Water, water, everywhere!

Here, in the United States, where I now reside, the 2011-2017 California drought, was the most severe in history, since record keeping began; while the atmospheric river enhanced floods in 2017, made Northern California witness the wettest winter in a century. The disastrous 2011 floods in Thailand, which besides causing severe loss of Thai lives and property, also led to a global shortage of computer hard disk drives accompanied by a dramatic rise in prices, which were preceded in 2010 by a record low-level of water in the dams. An opinion article, in The Guardian, by Raghu Karnad, dated September 4, 2017, was titled: "Floods in drought season: is this the future for parts of India?" These cycles of an extreme deluge and severe droughts across regions of the globe correspond to three of the highest risks reported in the World Economic Forum's 2017 Global Risk Report, specifically, extreme weather events, natural disasters, and water crises. The immortal words of Samuel Taylor Coleridge have turned out to be more prophetic than even the great poet may have ever thought possible: "Water, water, everywhere, nor any drop to drink".

The United States National Academy of Engineering (US NAE) lists "Provide Access to Clean Water" as one among the 14 Grand Challenges for Engineering in the 21st Century. The US Agency for International Development (USAID) notes, "Securing Water for Food" as one of 10 Grand Challenges for Development. Water-related risks may be categorised into Resources, Hazards, and Nexus. We could define water resources to include quantity and quality, especially since both relate to drinking water availability. Groundwater and surface water reduction, as well as greater demand, stress water availability, as can be witnessed in the South-West United States, the Middle East, Sahel region of Africa, and parts of China and the Indian subcontinent. The presence of arsenic in the waters of Bangladesh and West Bengal in India, harmful algal blooms from Lake Erie in the USA to Kunming in China, and water-borne diseases across the developing and emerging economies, are stark harbingers. The green slime that came out of water taps in Toledo, the fourth largest city in Ohio, for several days in August 2014, and the high levels of lead in the waters of Flint, Michigan, from 2014 onwards, are reminders that even developed nations are not immune. Water-related hazards include floods and droughts. Floods may last from hours to even a few months, with disastrous impacts on agriculture, human lives and health, as well as on the urban economies. Droughts may span timescales from weeks and months to decades and even centuries, causing untold misery to farmers and to food or energy scarcity. Droughts have brought famines in lands of plenty and even destroyed flourishing civilisations. Water forms a tight nexus with food and energy; with energy dominating in developed economies and food elsewhere. Water impacts human health (including water-borne diseases), ecosystems, critical infrastructures, and lifelines. The three-way feedback among water, population and climate, and their relation to conflicts and diplomacy have been discussed many times elsewhere. An Op-Ed published on October 31, 2017, in the New York Times by Tom Friedman, which discussed the "cocktail of climate change, desertification … population explosions and misgovernance" in the context of destabilisation of Niger and other African countries in the Sahel, is only one recent example.

The concept of "peak water" was defined by Peter Gleick and Meena Palaniappan in their 2010 peer-reviewed article in the Proceedings of the National Academy of Science. The New York Times defined "peak water" (like peak oil) as "a theory that, humans may have used the water easiest to obtain, and that scarcity may be on the rise", in an article that selected this phrase as among their 33 "words of the year [2010]". Peter Brabeck-Letmathe, the erstwhile CEO and Chairman of the Board at Nestle, restated his beliefs in a video on the company's website: "Everyone should have clean, safe water to meet their fundamental daily needs … water scarcity is the greatest challenge we face today." He goes on to say that water should be better managed, preserved and valued, and highlighted its impacts on agriculture. As the United Nations has documented and scientists across the world have reported, our own peer-reviewed research also points to future intensification of heavy precipitation with impacts on critical infrastructures, more severe and widespread droughts, power production at risk from warmer and scarcer waters, and significant water stress resulting from both climate and population shifts.

There are costs to both action and inaction. Fundamental changes motivate transformative adaptations, while unwieldy uncertainties constrain policy decisions. Uncertainties arise from the inherent difficulty in projecting policy or institutional behaviour, but also because of our lack of understanding of the interconnected natural, engineered, and human systems, and in assessing their inherent variability. We cannot design or prepare exclusively based on history, especially since unprecedented extremes or severe stresses related to water may no longer be unsurprising. We cannot design for average change since lives or property lost from floods or droughts do not cancel out each other. We cannot possibly design for the worst-of-the-worst since there are and will always be competing economic considerations. The challenges in the dimensions of science, engineering, and policymaking are immense. Cautious pragmatism rather than retrograde denialism or overzealous activism may be necessary. "The best lack all conviction," wrote William Butler Yeats in The Second Coming, "while the worst are full of passionate intensity." We would all be wise to remember these words in times of need.

However, opportunities abound. Predictive understanding of the relevant natural and social sciences, as well as built systems, have been increasing over the last several decades. Advances in water, energy, agricultural, health, infrastructural, and sensor technologies have paved the way for innovations in engineering design and operations. New out-of-the-box thinking has led to novel policy prescriptions, enhanced regulatory principles, and better strategies for conflict resolution, as well as novel financial incentive structures. Transformative solutions across the relevant sciences, engineering and policy disciplines have been enabled by new developments, including in artificial intelligence, machine learning, nonlinear physics, engineering principles, and econometrics. The future is not necessarily all doom and gloom, but the call to action is unmistakable.

This brings me to the mythical Cassandra of Troy. Her prophecies, while true, were disbelieved. This ultimately contributed to the destruction of Troy by the Greeks. Planet Earth is the new Troy! Charlatans and myopic policymakers are the new Greeks. Scientists, engineers, and policy analysts, from across academia, the private sector, and government agencies, have conveyed their projections. We have been duly warned by our Cassandras. The choice to listen and act, like that of ancient Trojans, is ours!