The Future (34 page)

In just one of many examples of this particular variety of denial, when an expert from the University of Oklahoma, Luo Yiqi, visited Inner Mongolia in northern China a few years ago to study desertification, he was astonished to see fields of rice (one of the most water-intensive crops) grown with water that authorities allowed to be pumped at grossly unsustainable rates from deep aquifers. “Apparently,” he noted dryly, “
farmers did not get enough scientific guidance.”

The regrettable decision to ignore the depreciation of natural resources, while accounting precisely for the depreciation of capital goods, may have been subtly influenced by the state of the world when this formula was created in the 1930s. We were still in the last stages of the colonial era, when limitations on supplies of natural resources seemed irrelevant; industrialized countries could simply obtain more in their colonial possessions, where the supply seemed, for all intents and purposes, limitless. Global population has tripled since the national accounts were adopted, and the dangerous illusion that Kuznets warned about is now at the heart of the world’s failure to recognize the twin dangers of unsustainable depletion of both topsoil and groundwater.

Since the beginning of the Agricultural Revolution, these two strategic resources have both been essential for the production of food. The irrigation of crops emerged roughly 7,000 years ago and the Green Revolution of the twentieth century increased agriculture’s dependence on irrigation—particularly in China, where 80 percent of the harvest depends on irrigation, and India, where 60 percent depends on irrigation. (The
U.S. depends far less on irrigation.)

Large dams for water storage gained popularity in the late nineteenth and early twentieth centuries. There are now 45,000 large dams in the world, including on
all twenty-one of the world’s longest rivers. FDR’s economic stimulus program in the 1930s resulted in large-scale dam construction by the Tennessee Valley Authority in my home region, and the Bonneville Power Administration in the Pacific Northwest—and
of course, the majestic Hoover Dam on the Colorado River, which was the tallest in the U.S.
when it was built seventy years ago.

Prior to the Industrial Revolution and the explosion of urban populations, more than 90 percent of
global freshwater was used for agriculture. In more recent decades, the competition for water between agriculture, manufacturing, and fast-growing thirsty cities has led to growing disputes over water allocation—disputes that agriculture often loses. Today, more than 70 percent of the world’s freshwater is used to grow food, even though
780 million people in the world still lack access to safe drinking water. As noted earlier, the world has made significant progress in reducing the number of people who lack access to improved water resources (though little progress has been made in preventing the contamination of freshwater sources—both surface and groundwater resources—from human and animal waste and other pollutants).

Some deep aquifers have long been sealed from surface water. A recently tapped aquifer in the Northeastern United States, Patapsco (under the state of Maryland)
has water found to be one million years old. Similarly, the Nubian Aquifer (underneath the Sahara), the Great Artesian Basin (underneath northeastern Australia), and the Alberta Basin (underneath western Canada)
all also have water more than one million years old. But although these “fossil” aquifers are nonreplenishable, most scientists believe they are limited in their supply of water; the vast majority of aquifers are replenished slowly as rainwater filters down to them.

Until recently, the amount of information about groundwater depletion rates was spotty at best, and according to one expert, the threat to the resource is a
classic case of “out of sight, out of mind.” Indeed, so much water is now being withdrawn from underground aquifers that it is believed by experts to account for 20 percent of the sea level rise in recent decades (although scientists forecast that the accelerating ice loss from Greenland and Antarctica
will dramatically increase sea level rise later in this century).

The highest rates of groundwater depletion are in northwest India and northeast Pakistan, the
Central Valley of California, and northeastern China. One Chinese groundwater specialist found that an aquifer in northern China with water 30,000 years old was being used
unsustainably to irrigate crops in dryland areas. China has embarked upon the largest water project in history—the South–North Water Transfer Project
that has been under construction for decades,
intended to remedy water shortages in northern China. Asia, which has 29 percent of the world’s freshwater resources, is now using more than 50 percent of the world’s water. According to the United Nations, “In 2000, about 57% of the world’s freshwater withdrawal, and 70% of its consumption, took place in Asia,
where the world’s major irrigated lands are located.”

