SWOT will point not one but two radars—tethered to each other by a thirty-foot boom—toward the Earth. Like two giant police radar guns they will stare down at the planet, zapping millions of rivers, lakes, coastlines, and other wet spots on its rotating face while hurtling through orbit at over fifteen thousand miles per hour. Even one SWOT satellite will stream three-dimensional water-level maps of the entire world, day and night. This technology will constantly scan the pulse of the planet’s plumbing. It will unveil its throbs and ebbs of circulating water in all their complexity for the first time. Then, we will post the data online for free.
Billions care about the fate and availability of their water. Especially where it is scarce, little information is available, and lives depend on it. Our satellite is currently wending its way through the political labyrinth of being approved, built, and launched. We are hoping it can be up and orbiting by 2018. But regardless of SWOT’s particular fate, I am confident that by 2050, its successors will have made globalized water resource information transparently available for everyone and everywhere on Earth, as has now been done very successfully with other kinds of satellite data.216 No more water secrets or scientific question marks. It will completely transform the way we study and manage our most vital natural resource.
Wars over Water?
It has become fashionable to declare water the “next oil,” over which the world is bracing to go to war in the twenty-first century. Googling “water wars” yields over three hundred thousand hits; the phrase is showing up in scholarly articles as well as newspaper headlines.217 “Fierce competition for freshwater,” said U.N. secretary general Kofi Annan in 2001, “may well become a source of conflict and wars in the future.” His successor, Ban Ki-Moon, in a 2007 debate of the U.N. Security Council, warned of water scarcity “transforming peaceful competition into violence,” and floods and droughts sparking “massive human migrations, polarizing societies and weakening the ability of countries to resolve conflicts peacefully.”218
International relations professor and journalist Michael Klare gets more specific. He expects four rivers in particular—the Nile, Jordan, Tigris-Euphrates, and Indus—to provoke “high levels of tension along with periodic outbreaks of violent conflict.”219 Those four are good picks. They are already oversubscribed, and shared between sworn enemies. The Jordan River’s water is divided among Israel, Jordan, Lebanon, Syria, and the occupied Palestinian territories. Tigris-Euphrates water is used by Iraqis, Iranians, Syrians, Turks, and Kurds. The Indus is shared by Afghanistan, China, India, Pakistan, and Kashmir. The Nile and its tributaries are controlled by eight other countries besides Egypt.
Virtually all of the water flowing down these four river systems is in use today. By 2050, depending on the basin, their dependent human populations will jump anywhere from 70% to 150%. This means that for a vast area, from North Africa to the Near East and South Asia, human demand for water is rapidly overtaking available supply. “Now at the dawn of the twenty-first century,” Klare warns, “conflict over critical water supplies is an ever-present danger.”220
Scary stuff. But will the world really go to war over water? Here is a pleasant surprise: History tells us that while international conflicts over water are very common, nearly all of them—at least so far—are peacefully settled. A close reading of history reveals that while water and violence are often associated, countries rarely resort to armed violence over water.221
Peter Gleick at the Pacific Institute and Aaron Wolf at Oregon State University maintain historical databases of past conflicts and their causes.222 These reveal a rich soap opera of tensions, conflicting interests, and contentious relations, but not outright war—at least not between sovereign countries or specifically over water resources. Most commonly, the violence they document identifies water as a tool, a target, or a victim of warfare—but not its cause.223
Remarkably, successful water-sharing agreements are common even between hydrologically stressed countries that go to war over other things. Wendy Barnaby, editor of Britain’s People & Science magazine, points out that India and Pakistan have fought three wars, yet always have managed to work out their water disputes through the 1960 Indus Water Treaty.224 The reason is purely rational: By cooperating, both countries are able to safeguard their core water supply. Water is too important to risk losing in a war. Israel’s water independence ran out in the 1950s, Jordan’s in the 1960s, and Egypt’s since the 1970s. But their wars have never been fought over water. It’s amazing, because these countries no longer have enough even to grow their food.
