We should be worried about the state of water resources. I doubt there is a single current affairs publication that has not addressed this "global water crisis". On balance they raise legitimate concerns.
In the next twenty years, we will need to supply roughly 40 percent more water than we do today to support greater economic activity, from food to energy production. Because almost half of global food production comes from 20 percent of cultivated land that is under irrigation, it is unlikely that we are going to meet the food requirements of a growing and wealthier population without capturing, storing and delivering more water.
The traditional solution to this is to build new infrastructure—reservoirs, dams, canals. This may very well be the right answer in some places, particularly in those countries that have yet to build much of their water infrastructure, but overall may prove to be too expensive to be the only solution.
We must change the way in which we use water, doing more with less. Unfortunately we do not have a great track record in increasing resource productivity. In 1967, the American National Academy of Sciences established the "Committee on Resources and Man" to answer that neo-Malthusian question: Are we able to increase our resource productivity so as to not exhaust the planet? Or is our exponential growth a precursor of ecosystem collapse on a global scale? Almost fifty years later, the good news is that we are still here. The bad news is that, as envisioned by the committee, our increased productivity has not proven sufficient: in water, as in other resources, so far it has been outstripped by demand growth.
But concerns for water don't stop at issues of quantity. In developed countries, thousands of soluble chemical compounds are making their way into water bodies in trace concentrations. Pharmaceuticals, from anti-inflammatories to anti-depressants, personal care products, detergents, pesticides, various hydrocarbons, the list is long and growing. Whether or not some of these will turn out to have significant epidemiological consequences remains to be seen, but in most cases standard treatment technologies are not designed to intercept them.
We are not doing so well on the ecosystems front either. I sometimes have the impression that freshwater conservation is perceived to be only a concern for middle-aged accountants with a passion for fishing. It should not: More than a quarter of all vertebrate species on the planet live in rivers. We have proportionally lost more species in freshwater ecosystems than in any other. That deterioration is also bad news for us. Biologically well-functioning rivers and adjacent ecosystems may well be a necessary counterweight to increasing our use of water resources for economic activities: If we are to grow intensive irrigated agriculture and fertiliser use, functioning riparian ecosystems are essential to mitigate their impact and ensure costs for potable treatment don't grow unchecked; if we want management of flood risks to be more resilient in the face of climate change, we will have to increasingly blend hard infrastructure with functioning wetlands.
So we have cause for concern, no question about it. That said, when it comes to water, "worry", particularly that of a catastrophic nature, is a singularly unhelpful sentiment. Water systems are not simply a feature of our landscape that needs to be protected from human activities. They are a foundational element of our societies and a basic infrastructure for our economies. That they are subject to so many competing, and at times incompatible, interests is an inevitable consequence of their critical importance in virtually everything we do.
Reams have been devoted to rousing alarms about the global water crisis, but the barrier to effective action is not one of conviction, but of complexity. It is frightening that—outside of a restricted circle of practitioners—we have been unable to develop a fact based, practical way of debating water issues in public. We do not need great public debates on the likelihood of "water wars" or the popular yet mistaken idea that water is an exhaustible resource. But we do need debates on the practical, consequential choices we have.
How should we think about the trade-offs between food production and water scarcity? What options do we have on hydropower and what are their costs? What does an economy consistent with the available resources look like? Precisely because managing water for multiple objectives is complex and solutions are always contextual, we must make sure that people know what questions to ask and understand the trade-offs they will have to live with.
For many countries, ensuring there is enough water to sustainably satisfy the needs of growing population and economy will be a complicated and expensive balancing act. 600 billion dollars are spent each year on managing water, comparable to what is spent globally on natural gas. And this does not include expenditure in other sectors—from agriculture to manufacturing—that influences the intensity of water use.
Historically, governments financed most of those expenditures, and negotiated trade-offs between competing objectives as part of their ordinary administrative process. But today few public institutions have access to the necessary funds to simply pay for such investments, and many struggle to access affordable finance. Even when they do, the question of managing water resources is no longer just administrative. As we strain what we can do with our limited resources, choices across the economy become increasingly interconnected: Industrial policy, energy, agricultural choices become water choices, and the environmental outcomes we seek for our rivers have implications for jobs and economic development.
These are profoundly political and value-laden issues that deserve informed public debate. People must be able to have accessible debates about the trade-offs that they are asked to live with, just like they do—or should do—with other collective strategic issues, from energy to health care. If they don't, our economies, societies and environment will inevitably be all the poorer for it.