Africa has only 9 percent of the world’s freshwater, but is using 13 percent, and is expected by U.N. experts to have the most intensive increases in
water withdrawal in the coming decades.
Europe is consuming only a slightly larger percentage than its own supply. The Americas are fortunate in having more water than they use, but large regions—particularly Mexico and the Southwestern U.S.—
are already experiencing severe shortages. In 2011, more than one million head of cattle were
herded north from Texas to wetter, cooler pastures. Few expect them ever to return.

According to a study by the Scripps Institute, there is a “50-50 chance” that Lake Mead—the largest man-made lake in the western hemisphere, the one formed by Hoover Dam—
will run completely dry before the end of this decade. In addition, according to the U.S. Department of Agriculture, the water table beneath three of the largest grain-producing states—Kansas, Texas, and Oklahoma—
has dropped more than 100 feet, forcing many farmers to abandon irrigation. Reservoirs in the state of Georgia have also been running at dangerously low levels for several years.

Improving the efficiency of water use is a cost-effective option for ameliorating shortages in some areas. Many aging water distribution systems leak extraordinary amounts of water. In the U.S., for example, an important urban water line bursts every
two minutes on average, twenty-four hours a day. Some portions of older urban water systems were built over 160 years ago, and since then, have been—like groundwater resources—
“out of sight, out of mind.” Repairing municipal water pipes is expensive, but some cities are belatedly recognizing the necessity of undertaking this task.

According to ecologist Peter Gleick, we should view efficiency as a giant wellspring that could provide
vast new quantities of needed freshwater. Unfortunately, this wellspring, like many of the aquifers now being recklessly depleted, also seems to be out of sight, out of mind. The majority of
agricultural irrigation practices are still extremely wasteful.
Switching to scientifically precise drip irrigation techniques is cost-effective in most agricultural operations, but many
farmers have been slow to make the change. Another benefit of switching to more efficient and precise methods of irrigation is that wasteful and excessive irrigation of crops increases the salinity of soils—because the irrigation water usually contains small
amounts of salt that build up with continued use.

The recycling of water is growing in popularity. Some communities already require the use of greywater—used water that is not suitable for drinking but is
safe for watering plants. The more controversial recycling proposals take sewage water and remove all of the contaminants,
purify it, and put it into drinking water systems. There is still a great deal of consumer resistance to these plans, but some
communities have successfully implemented the approach.

In regions where rainfall is becoming more concentrated in large downpours—interrupted by longer periods of drought—many experts are calling for the increased use of cisterns to capture
more of the rainfall and store it for drinking water. This once common practice fell out of favor with the extension of underground water lines from reservoirs. I remember the cisterns we used to have on our family farm when I was a boy. We stopped using them when we got “city water.”

T
HE STATE OF
the world’s topsoil is threatened by the same willfully blind overexploitation that has caused shortages of freshwater. In the world’s prevailing system of accounting, neither water nor topsoil are assigned any value. Therefore, wasteful and destructive practices that diminish the supplies of both are invisible in the world’s economic calculations. Yet topsoil, along with water, is the basis for virtually all human life on Earth. More than 99.7 percent of food consumed by human beings comes from cropland, more specifically from the six to eight inches of topsoil that cover
roughly 10 percent of the Earth’s surface.

On a global basis, we are effectively strip-mining this crucial resource in an unsustainable pattern, by recklessly plowing erodible soils, overgrazing grasslands, taking arable land for buildings and roads to accommodate urban and suburban sprawl, tolerating reckless deforestation, and failing to use proven land management techniques that replenish soil carbon and nitrogen.

At present, every kilogram of corn produced in the American Midwest
results in the loss of more than a kilogram of topsoil. In some states, such as Iowa, the ratio is even higher: 1.5 kilograms of topsoil lost for each kilogram of grain. These rates of soil loss are not sustainable. They deplete soil carbon, thus damaging the productivity of the soil over time, and
accelerate the emission of carbon dioxide into the atmosphere.

