by Frank Rijsberman
“Water flows uphill to money.”
Marc Reisner ~ American author ~ Cadillac Desert, 1986
To produce a calorie of food, it takes a liter of water or at least several thousands of liters of water for every person every day. The water required to grow the food we eat is some 70 times greater than the water we need to drink, bathe and wash. Over the next 40 years, the global demand for food is expected to double, and that implies that the amount of water used to achieve global food security would also have to double.
Already today a third of the world population is affected by water scarcity. Climate change is expected to worsen this by increasing the frequency and severity of floods and droughts.
That, in a nutshell, paints the grim reality of water and food security. It has led to predictions that future wars will be fought over water and that water will become the blue oil of the 21st century.
What are the water and food challenges faced by the world? Why are they so poorly understood? How did we end up in such a dire situation? Are there solutions to alleviate the world water crisis? These are the questions this article will address.
Hydrocivilizations
In some parts of the world, such as Western Europe and the U.S. Midwest, it is possible to grow high-yielding crops with the moisture provided by rainfall alone. In many others, however, it is either too dry, such as in the Middle East, North Africa and much of California, or rain falls in just a few big storms every year, such as in monsoon Asia. Civilizations that flourished under these conditions all depended heavily on their ability to manage water for agriculture. Irrigation on the banks of the river Nile was the source of wealth in ancient Egypt. Roman aqueducts and underground water tunnels were widespread masterpieces of engineering, some of which have survived until today. Famous kings and maharajahs in southern India and Sri Lanka are remembered as much or more for their dam-building feats as their prowess on the battlefield. Food security has been closely intertwined with water management for millennia, but the speed at which water resources have been developed in recent history has been unprecedented.
During the 20th century, the world population tripled, but the total amount of water extracted from rivers and groundwater aquifers for human use has increased sixfold. By the middle of the last century the global stock of large dams, defined as dams higher than 15 meters, numbered 9,000, three-quarters of which were located in industrialized nations. Today there are some 49,000 large dams in the world, two-thirds in developing countries, particularly in Asia. At the same time, the development of affordable small diesel and electric water pumps led to a boom in groundwater development. In India alone more than 20 million boreholes were drilled and pumped, primarily for irrigation. At the end of the 20th century global food production was ample to feed the world population (if only the poor could afford it) and food prices were at historic lows, in no small way thanks to a massive global investment in water resources development for food security, hydropower and flood control.
The Green Revolution
In the 1960s and 1970s, rapidly increasing populations in the Southern Hemisphere and dramatic famines in the Indian subcontinent and sub-Saharan Africa led to widespread fears that the Earth would not be able to support a then-projected population of 6 billion. The Ford and Rockefeller foundations took the lead in initiating major international efforts to boost global food production. These collectively have become known as the “Green Revolution.” The best-known element of this revolution was the much-improved varieties of food crops such as rice, wheat and maize. This effort also yielded the only Nobel Peace Prize ever awarded an agricultural scientist, Norman Borlaug, in 1970 for his development of “famine-busting” semi-dwarf, high-yield, disease-resistant wheat varieties.
This boost in agricultural production required fertilizers and irrigation. The assumption was that making water available cheaply to farmers was part of the core infrastructure, along with roads for example, necessary to boost development and achieve food security. Supported by the World Bank and many bilateral donors such as the U.S. Agency for International Development, governments throughout Asia and to some extent Africa followed in the footsteps of the massive dam- and irrigation canal-building programs in places like the western U.S. and Australia’s Murray-Darling basin. Farmers invested simultaneously in wells and pumps for groundwater development. By the start of the 21st century, 17 percent of agricultural land was irrigated and it produced some 40 percent of the world’s food. Countries such as Thailand, India, Vietnam and Mexico became food exporters, despite their population increases.
The Value of Water
Water resource development efforts historically focused on diverting water in rivers and aquifers for use by agriculture, cities or industry. Large wetlands such as the Florida Everglades were seen as wasteland and a source of diseases such as malaria. Assuming that water had zero value in nature, any value produced through irrigation was seen as a contribution to society. The dominant policy around the world was for governments to bear the cost of investment in water infrastructure and to provide the resulting irrigation water to farmers free of charge — or at prices below the cost of operation and maintenance.
This policy had unanticipated consequences. Farmers receiving free or near-free water had no incentive to use it wisely or to invest in water conservation technology. Another consequence was that the massive government bureaucracies created to provide the water to farmers depended for their existence on government budgets rather than revenues from farmers. The bureaucrats had no incentive to be accountable to farmers or to provide high-quality service. In many places irrigation officials devised ingenious ways to informally extract personal revenue — from bribes on construction or maintenance contracts to providing privileged, secure access to farmers willing and able to pay extra. Better-off landowners and irrigation officials all had reason to hide, protect and perpetuate these informal arrangements. Poor farmers got less than their fair share, however, and society as a whole paid the price of a low-performing system. The water used generated a much lower value than it could.
Over time, societies gradually have recognized that “undeveloped” water does have great value. A river and the wetlands, deltas and coastal mangroves that depend on it support a number of vital functions:
• Fisheries.
• Flood plain uses such as recession agriculture, herding and flood plain forestry.
• Flood protection.
• Carrying nutrients to flood plains.
• Maintaining deltas and coastlines that erode without sediment.
In short, wetlands and coastal zones are now valued for the ecosystem services they produce.
The lesson is that all water already serves a purpose — and it all has a value. Some irrigation projects have generated less value for society than the ecosystems they replaced.
