment also emerge as important goals for any water strategy across the world.
At Columbia, work is also being done in these directions by Ponisseril Somasundaran, the LaVon Duddleson Krumb Professor of Mineral Engineering, and assistant Professor Kartik Chandran in the Department of Earth and Environmental Engineering. Somasundaran is part of a group of researchers developing low cost, low maintenance water purification systems to remove or deactivate toxic concentrations of arsenic, nitrates, sulphates and fluorine and to recover water from millions of gallons of waste sludges impounded in ponds and lakes. Chandran, whose work is in engineered wastewater treatment technologies that are enabled by environmental microbiology and biotechnology, is working to create environmentally sustainable wastewater treatment.
Finally, as to the question of access, it is now well publicized that nearly 3 billion people in the world lack access to safe drinking water, and need cost effective and reliable solutions. Even where international organizations tried to develop solutions for such problems, often they have not just failed but created new problems, An example is Bangladesh, where external efforts to control biological disease from unsafe water led to the development of shallow groundwater sources that proved to be high in Arsenic leading to the mass poisoning of tens of millions of people.
Professors Graziano from the Columbia School of Public Health and Dr. van Geen from the Lamont Doherty Earth Observatory are leading a research team at Columbia that is focused on reducing arsenic exposure in Bangladesh through a better understanding of the processes behind the arsenic contamination. This understanding is enabling inexpensive solutions for providing people more reliable access to clean, arsenic-free water. A sister project led by Professors Culligan and Dr van Geen is also examining how to reduce exposure of the Bangladeshi people to microbial contamination of their drinking water. Such exposure is still causing severe and detrimental health effects among the children of this impoverished country.
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