The World in 2050: Four Forces Shaping Civilization's Northern Future - Laurence C. Smith (2010)
Part I. THE PUSH
Chapter 4. California Browning, Shanghai Drowning
“Behold, he withholdeth the waters, and they dry up: also he sendeth them out, and they overturn the earth.”
In January 2008, the U.S. state of Iowa was on the front pages of newspapers all around the world. Ninety-four thousand voters of the Iowa Democratic Party had just propelled Barack Obama—a freshman Illinois senator who was virtually unknown just two years earlier—over the longtime national front-runner, Senator Hillary Rodham Clinton of New York. The Iowa caucuses are the first major electoral event in the U.S. presidential race and are widely believed to influence its outcome. Iowa’s voters had delivered a stunning upset and the opening salvo of one of the most exciting and protracted primary battles in U.S. electoral history. Little did they know that only five months later, their state would be on the front pages of newspapers around the world once again.
Within weeks after the political campaigns had left for other battles in other states, the snow started to fall. Two big storms dumped more than three feet of it around the little town of Oskaloosa. By March, Iowa had tied its third-highest monthly snowfall total in 121 years of record keeping. Then came the rain. April’s statewide average was the second-highest in 136 years. Twelve inches deluged the town of Fayette, obliterating its previous record of eight inches set back in 1909.181 Snowmelt and water ran everywhere, flooding cornfields and swelling streams and rivers. On May 25, a category F5 tornado—the strongest category of tornado and Iowa’s first F5 in forty years—leveled a forty-mile swath through tiny Parkersburg, killing eight people, destroying hundreds of homes, and narrowly missing populous Cedar Falls. President George W. Bush declared four counties federal disaster areas and the Federal Emergency Management Agency (FEMA) dispatched thirty-nine relief workers to the state.182 Forty-eight other tornados followed in the month of June, killing four Boy Scouts and raising the state’s tornado fatalities to its highest since 1968.
Then things got nasty. The wettest fifteen days in Iowa history began on May 29. Global food prices soared as farm fields in America’s top state producer of corn and soybeans melted away in the rain. In Cedar Rapids, thirteen hundred city blocks were inundated when the Cedar River leapt its banks and climbed eleven feet higher than had ever happened in the city’s 159-year existence. In Iowa City, parts of the University of Iowa campus were underwater. When I arrived in mid-July the university’s magnificent arts buildings and museum were trashed. Cedar Rapids was piled high with gutted wood, dead cars, and molding drywall. A train dangled crazily from a crushed bridge into the river. The little farming town of Oakville was simply wiped off the map—its former green fields cratered or buried in sand by the flood. There was nothing left but wrecked homes and fields, with plumes of black smoke rising from piles of burning wreckage.
By August, eighty-five of Iowa’s ninety-nine counties had been declared federal disasters. FEMA’s response team had grown from thirty-nine to fifteen hundred. Two million acres of the world’s finest farmland had lost twenty tons or more of topsoil per acre; six hundred thousand acres of bottomland were simply scoured away. 183 The statewide damage estimates had swelled to $10 billion—roughly $3,500 for every man, woman, and child in Iowa—and would later go even higher. By 2009 damage estimates to the University of Iowa alone were approaching one billion dollars.184 Forty thousand Iowans—almost half the number of voters who in January helped send Barack Obama to the White House—had been displaced from their homes.
Meanwhile, six states and eighteen hundred miles to the west, a very different water-related disaster was unfolding. On June 4, 2008—right in the middle of those wettest fifteen days of Iowa history—Governor Arnold Schwarzenegger strode to a podium in Sacramento to declare an official state of drought in California, the largest total producer of agricultural products in the United States.
Conditions in the Golden State had deteriorated rapidly in an already dry decade. The year before, rainfall in Southern California had been 80% below average. Statewide snowpack and rainfall levels were so low that farmers had begun abandoning their crops. By October, the extreme dryness had fueled a series of vicious wildfires, killing ten people and forcing almost a million more to evacuate. Thousands of homes were destroyed. 185 By May 2008, northern California was also suffering. In many areas its rainfall, too, fell 80% below normal. Flows in the Sacramento and San Joaquin rivers were critically low. Reservoir levels were down across the state, and Lake Oroville, a key supplier to California’s massive State Water Project, was half gone. More than a hundred thousand acres in California’s sprawling Central Valley—the very heart of the state’s gigantic agricultural engine—went unplanted.
Schwarzenegger issued an executive order setting into motion water-transfers, conservation programs, and other measures to combat the crisis,186 but the drought deepened. Water levels fell further and more fires burned. Eight months later, in February 2009, he proclaimed a state of emergency. Citing “conditions of extreme peril to the safety of persons and property” and “widespread harm to people, businesses, property, communities, wildlife, and recreation,”187 he ordered even more draconian measures to be taken. Experts were predicting that field fallowing would rise from one hundred thousand to eight hundred thousand acres—meaning that nearly 20% of the Central Valley’s farmland would go unplanted.188 Suddenly, on top of a historic economic crisis from collapsed housing and global credit markets, California was bracing to lose another eighty thousand jobs and $3 billion in agricultural revenue from drought.
Iowa and California were not alone in their water-related crises. As Schwarzenegger mobilized California, the southeastern United States, which is usually moist, was also in historic drought, triggering a wave of outdoor-watering bans, withered crops, and unheard-of water battles between states like Georgia, Tennessee, and the Carolinas.189 Mexico had been in severe drought, with only limited relief, for fifteen years.190 Exceptional droughts were under way in Brazil, Argentina, western Africa, Australia, the Middle East, Turkey, and Ukraine.191 Drought emergencies were triggering food aid in Lesotho, Swaziland, Zimbabwe, Mauritania, and Moldova.192 By February 2009, precipitation was 70%-90% below normal in northern and western China, threatening 10% of the country’s entire cereal production. 193 That same month, extreme dryness primed “Black Saturday,” when six hundred blazes killed two hundred people in the worst Australian wildfires in history. By April, crop failures in Chattisgarh state drove fifteen hundred Indian farmers—unable to repay their debts without water—to commit suicide.194
Within days of the Iowa floods, heavy rains also struck eastern India and China, killing sixty-five people and displacing five hundred thousand in India. In China, floods in Guangdong and Guangxi Zhuang, Sansui City, and the Pearl River delta killed 176 and displaced 1.6 million. While America’s eyes were fixed on Sarah Palin, hydrologist Bob Brakenridge at Dartmouth was watching floods from space, using satellites to track them all over the world.195In the ten months between Barack Obama’s winning the Iowa caucuses on January 3, and the general election on November 4, Brakenridge documented 145 major floods carving destruction around the planet. As Barack Obama took down first Hillary Clinton and then John McCain, those rivers took down lives and property from Taiwan to Togo. They killed almost five thousand people and washed seventeen million more from their homes.