Instead, they all import someone else’s water . . . in the form of grain.
The Virtual Water Trade
The most skilled diplomats in the world couldn’t stop a water war if people were starving. What enables sworn enemies to coexist, with large and growing populations, along a dwindling dribble like the Jordan River? Ten million people living between it and the Mediterranean Sea, with barely enough water to grow a fifth of their food? The answer is global trade flows of food.
The single biggest users of water are not cities but farms. Fully 70% of all human water withdrawal from rivers, lakes, and aquifers is for agriculture.225 Because agricultural products require water to grow, they essentially have water resources “embedded” within them. The export and import of food and animals, therefore, amounts to the export and import of water.
This “virtual water trade” is the globalized-world solution to the ancient problem of having abundant water in some places and not enough in others.226 From the global perspective, it is also less wasteful. It takes far more water to grow an orange in the baking dry heat of Saudi Arabia than to grow the same orange in humid Florida. Hidden inside Mexico’s imports of wheat, corn, and sorghum from the United States is the import of seven billion cubic meters of virtual water a year. Not only does this help Mexico—now in its fifteenth year of drought—it also requires less water overall. To produce that same amount of grain domestically, Mexico would need nearly sixteen billion cubic meters of freshwater per year, almost nine billion more. That single trade relationship saves enough water to flood the entire United Kingdom under an inch and a half of standing water.
The virtual water trade is a little-discussed secret not publicized by political leaders. Most people don’t enjoy hearing that their country is food-dependent, or that it uses its water to support others. North America is the world’s biggest exporter of virtual water. Many countries—including much of Europe, the Middle East, North Africa, Japan, and Mexico—are net importers. Unbelievably, about 40% of all human water consumption is moved around in this way, embedded in global trade flows of agricultural and industrial products.227 Without these flows the world would look very different than it does today. Dry places would support far fewer people. Lacking distant markets, large areas of terrific farmland would either surge in population or become abandoned. Global trade may be bad for local economies, bad for energy consumption, bad for resource exploitation, bad for other things . . . but it’s also spreading the wealth—of water—around.
Despite its endless recirculation, there are parts of the hydrologic cycle that smell suspiciously like depletion of a finite natural resource. This is especially true for underground sources, collectively called groundwater.
Groundwater is a very attractive water source. Unlike rainfall and rivers, which have tiny holding capacity and variable throughput, aquifers hold large volumes and are relatively stable. Humans have dug wells for thousands of years—the Egyptians, Chinese, and Persians had them as early as 2000 B.C. However, wells more than seventy to eighty feet deep are a modern invention, brought about by centrifugal pumps and the internal combustion engine.228 In water-scarce areas this new technology quickly triggered a water-drilling boom, much like the oil-drilling boom described in the previous chapter. We became a horde of mosquitoes, piercing and probing the planet with steel proboscises in search of fluids.
Tapping subterranean water meant that farmers could
convert drylands and deserts into lush, productive fields virtually overnight. Here’s a dirty little secret about the agricultural “green revolution” of the latter half of the twentieth century. The green revolution was brought about not only by new petrochemicals, hybrid seeds, and mechanized agriculture, but also by a massive ballooning in the pumping of groundwater to irrigate crops. In just fifty years the world’s irrigated land area doubled from 60 million acres in 1960 to 120 million and growing by 2007.229 Much of that irrigation water came from underground. Today, many farmers in California, Texas, Nebraska, and elsewhere are utterly dependent upon groundwater for their livelihoods.230
A common misconception about groundwater arises from photographs of headlamp-wearing spelunkers wading through mysterious dark pools in underground caverns. Actually an “aquifer” is rarely a subterranean river or pool but instead just a geological layer of saturated sediment or bedrock, the best material being porous sand.231 Water is removed from the aquifer by drilling a hole into the layer and installing a pump to raise water to the surface. This creates a cone of depression in the water table, causing surrounding groundwater to ooze through the porous matrix toward the borehole, providing a continuous water supply. Water raised from deep aquifers is normally reliable, clear, cold, and delicious. Deep aquifers don’t flood or go into drought. In some of our driest, most water-stressed civilizations, it is the discovery and tapping of giant aquifers—ancient relicts that took many thousands of years to form—that has watered cities and exploded lawns across deserts from Texas to Saudi Arabia.