We already know how to slow and reverse soil erosion, but global leadership would be required to mobilize the community of nations in the same way that FDR mobilized the United States in the 1930s. Organic agriculture with low-till and no-till practices can sharply reduce soil loss while simultaneously
increasing the fertility of the topsoil. Crop rotation, a technique that used to be widespread before industrial agriculture took over, can
replenish soil carbon and nitrogen.

Another once common technique that has since been abandoned in large areas of the world is the recycling of animal manure as fertilizer for crops. Factory farming—the clustering of thousands of head of livestock in crowded feedlots and feeding them corn—has turned this natural fertilizer into highly acidic toxic waste that is harmful to crops and thus becomes an
expensive liability instead of a valued asset.

A major study in 2012 by leading researchers at the University of Minnesota, Iowa State University, and the Agricultural Research Service of the U.S. Department of Agriculture showed that the use of
nontoxic manure as fertilizer and a three-year crop rotation designed to replenish soil fertility reduced the need for herbicides and nitrogen fertilizer by almost 90 percent, without reducing profits. One of the researchers, Professor Matt Liebman of Iowa State, said that one of the reasons farmers do not use the approach recommended in the study is that “there’s no cost assigned to environmental externalities.”

For the last century, modern agriculture has been based on heavy use of synthetic nitrogen fertilizer—90 percent of the cost of which is from natural gas, from which
virtually all of the nitrogen is derived. However, agricultural productivity growth has been slowing even as fertilizer
use per acre has been increasing dramatically. Moreover, the heavy use of nitrogen in agriculture has caused significant water pollution problems around the world as it runs off farmland with the rain and feeds uncontrolled massive algae blooms in coastal regions of the ocean—and dead zones, areas
devoid of life, which are growing in several ocean regions, including the part of the Gulf of Mexico into which the Mississippi River drains. In China the use of synthetic nitrogen fertilizer has increased
by 40 percent in the last two decades even though grain production has remained relatively stable; it is this nitrogen runoff that has produced the
recent spectacular algae blooms in Chinese rivers, lakes, and coastal areas.

Additional nitrogen emissions from the combustion of fossil fuels in factories, on farms, and in cars and trucks have created significant air pollution problems, particularly in the
U.S., China, Southeast Asia, and parts of Latin America. More efficient and targeted use of nitrogen fertilizers, and tighter restrictions on emissions from factories and vehicles, are needed to address the problem.

While nitrogen supplies are not limited, there is a potentially serious emerging limit to the supply of another crucial component of fertilizer—phosphorus, which is a relatively rare element on the Earth. Even as conventional sources of phosphorus are running out, modern agricultural techniques have
tripled the depletion of phosphorus from cropland.

The first warning about a phosphorus shortage in a 1938 message to Congress, by President Roosevelt, led to a successful worldwide search for additional reserves—including the discovery of phosphates near Tampa, Florida,
where 65 percent of U.S. production now takes place. But while the United States produces 40 percent of the world’s corn and soybeans, it produces only 19 percent of the world’s phosphorus, which, in the long run, is essential for agriculture to continue—and so now the
search for new reserves is beginning again.

Forty percent of the world’s current supply of phosphates (the most common form in which phosphorus occurs) is in Morocco, which has been called the
“Saudi Arabia of phosphorus.” The next largest reserves are found in China, which imposed a 135 percent tariff on
exports during the 2008 food price crisis. Many experts fear that similar hoarding of phosphorus could occur if food prices continue to go up, although other experts are more sanguine about the possibility of finding new sources in unconventional locations, such as the ocean floor.

Phosphorus is essential to all life, including human life. It makes up the backbone of DNA, among other things, and fully one percent of the bodyweight of human beings is made up of phosphorus; in fact, the seven billion people on Earth discard large quantities in urine every day.
Some countries are now actively exploring the recycling of urine in
order to extend the supplies of phosphorus for fertilizers.