Our Most Necessary Resource
It’s hard to imagine anything humans need more than freshwater. If it were to all somehow vanish, the human race would be extinct in a matter of days. If it stopped flowing to our animals and fields, we would starve. If it became unclean, we would become sick or even die. Our societies need water in proper quantity, quality, and timing to preserve civilization as we know it. Too little, or at the wrong time of year, and our food dies off and industries fail. Too much, and our fields dissolve and people drown. For the past ten thousand years the very existence of permanent human settlements has depended upon having a consistent, dependable supply of usable water.
What does the future hold? Are we running low on water, as we must ultimately run low on oil? In the past fifty years we’ve doubled our irrigated cropland and tripled our water consumption to meet global food demand. In the next fifty, we must double food production again.196 Is there really enough water to pull that off?
In his book When the Rivers Run Dry environmental journalist Fred Pearce describes in vivid, firsthand detail the stark reality of impending water crises in more than thirty countries around the globe. We now withdraw so much water that many of our mightiest and most historic rivers—like the Nile, the Colorado, the Yellow, the Indus—have barely a trickle left to meet the sea.
The good news is that, unlike oil, which is ultimately finite, water is endlessly returned to us by the hydrologic cycle. Except for fossil groundwater, there is no such thing as “Peak Water” in the same sense as “Peak Oil.” It always comes back—somewhere—as rain or snow. It may be too much, or too little, or come at the wrong time, but it does come back. The bad news is that in addition to the aforementioned problems of too much, too little, or bad timing, our water sources can also become polluted. Finally, while it’s true that there is plenty of water circulating out there someplace, nearly all of it is useless to us.
The Russian hydrologist Igor Alexander Shiklomanov estimates that almost 97% of the world’s water is salty ocean, unfit for drinking or irrigation; 1% is salty groundwater, again useless. Of the 2.5% or so that is fresh, most would be salty if not for the glaciers of Antarctica, Greenland, and mountains that hold it up on land in the form of ice, rather than letting it run off into the ocean. Fresh groundwater holds about three-quarters of 1%. The minuscule remainder—about eight one-thousandths of 1%—is held in all the world’s lakes, wetlands, and rivers combined. Our atmosphere’s clouds, vapor, and rain hold even less, just one ten-thousandth of 1% of all water on Earth. 197
There are three points to be taken from Shiklomanov’s numbers. The first is that the most important sources of water for people and terrestrial ecosystems—rivers, lakes, and rain—are actually fleetingly rare forms of H2O. If all the water in the world was a thousand-dollar bill, these sources would amount to about eight cents. The second point is that relative to rivers, lakes, and rain, far larger volumes of freshwater are frozen up inside glaciers, or stored underground in aquifers. These, too, are critically important to humanity and will be discussed shortly.
The third point—and frankly one that is all too often neglected by policy makers and scientists alike—is that these numbers alone do not tell the whole story when it comes to human water supply. Recall that water, unlike oil, is a circulating resource. It recycles constantly through the hydrologic cycle, in infinite loops of rain, runoff, evaporation, and various storage compartments, like ice. From a practical standpoint the throughput of freshwater (or “flux”) is just as important as the absolute size of its various containers. The total volume of water held in rivers at any given instant is tiny, but it is replaced quickly, unlike, say, an ancient glacier or slowly oozing aquifer. A water droplet moves down a natural river in a few days, whereas the same droplet moving through glaciers, groundwater, and deep ocean currents could be stuck there for centuries to hundreds of thousands of years. This explains the seeming paradox that despite the world’s rivers’ instantaneous storage capacity of just two thousand cubic kilometers of water, we pull almost twice that amount from them every year.198
This is why rainfall and surface water, despite their diminutive holdings, are so critically important to land-based ecosystems and people. Their fast throughput is what makes them so valuable. But because their storage capacities are so tiny, we are vulnerable to the smallest of variations in that throughput. Unlike an ocean or glacier, the atmosphere and rivers have no meaningful storage capacity from which to draw water in dry times or hoard it in wet times. Therefore, terrestrial life is highly sensitive to floods and droughts, whereas marine life is generally not. Tuna have plenty of worries, but droughts are not one of them. Battling this vulnerability is a prime reason why we have built millions of dams, reservoirs, lakes, and ponds throughout the world. Yet even after all this massive engineering, we still have only enough of these artificial impoundments to store slightly less than two years’ water supply.199
The other big problem for humans, of course, is that this small bucket of fast-recycling river water is spread very unfairly around the planet. Canada, Alaska, Scandinavia, and Russia are veined with so many permanent streams, rivers, and lakes that most have never been named, whereas Saudi Arabia has no natural ones at all. Water-rich Norway has 82,000 cubic meters of renewable freshwater per person while Kenya has just 830.200 And to a very large degree, this unfair distribution of surface water is created by the pattern of the global atmospheric circulation itself.
Rainmaker, Land Baker
Just a hundred steps into the rain forest my head was thudding, my shirt drenched, and I couldn’t breathe. It wasn’t claustrophobia—although I couldn’t see well through the green gloom of filtered canopy light—but the wet, steaming heat. It was like inhaling vapors over a teakettle. Something went soft under my foot—I had unwittingly crushed an exotic caterpillar the length of my hand. I excused myself from the group and walked gasping back toward the boat, but was intercepted by an aboriginal man. He was selling tiny clay couples with enormous genitalia, eternally frozen in joyous copulation. Back on the boat, a hot breeze blew down the Amazon River but my skin dripped even faster. The air was totally saturated. I couldn’t wait to get back to my air-conditioned hotel room in Manaus.
I must have caught the Amazon on a bad day. Most living things love tropical rain forests. Their wide green sash—plain on any world map, roughly encircling the equator—is bursting with life and contains the vast majority of species, known and as yet undiscovered, on Earth. Rain forests grow there thanks to the condensate downpours dumped by the moist, rising air masses of the Intertropical Convergence Zone (ITCZ). This band of clouds and rain follows the Sun, circling nearly directly overhead, as it sizzles the equatorial oceans and landmasses to evaporate huge quantities of water vapor. The vapor rises, cools, and condenses, deluging the tropics with rain and triggering the Asian and African monsoons as the ITCZ drifts back and forth across the equator each year, endlessly chasing the seasonal march of the Sun. Billions of living things hang on the strength and reliability of these annual rainfall patterns, including us.