The problem is that no one knew or cared where the groundwater came from. In the early days many drillers thought it was infinite, or replenished somehow by mysterious underground rivers. But because aquifers are ultimately recharged by whatever rainfall manages to percolate down from the surface, they refill slowly. If water is pumped out faster than new water can ooze in, the aquifer goes into overdraft. The water table drops and wells fail. Farmers drill deeper, then the wells fail again. Eventually the aquifer is depleted or lowered too far to raise, and becomes uneconomic.
We are now coming to appreciate just how widespread this problem is globally, by measuring small variations in the Earth’s gravity field precisely from space. In 2009 researchers using the NASA Gravity Recovery and Climate Experiment (GRACE) satellites discovered that despite natural recharge, groundwater tables in heavily irrigated parts of the Indian subcontinent are falling between four and ten centimeters per year, an unsustainable decline in an area supporting some six hundred million people.232
Most irreversible is groundwater overdrafting in our driest places. Not only do these aquifers have very low rates of rainfall recharge—and thus faster overdraft—but they are very often the main or only water source upon which people depend. Once gone, they take thousands of years to refill, or may never refill at all because they are relicts left over from the end of the last ice age. For all intents and purposes fossil groundwater, like oil, is a finite, nonrenewable resource. Eventually, the wells must run dry.
Death of a Giant
The Ogallala is a monster aquifer underlying no fewer than eight states across the western United States.233 Its existence had been known to High Plains ranchers and dryland farmers since the 1800s, but it wasn’t until the 1940s—with the arrival of modern pumps powered by electricity or natural gas—that the spigot could be opened wide. Since then, we have been pumping seven trillion gallons of cold, clear water out of the Ogallala Aquifer to irrigate circular center-pivot fields of wheat, cotton, corn, and sorghum across the Great Plains. This soon transformed over one hundred million acres of highly marginal land—much of it abandoned after the 1937 Dust Bowl—into one of the world’s most productive agricultural regions. From your airplane window or a Web-browser view from Google Earth, you can see for yourself the green circles stamped out across the Texas and Oklahoma panhandles through eastern Colorado, New Mexico, and Wyoming; and running north through Kansas and Nebraska all the way to southern South Dakota. Those verdant, neatly aligned disks are the telltale fingerprints of the Ogallala Aquifer.
Zoom in with your Web browser and you’ll see many of the disks are brown. By 1980 it was common knowledge that wells were falling fast in the Ogallala’s southern half. By 2005 large portions had fallen by 50 feet, 100 feet, even 150 feet, in southwestern Kansas, Oklahoma, and Texas. Wells in the wetter northern half were holding up fine thanks to much higher natural recharge rates, but the dry southern states, where the Ogallala water is mostly of Pleistocene age,234 was in serious overdraft. Wells began sputtering. Texas farmers, accustomed to feeding one or more center-pivot fields from a single well, began drilling several wells to support a single field.
In 2009 a team led by Kevin Mulligan, a professor of economics and geography at Texas Tech, completed a detailed study of just how fast Texas farmers are emptying out the southern Ogallala. Using a Geographic Information System (GIS), his team mapped thousands of wells throughout a forty-two-county area of northern Texas. They used the wells’ water-level and flow-rate data to calculate the remaining saturated thickness of the Ogallala, and how fast the water table is falling. From these data they constructed a series of maps projecting the remaining useful life expectancy of the aquifer, for ten, fifteen, and twenty-five years into the future.
