Many conflicts are caused or inflamed by water scarcity. From Chad to Darfur, to Ethiopia's Ogaden Desert, to Somalia and its pirates, and across to Yemen, Iraq, Pakistan and Afghanistan, the conflicts lie in a great arc of arid lands where water scarcity is leading to failed crops, dying livestock, extreme poverty and desperation.
Extremist groups such as the Taliban find ample recruitment possibilities in such impoverished communities. Governments lose their legitimacy when they cannot guarantee their populations' most basic needs: safe drinking water, staple food crops, and fodder and water for the animal herds on which communities depend for their meagre livelihoods.
Politicians, diplomats and generals in conflict-ridden countries typically treat these crises as they would any other political or military challenge. They mobilize armies, organize political factions, combat warlords or try to grapple with religious extremism.
But these responses overlook the underlying challenge of helping communities meet their urgent needs for water, food and livelihoods. As a result, the United States and Europe often spend billions of dollars to send troops or planes to quell uprisings or target "failed states" but not even a 100th of that amount to address the underlying crises of water scarcity and underdevelopment.
Water problems will not go away by themselves. On the contrary, they will worsen unless we, as a global community, respond. A series of recent studies shows how fragile the water balance is for many impoverished and unstable parts of the world. UNESCO recently issued the 2009 UN World Water Development Report; the World Bank issued powerful studies on India (India's Water Economy: Bracing for a Turbulent Future) and Pakistan (Pakistan's Water Economy: Running Dry); and the Asia Society issued an overview of Asia's water crises (Asia's Next Challenge: Securing the Region's Water Future).
These reports tell a similar story. Water supplies are increasingly under stress in large parts of the world, especially in arid regions. Rapidly intensifying water scarcity reflects bulging populations, depletion of groundwater, waste and pollution, and the enormous and increasingly dire effects of man-made climate change.
The consequences are harrowing: drought and famine, loss of livelihood, the spread of water-borne diseases, forced migrations, and even open conflict. Practical solutions will include many components, including better water management, improved technologies to increase the efficiency of water use, and new investments undertaken jointly by governments, the business sector, and civic organizations.
I have seen such solutions in the Millennium Villages in rural Africa, a project in which my colleagues and I are working with poor communities, governments and businesses to find practical solutions to the challenges of extreme rural poverty. In Senegal, for example, a world-leading pipe manufacturer, JM Eagle, donated more than 100 kilometres of piping to enable an impoverished community to join forces with the government water agency PEPAM to bring safe water to tens of thousands of people. The overall project is so cost effective, replicable and sustainable that JM Eagle and other corporate partners will now undertake similar efforts elsewhere in Africa.
But future water stresses will be widespread, including both rich and poor countries. The U.S., for example, encouraged a population boom in its arid southwestern states in recent decades, despite water scarcity that climate change is likely to intensify. Australia, too, is grappling with serious droughts in the agricultural heartland of the Murray-Darling Basin. The Mediterranean Basin, including southern Europe and North Africa, is also likely to experience serious drying as a result of climate change.
The precise nature of the water crisis, however, will vary, with different pressure points in different regions. For example, Pakistan, an already arid country, will suffer under the pressures of a rapidly rising population, which has grown from 42 million in 1950 to a projected 184 million in 2010, and may increase to 335 million in 2050, according to the UN's "medium" scenario. Even worse, farmers are now relying on groundwater that is being depleted by overpumping. Moreover, the Himalayan glaciers that feed Pakistan's rivers may melt by 2050 as a result of global warming.
Solutions will have to be found at all "scales," meaning we will need water solutions within individual communities (as in the piped-water project in Senegal), along the length of a river (even as it crosses national boundaries), and globally, for example, to head off the worst effects of climate change. Lasting solutions will require partnerships among government, business and civil society - which can be hard to negotiate and manage since these different sectors of society often have little or no experience in dealing with each other and may mistrust each other considerably.
Most governments are poorly equipped to deal with serious water challenges. Water ministries are typically staffed with engineers and civil servants. Yet, lasting solutions require a broad range of expert knowledge about climate, ecology, farming, population, engineering, economics, community politics, and local cultures. Government officials also need the skill and flexibility to work with local communities, private businesses, international organizations and potential donors.
A crucial next step is to bring together scientific, political and business leaders from societies that share the problems of water scarcity - for example, Sudan, Pakistan, the U.S., Australia, Spain and Mexico - to brainstorm about creative approaches to overcoming them.
Such a gathering would enable information-sharing, which could save lives and economies. It would also underscore a basic truth: The common challenge of sustainable development should unify a world divided by income, religion and geography.
Jeffrey Sachs is a professor of economics and director of the Earth Institute at Columbia University.