To the north and south, straddling the lush equatorial belt and monsoonal areas like the dried-out bun halves of a veggie sandwich, are two huge drought-stricken bands of drylands and deserts. The Sahara, Arabian, Australian, Kalahari, and Sonoran are all found here, huddled at roughly 30º N and S latitude. While not lifeless, these zones are decidedly stark compared with their green equatorial neighbor. They mark the killing fields of the moist ITCZ air masses. Emptied of their rain holdings, the air masses drift north or south before tumbling earthward again, baking the land with crushing dry heat, pressed downward by the weight of still more air falling from above. Like the perpetual circuit of rising and falling wax in a Lava lamp, this sinking air closes the convection loop, flowing from both hemispheres back toward the equator in the form of trade winds. From there, the Sun’s rays will moisten and lift the air once again, repeating the cycle. This overall pattern of atmospheric circulation, called the Hadley Cell, is one of the most powerful shapers of climate and ecosystems on Earth.
Despite the harsh aridity, billions of people live in or around those twin subtropical blast zones of sinking dry air, which contain some of our fastest-growing human populations. Pressing hard into the Sahara’s southern flank are nearly eighty million people of Africa’s Sahel, a population projected to reach two hundred million by 2050.201 North of the Sahara are the large populations of northern Africa and Mediterranean Europe. Australian cities cling to the coastline of their dusty continent, leaving the continent’s vast desert interior mostly uninhabited. But the parched Middle East, southern Africa, and western Pakistan are heavily populated and have some of the youngest, fastest-growing populations in the world.
Phoenix and Las Vegas—two briskly growing cities in the arid southwestern United States—lie in the middle of a Hadley Cell desert. Nineteen million people can survive in Southern California only because there are a thousand miles of pipelines, tunnels, and canals bringing water to them from someplace else. It comes from the Sacramento-San Joaquin Delta and Owens Valley to the north, and from the Colorado River to the east, far across the Mojave Desert. They enjoy green lawns, burbling fountains, and swimming pools in a place where rainfall averages less than fifteen inches per year. A second canal202 from the Colorado pumps water up nearly three thousand feet in elevation and 330 miles east to Phoenix and Tucson, prompting Robert Glennon, author of Water Follies, to observe that we literally move water “uphill to wealth and power.”203 Without this infrastructure and the energy to run it, Arizonans’ water supply would more closely resemble that of Palestinians: fifteen dubious gallons a day haggled from the back of a water trafficker’s truck.
Which Is Worse?
Even if there were no climate change, the world would still be facing declining per capita water supply because of our growing economy and population. In general, more people means more water demand. Even if we could freeze population growth, advancing modernization means more meat, finished goods, and energy, all of which raise per capita water consumption.204 Contrary to common perception, population growth and industrialization thus represent an even bigger challenge to the global water supply than does climate change.
Policy wonks and water managers have long sensed this. But hydrologist Charlie Vörösmarty blew it wide open in 2000 when he and his colleagues Pamela Green, Joe Salisbury, and Richard Lammers at the University of New Hampshire compared climate and hydrologic models with long-term population and water-consumption trends.205 As part of the study, they published three brightly colored maps of projected water demand for 2025. I make my students stare at these maps at least once in my introductory course lectures at UCLA.
One of the maps is quite scary-looking and captures the combined effects of both climate and population trends on human water-supply stress. Most of the world is colored red (indicating less water availability than today) with a few places colored blue (more water availability, mostly in Russia and Canada) and even fewer in green (meaning little or no change). This fearsome red map suggests that by the year 2025 much of humanity’s water supply will be worse off, either from population growth, or climate change, or both.
The other two maps separate out the effects of population and climate change. The population-only map is even scarier than the combined map. Nearly all the world is bathed in red, with blue colors even rarer than before. Compared to it, the climate-only map seems almost benign, with roughly equal proportions of blue and red tones and even more in green. In other words, climate changes are expected to both harm and help water availability in different parts of the world, whereas population and economic growth harm it nearly everywhere.206 So even if our climate-change problems could somehow disappear tomorrow (and they won’t), we would still face enormous challenges to water supply in some of the hottest, most crowded places on Earth.
It’s hard to imagine the world behind those red maps. To most people—especially living in cities—clean water is like oil and electricity: one of those things upon which they depend mightily yet give barely a passing thought. In my own city of Los Angeles, everyone will gladly pay a hundred dollars a month for cable television, yet would roar in protest if forced to pay that much for life’s elixir piped directly into their homes. When Governor Schwarzenegger declared a state of drought emergency, I studied my water bill closely for the first time in my life. For two months of clean drinking water, snared from faraway sources and delivered to my house by one of the world’s most expensive and elaborate engineering schemes, I was charged $20.67. I spend more on postage stamps.
If only everyone could indulge such ignorant bliss. While eight in ten people have access to some sort of improved water source,207 this globally averaged number masks some wild geographic discrepancies. Some countries, like Canada, Japan, and Estonia, provide clean water to all of their citizens. Others, especially in Africa, do so for under half. The worst water poverty is suffered by Ethiopians, Somalis, Afghanis, Papua New Guineans, Cambodians, Chadians, Equatorial Guineans, and Mozambicans.208 Even their statistics hide the most glaring divide—between cities and rural areas. Eight in ten urban Ethiopians have some form of improved water whereas just one in ten rural Ethiopians do.
As we saw in Chapter 3, cities empower efficient channeling of natural resources to people. It is far more economical to lay water pipes and sewerage in a densely populated area than to spread them across the countryside. For much of the world, even sewers are a luxury. Unbelievably, four in ten of us don’t even have a simple pit latrine. Small wonder that waterborne diseases kill even more people than our raging epidemic of HIV/AIDS. As Jamie Bartram of the United Nations World Health Organization writes:
Far more people endure the largely preventable effects of poor sanitation and water supply than are affected by war, terrorism, and weapons of mass destruction combined. Yet those other issues capture the public and political imagination—and public resources—in a way that water and sanitation issues do not. Why? Perhaps in part because most people who read articles such as this find it hard to imagine defecating daily in plastic bags, buckets, open pits, agricultural fields, and public areas for want of a private hygienic alternative, as do some 2.6 billion people. Or perhaps they cannot relate to the everyday life of the 1.1 billion people without access to even a protected well or spring within reasonable walking distance of their homes.209
Most experts agree that getting clean water to the world’s poorest people is largely a matter of money. According to the United Nations, the price tag for everyone to have safe, clean drinking water would be about $30 billion per year. But in the poorest countries, building water treatment plants and a network of pipes to move it is still prohibitively expensive, especially for rural areas. Well-intentioned foreign aid often fails to leave the cities of ruling elites. And while small, inexpensive water treatment technologies like ultraviolet purification hold promise, microprojects have failed to attract much interest from the big lenders. Water expert Peter Gleick, cofounder and president of the Pacific Institute, likes to point out that the World Bank and International Monetary Fund know how to spend a billion dollars in one place (on a big dam project, for example) but not how to spend a thousand dollars in a million places. But all too often, a thousand-dollar solution is what’s needed most. Getting clean water to people living in our most impoverished places remains an enormous challenge, with no clear solution on the horizon.