The results were shocking. Texas’ Ogallala Aquifer is dropping an average of one foot per year and in some places as much as three feet per year. Many areas are careening toward a saturated thickness of just thirty feet, at which point the last wells will begin to suck air.235 These maps are incredibly precise—all of the thousands of individual wells and the green crop circles they support are shown—so the impending demise of the aquifer is mapped out in a very detailed way. Texas’ Parmo and Castro counties are plastered with center-pivot crops today, but their lush surface belies the situation below. Both counties are facing the abandonment of irrigated agriculture within the next twenty-five years.
Might the southern Ogallala be saved by sound conservation measures, like converting to drip irrigation? “We don’t see it,” snorted Mulligan to my question. It sounds great in theory, but his well data show that in practice, converting center pivots from sprinklers to dripping hoses doesn’t slow the speed of the Ogallala’s depletion. Instead, farmers just run their new drip systems longer so as to pull out the same volume of water, resulting in the same net drawdown. The hard fact is that there just isn’t any way to save an aquifer whose natural recharge is one-half to one inch per year, when it is being drawn down a foot or more per year. Ironically, the single biggest benefit of drip irrigation to farmers isn’t delaying the Ogallala’s death but ensuring it, by allowing access to its last remaining dregs.236 These wells are the final straws into a doomed giant once thought to be invincible.
Oil and Water Truly Don’t Mix
Everyone knows that it takes water to get food. Less obvious is how much energy it takes to get water (for pumping, moving, purifying, and so on). And hardly anyone grasps how much water is needed to get energy. But like hopeless lovers, water and energy are inextricably intertwined. Pressure on water resources, therefore, is intimately linked to pressures on coal, oil, and natural gas resources. Except for wind and certain forms of solar power, even renewable energy sources demand a lot of water.
Power plants—regardless of whether they run on coal, natural gas, uranium, biomass, garbage, or whatever—use water in at least two important ways: to make steam to turn a turbine and thus generate electricity; and to get rid of excess heat. The single greatest demand for water in the energy sector today is for the cooling of power plants. Over half of all water withdrawals in the United States alone, slightly more than for irrigating crops, are used for this purpose. That’s a half-billion acre-feet of water per year (enough to flood the entire country ankle-deep in water) to cool off our power plants. In some parts of Europe the percentage of water withdrawn for energy production is even higher.237
The total amount of water n
eeded depends greatly on the fuel used, on plant design, whether the water is recycled, the type of cooling apparatus, and so on. But in all cases the volume of water needed to operate the power plant is large, even greater than the volume of fuel. This is why plants are sited next to water bodies or perched over large aquifers. It’s not uncommon to find a coal-fired power plant on a riverbank hundreds of miles from the nearest coal mine: It is cheaper to carry the coal to the water, rather than the other way around. The Three Mile Island nuclear power plant, site of the 1979 accident described in the previous chapter, really is on an island, stuck out in the middle of the Susquehanna River.
Power plants bite into water supply by reducing both its quality and its quantity. Water recycled back into a river is hotter than the water withdrawn, sometimes by as much 25°C.238 For plants located on large bodies of water like the ocean, this doesn’t introduce significant environmental harm. Putting hot water into a river or lake, however, degrades aquatic ecosystems for many reasons. Warm water holds less dissolved oxygen, slows the swimming speed of fish, and interferes with their reproduction. Desirable cool-water species like trout and smallmouth bass are replaced by warm-water species like carp.
The second problem is water consumption, meaning irrevocable water loss. Most power plants use “wet” cooling towers—or even open ponds—to deliberately evaporate water into the atmosphere, providing cooling in the same way that evaporating sweat cools your skin. Evaporation losses from power plants are much smaller than the total withdrawal but are still significant in water-stressed areas. In very dry places, it becomes increasingly difficult to guarantee enough water for cooling purposes at all.
The World in 2050: Four Forces Shaping Civilization's Northern Future Page 12
