The United States is the third largest exporter of water in the world -- a wild thought against the backdrop of a national drought. That's because every "thing" we export has a water component built into its production: a specific volume of water needed to bring a product to market. Some countries with limited water resources, like Egypt, are net water importers. But the United States is net exporter, which seems like a good idea -- until we have a drought. It's time to change how we think about water.
The "virtual" water footprint is unknown to most people, and the amounts are often surprising. An ear of corn? It takes about 110 gallons of water to grow. A pound of beef? 1,800 gallons. A pair of blue jeans? 2,800 gallons for the cotton. That footprint is what makes your nearby stream or the aquifer under your feet an international player in the global commodities market.
The beef example is instructive. Most of what we export is grain to feed animals. And of all the environmental issues of the day: endangered species, climate disruption, etc., etc., it is the changing human diet that will stress resources the most. As nations around the world develop, their appetites move up the food chain. The Economist recently illustrated this using China as the example: their increase in beef consumption from 1985 to 2009 required additional water resources equivalent to all the annual water use in Europe. In fact, total U.S. beef production requires 30 trillion gallons of water each year -- enough to drain dry six times over the Colorado River (the river that carved the Grand Canyon out of stone).
Water, the primary ingredient for all life on Earth, is precious. If all of the world's water were placed in a gallon jug, the amount of freshwater would be a mere tablespoon, with only a third of that available to humans. It gives us food production, drinking, manufacturing, and, if there's anything leftover, we leave it in streams and lakes for nature. Putting natural systems last is a bad call, because in times of drought, it is the functionality of our natural water "blue" infrastructure that can sustain plants and release cool clean water.
We have no more or less water in the biosphere than we did the day the planet opened for business, and we are clearly running up against limits: we no can longer count on good quality water to be available when we need it. The reason is that historically, we simply did not understand the impacts of our actions, and the rules of water development were set up for maximum utilization without due regard to conservation.
And this is leading to bad results. For example, aquifers, natural underground water storage built over eons, are being depleted at rates far exceeding their replenishment. These are largely governed by the rule that whoever puts the biggest straw in the ground can pump it out. Surface water has its own problems. West of Kansas, agriculture accounts for maybe 80% of all water use, with the bulk of that lost or wasted from point of diversion to point of application -- and that is acceptable under the law.
Though water is coming under pressure, we don't have a water supply problem, we have a water management problem. And it is fixable. Consumers need to understand our water footprints and reward water-efficient goods. Producers need to squeeze more crop-per-drop. Regulators need to support and incentivize agriculture to 'add-to' rather than 'takeaway-from' our blue infrastructure. All these things are doable, and critical if we intend to have an agricultural economy that is durable, even in times of drought.
The planet, of course, is run by humans. We have long altered rivers and wild landscapes to simplify and make them more useful to us. And while we need to produce food, we cannot destroy the very resources that enable that -- we will need to produce food forever. The economy is a wholly owned subsidiary of the environment -- it is the source, literally, of all the things humans use. Meeting future needs requires we make informed tradeoffs between our wants and our actions.