Another trend is further clouding the picture. Multinational corporations are increasingly moving to privatize and consolidate water supplies. Over the past decade, at least three—Suez, Veolia Environmental Services (formerly Vivendi), and Thames Water—have expanded into for-profit water delivery ventures all over the developing world. In early 2009 Germany’s industrial giant Siemens paid nearly $1 billion for U.S. Filter, the leading supplier of water treatment products and services in North America. Multinational giants like General Electric and Dow Chemical are also jumping into the water business, alongside other companies you’ve never heard of, like Nalco, ITT, and Danaher Corporation.
The benefit of this water-privatization frenzy is the expansion of modern water treatment and distribution facilities into impoverished places that desperately need them. However, these are for-profit companies, not public municipalities. In return for the new infrastructure, they must charge fees for the water in order to recoup building costs and generate profits for their shareholders. This is a familiar transaction in the developed world, where people are accustomed to paying for water, but is a radical shift in poor countries where municipal water supply—to the extent that it is available—is often free.
Control of life’s most essential natural resource by overseas multinational corporations is an abomination to people like Maude Barlow, author of Blue Gold and Blue Covenant.210 These books point out that to the poorest of the poor, even a few cents for water is unaffordable, forcing them to drink from polluted streams and ditches, fall sick, and die. Extrapolating the current globalization trend into the future, Barlow imagines the following in Blue Covenant:
A powerful corporate water cartel has emerged to seize control of every aspect of water for its own profit. Corporations deliver drinking water and take away wastewater; corporations put massive amounts of water in plastic bottles and sell it to us at exorbitant prices; corporations are building sophisticated new technologies to recycle our dirty water and sell it back to us; corporations extract and move water by huge pipelines from watersheds and aquifers to sell to big cities and industries; corporations buy, store, and trade water on the open market, like running shoes. Most importantly, corporations want governments to deregulate the water sector and allow the market to set water policy. Every day, they get closer to that goal.
Opponents of multinational companies are a passionate group, and especially when it comes to water. They protest that water privatization has become a key objective of the World Bank, and even of regional lenders like the African Development Bank and Asian Development Bank, with full buy-in from the United Nations and World Trade Organization. They accuse the World Water Council—purportedly an ideologically neutral platform to promote “conservation, protection, development, planning, management, and use of water in all its dimensions on an environmentally sustainable basis for the benefit of all life on Earth”211—as in fact being a subversive global champion of water privatization and business corporations. They organize resistance movements and sit-ins, losing a fight with Nestlé over a Poland Spring bottling plant in Michigan, winning another against Coca-Cola at Plachimada, India; and even street riots to force Bechtel out of Bolivia.212
Surveying the debate coolly from arm’s length, one can appreciate the benefits of the private-sector model. If countries cannot or will not deliver clean water to their citizens who desperately need it, and neither will the World Bank, then why not let private capital have a go? On the other hand, something does feel creepy about transferring control of life’s most basic requirement—clean drinking water—from local to overseas control, to corporations whose fiduciary responsibility lies first and foremost with their shareholders. Paying for water works fine in the developed world, but where people earn a dollar per day? Is water property, or human right? This battle continues on fronts all over the world, with no clear best path forward.
World population will grow by 50% in the next forty years, nearly all of it in the developing world and mostly in places that are already water-stressed now. This new population will also be wealthier and eat more meat, thus requiring higher per capita food production than today. To meet this projected demand for food and feed, we must double our crop production by 2050. Finding enough freshwater to support this, plus more industry, plus billions of new apartments, all while keeping the water clean as it cycles endlessly between our kidneys and the environment, is very likely the greatest challenge of our century.
The Information Revolution
Breakfasts at high-powered NASA meetings in Washington, D.C., were much less glamorous than I’d hoped. Rather than sampling astronaut food in a gleaming high-tech boardroom, I was hunched in a bland carpeted hallway at the Marriott, poking a half-empty platter of stale bagels. But I didn’t mind. I grabbed the last poppyseed and a cup of coffee and ducked into the cramped meeting room. My old grad-school roommate Doug Alsdorf, now a professor at Ohio State, was bellowing at us to take our seats. I found one and sat quickly. One of the smartest men I have ever known, radar engineer Ernesto Rodriguez from NASA’s Jet Propulsion Laboratory, was preparing to give us another update on our half-billion-dollar idea.
The water crisis is about more than failing crops and unsanitary conditions. It is also about information—or more precisely, the lack of it—for effective water management. Water is constantly on the move, but unbelievably, we have hardly any idea of where, when, or how much we have at any given moment. Our knowledge of Earth’s hydrology is extraordinarily data-poor. Other than large rivers, few streams are measured. Outside the United States and Europe, the vast majority of water bodies receive no hydrologic monitoring whatsoever. We have basically zero information for small lakes, cattle ponds, and wetlands. Even the water levels behind dams, while monitored by their operators, are seldom released to the broader public in many countries.
Because of this information gap, millions of people have no idea whether next week will bring lower water levels in their river or lake, or a raging flood. Emergency workers don’t know when a flood has peaked or how high it will go. Along many rivers even the weather isn’t a reliable predictor because upstream reservoirs release water at the command of dam operators, not rainstorms. In a complete reversal of their preexisting natural state, many of today’s rivers shrink, not swell, as they move downstream. In fits and starts, a gauntlet of diversions and dams sips them to death.
Since construction of the High Aswan Dam almost all flow in the Nile River is now either diverted for irrigation or evaporates away behind reservoirs. 213 Dams along Africa’s Volta River system can hold back or release more than four years’ worth of its total river flow. Water passage through the Euphrates-Tigris in the Middle East, the Mae Khlong in Thailand, the Río Negro in Argentina, and the Colorado in North America is similarly controlled. But hydrologic data are seldom released. Many countries even classify them, so their downstream neighbors can’t tell if they are complying with international water-sharing agreements.214
These are the reasons why our group of scientists and engineers were in that Washington, D.C., hotel room, and in other meeting rooms like it in Rome, San Francisco, Barcelona, Paris, Orlando, San Diego, Columbus, and Lisbon. There are now over five hundred of us in thirty-two countries, working on a bold new idea to globalize information about water resources, by measuring it everywhere and all the time, from space. The technology to do it is a satellite called a wide-swath altimeter. It uses a remarkable radar technology that Ernesto Rodriguez invented, called a “Ka-band radar interferometer” or KaRIn (named adorably after Ernesto’s wife). We’re going to put KaRIn into space, mounted on a satellite called SWOT.215
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.228In 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 needed 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.