Running Out
The old approach to water resources development has reached its limits. Projected population increases require additional food production even as growing wealth in countries such as China and India increases per capita food consumption. The trends together suggest a doubling of world food demand between now and 2050. Business-as-usual would then require doubling the amount of water used in agriculture as well. That could in theory be done by increasing the land under cultivation, but there is simply not enough left. Another strategy might be to draw more water from nature, but the easiest rivers to tap and the best sites for dams have already been taken. In fact, there are many signs that too much has already been taken:
• Once-mighty rivers such as the Yellow, Colorado and Jordan no longer reach the sea during critical periods.
• The Aral Sea has dried to a shadow of its former self and has become one of the worst environmental disasters in the world.
• Groundwater levels in many parts of Asia, such as the Indian state of Gujarat, have fallen by more than 150 meters in 25 to 30 years; thousands of wells and whole villages have been abandoned — the aquifer was developed and used up in just one generation.
• A prolonged multiyear drought in Australia recently ravaged irrigated agriculture and has led to a 10-year peak in global wheat prices.
• California courts have limited the diversion of water for irrigation from Northern California and cities in the southern part of the state to protect endangered species in the San Joaquin–Sacramento river delta, causing a crisis for irrigated agriculture in one of the world’s most productive agricultural systems.
• Egypt’s Nile, breadbasket since the time of the pharaohs, no longer has enough water to provide more than half the food needed for the country; the remainder has to be imported.
The only realistic option is to increase the productivity of water already in use, producing more crop per drop and more value per drop — for food, for jobs, for health and for the environment. That is a major challenge, particularly where subsidized water prices do not provide incentives to increase productivity, but it can be done.
Climate Change
Just as food security depends on access to food rather than total food production alone, vulnerability to climate change depends on the capacity to adapt rather than climate risk alone. With respect to water, the key both to attaining food security and to managing climate risk is the ability to manage the daily and interannual variation in rainfall (for rain-fed agriculture) and river runoff (for irrigated agriculture).
The day-to-day variability of rainfall is the major risk factor for most forms of agriculture. Changes in rainfall patterns (in both space and time) will therefore be the most important aspect of climate change in terms of food security. Many adaptation options are variations of existing climate risk management, particularly irrigation systems. Irrigation systems offer an ability to manage water and thus to increase resilience in the face of climate change. On the other hand, river basins that are already “running out” have high climate vulnerability.
Poor People Pay the Price
The world produces enough food to feed everybody, an estimated 17 percent more than the recommended 2,700 calories per person per day. And yet the United Nations Food and Agriculture Organization (FAO) estimates indicate that a huge portion of the world’s population goes hungry. The most recent figure puts the number of malnourished at 925 million, 13 percent of Earth’s total population, and up from 824 million in 1990. Poverty is the main cause of hunger. Hungry people either do not have enough land to grow their own food, or enough cash income to buy it. That implies that simply producing more food is unlikely to cut the number of hungry people, unless it is done in a way that provides jobs and incomes for the hungry.
Managing Our Way Out of the Crisis
Can we increase the productivity of water enough to support a doubling of food production by 2050? Can we do so in a manner that cuts the number of malnourished and maintains or improves ecosystem services? The good news is that water productivity is currently low in most places. That means there is scope for improvement. The value of water in irrigation can range from 1 to 2 U.S. cents per cubic meter when used to produce grains, to 5 to 10 cents for cash crops such as sugar cane, and up to 50 cents for fruits and vegetables. But this figure depends not only on the crop, but also on location, agricultural practices and water conservation techniques. While most farmers need 1 to 2 cubic meters of water to produce a kilogram of grain, others manage with less than half a cubic meter. There is thus significant potential for farmers to produce more crop per drop. It will not be achieved easily, however. It is a problem many have tried to solve, and few have succeeded.
Silver bullets, such as the high-yielding varieties that boosted crop yields by as much as 50 percent in just five years in India and Pakistan in the 1970s, are not available. Some solutions are not expensive, but they require large-scale institutional change both in water management and in accountability to users. Both are tough to achieve. Some solutions may be found in technological breakthroughs, such as the drip irrigation systems developed in Israel that can double water productivity, but adopting new technology often requires capital investments beyond the means of most small farmers.
Managing water to achieve food security for all and a healthy environment will require massive efforts. Governments everywhere will have to phase out subsidies, recognize environmental values and stop the race to the bottom where those with means out-compete their neighbors with ever deeper wells. Adapting to climate change will become a priority everywhere. Industrialized nations will emphasize:
• Curbing the spread of complex chemicals such as pesticides, drugs and medications.
• Reviving ailing ecosystems, e.g., by decommissioning dams.
• Enabling water to move to its highest-value use.
In developing nations, food security for all requires a focus on opportunities for the poor. Particularly helpful will be initiatives that help the needy grow food and generate income. These might involve low-cost drip irrigation, rainwater harvesting or multiple-use water projects that afford households water to drink and bathe, water backyard gardens, tend livestock or support cottage industries.
In short, while food security in the 20th century was achieved by rapidly increasing the amount of water extracted from nature, the challenge for water managers now is to double the productivity of the water already used in the next 40 years.
Frank Rijsberman, former manager of environmental and health programs for Google.org, a philanthropic organization funded by Google Inc., now leads the water, sanitation and hygiene program at the Bill & Melinda Gates Foundation. He is former director of the International Water Management Institute in Sri Lanka.