In the first study of its kind, Martin Pasqualetti, a professor in the School of Geographical Sciences and Urban Planning at Arizona State University,239 scrutinized how much water consumption (i.e., evaporation) Arizona’s different energy technologies require in order to produce one megawatt-hour of electricity. What he found may surprise you:
Water Losses Embedded in Arizona Electricity Generation
From Pasqualetti’s data we learn that the water consumption of energy production is not only large, but varies tremendously depending on the type of energy being used. For example, a nuclear power plant evaporates about 785 gallons of water to generate one megawatt-hour of electricity, whereas natural gas power plants evaporate considerably less (especially modern combined-cycle plants, which evaporate about 195 gallons per megawatt-hour). This means that an average house in Phoenix, using twenty megawatt-hours per year, will unknowingly evaporate nearly 16,000 gallons of water if its electricity comes from a nuclear power plant, but only about 3,900 gallons if it comes from a combined-cycle natural gas plant. More virtual water.
To put that number into perspective, 15,000 gallons is roughly what a typical Phoenix household with irrigated landscaping uses in two weeks. So this “embedded” water is not an enormous amount, but still significant in such a dry place. But the big surprise here is that in terms of electricity generation, hydropower, of all things, is the worst water waster,240 followed by concentrated solar thermal (CSP) technology, then nuclear. Arizona does not grow biofuel crops, but other studies show biofuels are even worse than hydro in terms of water consumption.241 Thus biofuels, hydropower, and nuclear energy, while hailed for being carbon-neutral (or nearly so), are worse even than coal when it comes to water consumption. Of the renewables, only wind and solar photovoltaics are truly benign—something, Pasqualetti points out, that would make solar photovoltaics more cost-competitive if the price of the saved water was taken into account.
The water-energy nexus works both ways. Examined in the opposite direction, energy is needed at every step along the way to deliver clean water to a house. Take again, for example, our typical Phoenix home, which consumes about an acre-foot of water per year. It requires two megawatt-hours of electricity—roughly 10% of the home’s total energy use—to pump that acre-foot uphill from the Colorado River some two hundred miles away, purify it, and pressurize it locally. But those megawatt-hours never appear on any electric bill; they are embedded within the water bill itself. Remarkably, almost all the cost of providing drinking water to Phoenix households is for the energy embodied within it, not for the water.
“Indeed,” says Pasqualetti, “water and energy are married to one another. Water is needed in electrical generating stations if they are to run efficiently. Energy, on the other hand, is needed to provide our houses with safe drinking water. How much of each commodity is needed to provide the other is something not well appreciated by the public.”242
It is something not well appreciated by politicians and planners either. Instead of recognizing this marriage between energy and water, their respective planning and regulatory agencies are almost always totally separate entities. “Energy analysts have typically ignored the water requirements of their proposed measures to meet stated energy security goals. Water analysts have typically ignored the energy requirements to meet stated water goals,” concluded a recent Oak Ridge National Laboratory report.243 Historically we have gotten away with this thanks to cheap water, cheap energy, or both. That cushion will continue to narrow as supplies of both tighten out to 2050.
One of the most widely anticipated outcomes of climate change is that the Hadley Cell circulation will weaken slightly and expand. This appears not only in a broad range of climate model projections for the future, but also from historical data extending three decades into the past.244 The effect of this is the spawning of more clouds and rain in the tropics, but even drier conditions and a poleward expansion of the two desert blast zones straddling both hips of the equator. Precipitation futures are notoriously difficult to project, but this is one of those things about which all the climate models agree. Put simply, many of the world’s wet places will become even wetter, and its dry places even drier.
Rainfall will increase around the equator, but decrease across the Mediterranean, Middle East, southwestern North America, and other dry zones. Rivers will run fuller in some places and lower in others. One highly regarded assessment tells us to get ready for 10%-40% runoff increases in eastern equatorial Africa, South America’s La Plata Basin, and high-latitude North America and Eurasia, but 10%-30% runoff declines in southern Africa, southern Europe, the Middle East, and western North America by the year 2050.245 Through the language of statistics, these models are telling us to brace for more floods and droughts like the ones in Iowa and California.
The Great Twenty-first-Century Drought?
Part of the explanation for the many floods and droughts that happened around the world in 2008 was that it was a La Niña year, meaning that sea surface temperatures (SSTs) in the eastern half of the tropical Pacific Ocean cooled off. This triggered, among other things, dry conditions over California, contributing to its ongoing drought (her counterpart, El Niño, is associated with warm SSTs and wetter conditions there). Through connections between the sloshing ocean and the atmosphere, this “Little Girl” had impacts on human water supply that reverberated worldwide.
My UCLA colleague Glen MacDonald, an expert in the study of prehistoric climate change, is deeply concerned that something like the 2008 La Niña could happen again—but persisting for decades rather than months. In fact, MacDonald and his students believe the American Southwest, in particular, could be struck by a drought worse than anything ever seen in modern times. From shrunken tree-rings and other prehistoric natural archives, they have assembled a growing body of evidence that the region suffered at least two extended “Perfect Droughts” (coined by MacDonald to describe periods when Southern California, northern California, and the upper Colorado River Basin all experienced drought simultaneously) during medieval times.246 These Perfect Droughts were as bad as or worse than the Dust Bowl but lasted much longer, persisting as long as five to seven decades (the Dust Bowl lasted barely one). These prehistoric data tell us that this heavily populated region is capable of experiencing droughts far worse than anything experienced since the first European explorers arrived.
One reason for these massive prehistoric droughts was that between seven hundred and nine hundred years ago temperatures rose. The increase was similar to what we are beginning to see now but not so high as what climate models are projecting by 2050. The reason for the medieval temperature rise (fewer volcanic eruptions plus higher solar brightness) was different from what’s happening today, but it nonetheless provides us with a glimpse of how our planet might respond to greenhouse warming.247
Not only did the medieval climate warming increase the drying of soils directly, it may also have altered an important circulation pattern in the Pacific Ocean, by shifting relatively cool water masses off the western coast of North America for many decades at a time (this would be a prolonged negative phase of the so-called “Pacific Decadal Oscillation,” an El Niño- like oscillation in the northern Pacific that currently vacillates over a 20-30-year time scale). This likely created pressure systems driving rain-bearing storm tracks north, rather than south, across the western United States, triggering drought conditions in the American Southwest. Should the projected rise in air temperatures cause the Pacific circulation to behave like this again, the prolonged medieval megadroughts could return. Similar connections between shifting sea-surface temperatures and geographic rainfall patterns over land exist for the Atlantic and Indian oceans as well.
MacDonald points out that by the time Schwarzenegger declared a state of emergency in 2009, most of the southwestern United States was actually in its eighth year of drought, not third. “Arguably, we are now into the great Twenty-first Century Drought in western North America,” he mused to me. “Could we be in transition to a new climate state? Absolutely. Should we be worried? Absolutely.” His concerns are echoed by Richard Seager at Columbia University’s Lamont-Doherty Earth Observatory. In a widely read Science article,248 Seager and his colleagues showed consensus among sixteen climate models that projected greenhouse warming will drive the American Southwest toward a serious and sustained baking. Their result, of course, is dependent on the group of models analyzed, and the simulation is imperfect because today’s coarse-scale climate models don’t represent mountainous areas very well (e.g., the Rockies, which produce most of the region’s snowpack water). But if these model projections prove correct, then the drought conditions associated with the brief American Dust Bowl could conceivably become the region’s new climate within years to decades.
“Stationarity Is Dead,” announced another Science article in 2008, sending a cold shiver through the hearts of actuaries around the world.249 A hydrology dream team of Chris Milly, Bob Hirsch, Dennis Lettenmaier, Julio Betancourt, and others had just told them that the most fundamental assumption of their job description—reliable statistics—was starting to come apart.
Stationarity—the notion that natural phenomena fluctuate within a fixed envelope of uncertainty—is a bedrock principle of risk assessment. Stationarity makes the insurance industry work. It informs the engineering of our bridges, skyscrapers, and other critical infrastructure. It guides the planning and building codes in places prone to fires, flooding, hurricanes, and earthquakes.
Take river floods, for example. By continuously measuring water levels in a river for, say, twenty years, we can then use the stationarity assumption to calculate the statistical probability of rarer events, e.g., the “fifty-year flood,” “hundred-year flood,” “five-hundred-year flood,” and so on. This practice, while creating enormous misunderstanding with the public,250 has also made us safer. Hard statistics, rather than the whims of developers or mayors, are used to design bridges and for zoning. But flood prediction, and most other forms of natural-hazard risk assessment, rest on the core assumption that the statistics of past behavior will also apply in the future. That’s stationarity. Without it, all those risk calculations go straight out the window.
A growing body of research is showing that our old statistics are starting to break down. Climate change is not the sole culprit. Urbanization, changing agricultural practices, and quasi-regular climate oscillations like El Niño all influence the statistical probabilities of flooding. However, the dream team’s paper and others like it251 tell us that climate change is fundamentally altering the statistics of extreme floods and droughts, two things of enormous importance to humans. “In view of the magnitude and ubiquity of the hydroclimatic change apparently now under way,” they wrote, “we assert that stationarity is dead and should no longer serve as a central, default assumption in water-resource risk assessment and planning. Finding a suitable successor is crucial for human adaptation to changing climate.”252
Unfortunately, we have no good replacement for stationary statistics yet, certainly nothing that works as well as they once did. Moreover, there has been hardly any basic research done in this area since the 1970s. We can’t just invent a completely new branch of mathematics and train a new generation of water experts in it overnight. “Water resources research has been allowed to slide into oblivion over the past thirty years,” Lettenmaier growled later in a separate editorial. “Certainly the profession has been slow to acknowledge these changes and acknowledge that fundamentally new approaches will be required to address them.”253 So even as we’re beginning to grasp the enormity of this problem, we presently have no clear replacement for our old way of doing things. Until we find one, risks will be harder to predict and to price. We can expect insurance companies to react accordingly. In 2010, after failing to win a nearly 50% rate increase from state regulators, Florida’s largest insurance company abruptly canceled 125,000 homeowner policies in the state’s hurricane-prone coastal regions, saying the recent series of devastating hurricanes had rendered its business model unworkable. 254 Get ready for higher premiums, uninsurable properties, and failed or overbuilt bridges.
Changing drought and flood statistics are not the only way that rising greenhouse gases harm our water supply. All of our reservoirs, holding tanks, ponds, and other storage containers are trifling compared to the capacity of snowpacks and glaciers. These are free-of-charge water storehouses, and humanity depends upon them mightily.
Snow and ice hoard huge amounts of freshwater on land, then release it in perfect time for the growing season. They do this by bulking up in winter, then melting back in spring and summer. They are the world’s hugest water-management system and, unlike a dam reservoir, displace no one and cost nothing. Glaciers (and permanent, year-round snowpacks) are especially valuable because they outlast the summer. This means they can hoard extra water in cool, wet summers, but give it back in hot, dry summers, by melting deeply into previous years’ accumulations. Put simply, glaciers sock away water in good years when farmers need it least, and release water in bad years when farmers need it most. Glaciologists call these “positive mass-balance” and “negative mass-balance” years, respectively, and they are a gift to humanity. Glaciers keep the rivers full when all else is dry. They are the ultimate sunny-day fund.
If you read the news, then you already know that many of the world’s glaciers are beating a hasty retreat, whether through warmer temperatures, less precipitation, or both. Ohio State University’s glaciologist power-couple Lonnie Thompson and Ellen Mosley-Thompson have been photographing the deaths of their various study glaciers since the 1970s. Some of these are even wasting away at their summits, which is a death knell for a glacier. There are ski resorts in the Alps trying to save theirs by covering them with reflective blankets. Most glaciologists expect that by 2030, Montana’s Glacier National Park will have no glaciers left at all.
Seasonal snowpack, which does not survive the summer, cannot carry forward water storage from year to year like glaciers do, but it is also a critically important storage container. It creates a badly needed time-delay, releasing water when farmers need it the most. By holding back winter precipitation in the form of snow, the retained water flows downstream to farmers later, in the heat of the growing season. Without this huge, free storage container, this water would run off uselessly to the ocean in winter, long before growing season. Rising air temperatures harm this benefit, both by increasing the prevalence of winter rain (which is not retained) and by shifting the melt season to earlier in the spring. Because the growing season is determined not only by temperature but also the length of daylight, farmers are not necessarily able to adapt by planting sooner. By late summer, when the water is needed most, the snowpack is long gone.
This seasonal shift to earlier snowmelt runoff portends big problems for the North American West and other places that rely on winter snowpack to sustain agriculture through long, dry summers. California’s Central Valley—the biggest agricultural producer in the United States—depends heavily on Sierra snowmelt, for example. But the long-term projection for health of the western U.S. snowpack is not good. It has already diminished in spring, despite overall increases in winter precipitation, in many places.255 By late 2008, Tim Barnett at the Scripps Institute of Oceanography and eleven other scientists had definitively linked this phenomenon to human-caused climate warming. This is not good news, they wrote in Science, warning of “a coming crisis in water supply for the western United States” and “water shortages, lack of storage capability to meet seasonally changing river flow, transfers of water from agriculture to urban uses, and other critical impacts.”256
High-profile research like this does not go unnoticed by policy makers. One response is to build more reservoirs, canals, and other engineering schemes to store and move water. China is now planning fifty-nine new reservoirs in its western Xinjiang province to retain water from glacier-fed rivers. In 2009, U.S. Interior Secretary Ken Salazar announced $1 billion in new water projects across the American West, with over a quarter-billion going to California alone.257
Thus begins our new technological race—to adapt to a shrinking water storage capacity, once provided for free by snow and ice. But it is important to understand that no amount of engineering can replace that storage. Think back to I. A. Shiklomanov (p. 86), his huge container of ice, and trifling container of surface water. Even if we quadrupled the world’s reservoirs, they wouldn’t come remotely close to replacement. And even if they did, we’d still end up with less water: Unlike snow and ice, water evaporates like crazy from open reservoirs.
We can’t hold it all back. More of the world’s water is leaving the mountains to run to the sea.
Into the Sea
It’s abnormal to be thinking about melting glaciers when standing on a nice sunny beach during holiday break. But this was no ordinary beach and no ordinary holiday. It was Christmas 2005, and I and other members of the Smith family were staring dumbly at the bones of what had once been my aunt and uncle’s house, a dozen blocks inland from the Mississippi coast. With the ease of a kid blowing foam across a cup of hot chocolate, Hurricane Katrina had thrown a wall of water—a storm surge—right through their lovely Biloxi neighborhood.
The place was a deserted war zone. Houses smashed to splinters, cars crushed and tossed into swimming pools. Nearer the beach, there were no house bones at all, just smooth rectangles of white concrete, scrubbed and gleaming to show where million-dollar homes had once stood. It was four months since the hurricane but the place was abandoned. No one was hauling away debris, no sound of hammering nails. All was silent except for the songbirds, cheeping and squabbling amid the wreckage. To them it was just another beautiful day on the American Gulf Coast.
In devastated New Orleans, ninety miles to the west, we saw a similar abandonment of entire neighborhoods. There were blocks and blocks of leaning houses, trashed and dark except for the colorful graffiti of rescue-worker symbols. The hieroglyphs recorded each house’s history in spray paint—the date searched, any noted hazards, whether any human bodies had been found. Living in one home was a pack of feral dogs.
So that is why, while standing on a gorgeous sunny beach, I was thinking about glaciers. In smashing my uncle’s former home, Hurricane Katrina had made the dry statistics of my field feel real—on a personal, visceral level. Although glacial melt hadn’t caused Katrina, I was thinking about the indelible control the world’s ice holds over our coastlines. When the glaciers grow, oceans fall. When they shrink, oceans rise. Oceans and ice have danced in this way, embraced in lockstep, for hundreds of millions of years. From my geophysical training I knew this. From my own research and that of colleagues, I knew how quickly the world’s glaciers were retreating. And for miles inland behind me, and hundreds of miles along the coast in either direction, the ground on which I stood lay barely above the surf. I had understood all this before in abstraction, but this endless plain of destruction made it real.
Global sea levels are now steadily rising nearly one-third of a centimeter every year, driven by melting glacier ice and the thermal expansion of ocean water as it warms.258 There is absolutely no doubt about this. There is absolutely no doubt that it will continue rising for at least several centuries, and probably longer. Sea-level rise really is happening. The big unknowns are how fast, whether it will progress smoothly or in jerks, and how high the water will ultimately go.
We shall explore the scary possibilities of fast sea-level rise in Chapter 9; for now, let’s stick to conservative models and what has been measured thus far. In the 1940s, global average sea level was about ten centimeters lower than today, but was rising more than 1 millimeter per year (a brisk rate at the time). It is currently rising 2-3 millimeters per year, and that number is projected to grow by around 0.35 millimeters for each additional degree Celsius of climate warming.259
Depending on whose model you like, this means we are looking at around 0.2-0.4 meters of sea level rise by 2050, or calf-deep. The state of California has just begun damage assessment and planning for 0.5 meters by that time,259,260 around knee-deep. And 2050 is just the beginning. By century’s end, global sea level could potentially rise from 0.8 to 2.0 meters.261 That’s a lot of water—up to the head of an average adult. Much of Miami would be either behind tall dikes or abandoned. Coastlines from the Gulf Coast to Massachusetts would migrate inland. Roughly a quarter of the entire country of Bangladesh would be underwater.
When oceans rise, all coastal settlements face challenges. Higher sea levels expand the inland reach and statistical probability of storm surges like the one Hurricane Katrina blew into the Gulf Coast. Decidedly unhelpful is a two-in-three chance that climate warming will make typhoons and hurricanes more intense than today, with higher wind speeds and heavier downpours.262 And just as we saw for water supply, there are other, nonclimatic actors that make the problem even worse. In fact, all four of our global forces are conspiring to place some of the world’s most important cities at risk.
Most of the world’s largest and fastest-growing urban agglomerations—like Mumbai, Shanghai, and Los Angeles—are globalized port cities on the coasts. Their populations and economies are rising fast. Demographers and economic models tell us they will grow even more over the next forty years.
Particularly in Asia, many of these great cities are located on “megadeltas,” enormous flat protrusions of mud and silt that grow where large rivers drop off their carried sediment upon entering and dissipating into the ocean. These piles of sediment are ferociously attacked by the ocean’s waves and storm surges, but the rivers keep dumping more. Like giant conveyer belts of cement, they keep trundling material to the river mouths—often from thousands of miles inland—to overwhelm the ocean’s defenses. Over centuries to millennia, the rivers grow the land out.
These deltas have always attracted humans. Farmers love their thick, rich soils that are also flat, well-watered, and have few rocks. Ships can ply both oceans and continental interiors. The river brings in freshwater for towns and cities, then carries their wastes off to the sea. A delta’s flat terrain is appealing to build on; the surrounding swamps and forests are teeming with fish and wildlife.
The problem, of course, is that the very existence of deltas is maintained by the constant sedimentation from flooding and back-and-forth migration of their rivers. They are full of low-lying swales that inundate readily. As human settlements grow, there is increasing pressure to expand into these dangerous areas. This happens not only with deltas but urbanizing river floodplains as well, like Cedar Rapids in Iowa. Flood damages therefore rise as development pushes into low-lying swamps considered too dangerous before. The reason Katrina spared New Orleans’ historic French Quarter is that it was the first place to be colonized: Even in 1718 people knew to perch their houses on that crescent-shaped sliver of natural levee, piled a few feet higher than the nearby swamps where the Upper Ninth Ward would drown nearly two centuries later.
As delta cities grow and their rivers become oversubscribed or polluted, they start pumping their groundwater resources. Groundwater removal—from what is essentially a pile of wet mud—causes the delta sediments to compact and settle, lowering the delta’s elevation closer to that of the sea. Even in the absence of groundwater pumping, some settling is normal. In a natural system, this settling is compensated by fresh blankets of silt laid down by floods. But the dikes and levees built to protect delta cities also prevent these fresh reinforcements from arriving. Farther upstream, dams thrown across the river snare the delta’s lifeblood of new sediment. Dam operators groan and search their budgets for dredging money. The conveyor belt is cut. Hundreds of miles downstream, the ocean starts taking back the land.
Important delta cities are found all over the world. They face the triple threat of rising oceans, sinking land, and sediment-starved coastlines. Without replenishment their coasts are washing away, bringing ocean wave energy and storm surges ever closer to the sinking cities. When combined with projected trends of rising sea level, population, and economic power, this puts some of the world’s most populous and prosperous places in harm’s way.
The risk assessment study on the next page was recently commissioned by the OECD.263 The study considered all 136 of the world’s major port cities holding one million people or more. As of 2005, about forty million people living in these cities were considered to be living in places at direct risk from flooding. The total economic exposure to flooding—in the form of buildings, utilities, transportation infrastructure, and other long-lived assets—was about USD $3 trillion, or 5% of global GDP.264 Under current trajectories of population growth, economic growth, groundwater extraction, and climate change, by the 2070s the total exposed population is forecast to grow more than threefold, to 150 million people. The economic exposure is forecast to rise more than tenfold, to USD $35 trillion, or 9% of global GDP. Of the top twenty major at-risk cities, exposed human populations could rise 1.2- to 13-fold, and exposed economic assets 4- to 65-fold, by the 2070s. Three-quarters of these major cities—nearly all of them in Asia—are found on deltas. Clearly, we are about to begin paying great attention to a new kind of defense spending. It’s called coastal defense.
Top Twenty World Port Cities Most Vulnerable to global Sea Level Rise, Hurricanes, and Land Subsidence
(Sources: R.J. Nicholls, OECD, 2008)
The trends I’ve described—rising water demand; oversubscribed and/or polluted water sources; reduced time-delays and free storage from snow and ice; sharper floods and droughts that are also harder to predict and insure against; the competitive marriage of water to energy; and booming port cities on increasingly risky coasts—all stem from our four global forces of demographics, natural resource demand, globalization, and climate change.
Whether for-profit multinational corporations offer the best solution for tackling water quality problems in impoverished countries remains an open question that is heatedly debated. However, global trade flows of “virtual water” embedded in food, energy, and other goods are already smoothing out some stark water inequities around the world. Compared with other irritants, international water disputes have seldom led to war. Continued economic integration could foment even better water management across borders—especially when nudged along by free hydrologic data measured from space and posted openly on the Internet. Finally, the not-so-far-fetched possibility that new international trade flows in water—not just virtual but actual, physical water—could emerge as a partial solution for some water-stressed places that will be explored further in Chapter 9.
Looking ahead to the next forty years, it’s not hard to see where the big pressure points lie. Joseph Alcamo directs a research institute at the University of Kassel dedicated to exploring different possible futures for humanity’s water supply. To do this they built WaterGAP,265 a sophisticated computer model incorporating not only climate change and population projections but also other factors like income, electricity production, water-use efficiency, and others. WaterGAP is thus a powerful tool for simulating a range of possible outcomes depending on the choices we make.
A typical, “middle-of-the road” WaterGAP scenario is shown here for 2050.266 Regardless of how the WaterGAP model parameters are twiddled, the big picture is clear: The areas where human populations will be most water-stressed are the same areas where they are water-stressed now, but worse. From this model and others, we see that by midcentury the Mediterranean, southwestern North America, north and south Africa, the Middle East, central Asia and India, northern China, Australia, Chile, and eastern Brazil will be facing even tougher water-supply challenges than they do today. One model even projects the eventual disappearance of the Jordan River and the Fertile Crescent267—the slow, convulsing death of agriculture in the very cradle of its birth.
Computer models like these aren’t built and run in a vacuum. They are built and tuned using whatever real-world data scientists can get their hands on. Take, for example, the western United States. In Kansas, falling water tables from groundwater mining is already drying up the streams that refill four federal reservoirs; another in Oklahoma is now bone-dry. These past observed trends, together with reasonable expectations of climate change, suggest that over half of the region’s surface water supply will be gone by 2050.268 Kevin Mulligan’s projection of the remaining life of the southern Ogallala Aquifer requires no climate models at all—it simply subtracts how much water we are currently pumping from what’s left in the ground, then counts down the remaining years until the water is gone.
In the United States, the gravest threat of all is to the Colorado River system, the aorta of water and hydropower for twenty-seven million users in seven states and Mexico. It supplies the cities of Los Angeles, Las Vegas, Tucson, and Phoenix. It irrigates over three million acres of highly productive farmland. Global climate models almost unanimously project that human-induced climate change will reduce Colorado River flows by 10%-30%269 and already, its water is heavily oversubscribed.
More water is legally promised to the Colorado’s various shareholders than actually flows in the river.270 Its left and right ventricles are Lake Mead and Lake Powell, two enormous reservoirs created by the Hoover and Glen Canyon dams, respectively. They haven’t been full since 1999. A bitter combination of high demand, high evaporation, and falling river flows has thrown the Colorado River system into a massive net deficit of nearly one million acre-feet per year, enough water for eight million people. By 2005, Lake Powell was two-thirds empty and almost to “dead pool” (the elevation of its lowest outlet, below which no water can be released by the dam and it ceases to function).271 This desiccation stranded marinas and boat docks on dry land and left a white bathtub ring some ten stories high on Lake Powell’s newly exposed canyon walls. “It was as though in four years . . . Lake Powell had simply vanished,” wrote James Lawrence Powell of his namesake in Dead Pool.
I’m glad humanity has a decent track record with things like settling water disputes with courts rather than missiles, and exporting food from the places that have water to the places that don’t: If any of these model forecasts are correct, we’re going to need it. Humans currently withdraw about 3.8 trillion cubic meters of water annually, and are projected to require more than six trillion in the next fifty years. To serve India’s expected 2050 population of 1.6 billion, even with improved water efficiency, will require a near-tripling of its water supply. Farmers, energy utilities, and municipalities are all in competition for water. Put it all together and the numbers don’t add up. Something will have to give.
The survival of California’s thirsty dry cities—like Los Angeles and San Diego—seems all but guaranteed. Their populations and economies are growing briskly. Despite annual sales of over USD $30 billion, California agriculture still contributes less than 3% to the state’s economy—and cities use far less water than irrigated farms. Even with climate changes and a projected 2050 population of about 20 million, there will still be ample water for Angelenos and San Diegans to drink and shower and cook. Ample water for California farmers, however, is far less assured.
Forced to choose, cities will trump agriculture. Farmers will either lose or sell their historic water rights. Croplands will return to desert. The first signs of an urban takeover have already begun: After years of lawsuits, farmers of California’s Imperial Valley were forced to sell two hundred thousand acre-feet of their yearly Colorado River water allocation to San Diego in 2003. That fallowed twenty thousand acres of farmland. By early 2009 the Metropolitan Water District—supplier of twenty-six cities throughout Southern California—was trying to buy seven hundred thousand acre-feet more.272
Cities versus farmers: the real Water Wars.