Feeding a future world

Posted: 15 September 2000

Author: Don Hinrichsen

Author Info: Don Hinrichsen is a Contributing Editor to People & the Planet.

Although some experts are confident that a future world of eight or ten billion people will be able to feed itself, others share grave concerns about the future sustainability of current farming practices - especially in poor, food deficit countries with growing populations. Don Hinrichsen reviews the latest evidence.

There are three worlds when it comes to agricultural production: the haves, the poor have-nots and the rich have-nots. The haves - the United States, Canada, most of Europe and Australia - have sufficient cropland to meet most of their food needs and efficient agricultural production systems enabling them to produce more food from the same amount of land.

These countries share some common characteristics: they have reached a demographic transition to lower fertility rates, they are net food exporters, they are probably capable of expanding food production beyond current levels, and they are moving, however slowly, towards more sustainable agricultural production systems.

The poor have-nots consist of the bulk of the developing world - nearly all of sub-Saharan Africa, seven countries in Latin America, seven in the Middle East, six in Oceania, with most of the rest in South and Central Asia.

Villagers preparing the ground for planting, Haiti© Mark Edwards/Still PicturesThese countries contain more than half of humanity, over three billion people, and for many reasons cannot produce nor import enough food for their populations. In many cases their food production capacities are deteriorating in the face of rapid population growth, misdirected agricultural policies and widespread land degradation.

The third group is a mixed bag. It includes land-short Japan and Singapore, two of the world's richest economies, along with rapidly developing countries such as China and Indonesia in Asia, and Saudi Arabia and the other Gulf States in the Middle East. These countries, diverse as they are, share one common denominator: they cannot grow enough food to feed their populations, but have the financial resources to make up the shortfall through imports. All are struggling to improve agricultural systems and make them more efficient.

Japan is an anomaly. It can probably expand rice production, but current prices make it far cheaper for Japan to import additional rice rather than grow it on increasingly expensive land at home.

Despite the fact that the world grain harvest tripled between 1950 and 1990, keeping well ahead of population growth, it has tapered off dramatically in the last decade. However, during the same period that grain yields continued to increase, the amount of grain area per person was declining. This is a reflection both of population growth and the loss of cropland due to urban expansion, soil degradation and a number of other factors. In 1950, the world averaged 0.23 hectares per person. By the mid-1990s that had been whittled away to just 0.13 hectares.

The world's population is now over 6 billon, growing by 78 million a year. Most of this growth is concentrated in those developing countries least able to cope with the resource and food consequences of such growth. Lester Brown, President of the Worldwatch Institute in Washington DC, is worried. "Both the area of cropland and the amount of irrigation water per person are shrinking," he points out. " And threatening to drop below the level needed to provide minimal levels of food security."

Some other experts are more sanguine about the long-term prospects, but some promising exceptions, most of the world is not headed in the direction of sustainable agriculture. And the following problems are making the quest for sustainable food production systems even more difficult.

Limited land

Although the amount of potentially arable land is 40 per cent more than is currently cultivated, according to the UN Food and Agriculture Organisation (FAO) - an extra two billion hectares - most of the uncultivated land is marginal, with poor soils and either too little rainfall or too much of it. Bringing it into production would require costly irrigation systems, or large-scale soil fertility enhancement measures. Without massive technological change or substantial investments, increases in food production will have to come from existing agricultural land.

Smaller farms

One effect of rapid population growth is the shrinking size of family farmsteads. In most developing countries the size of small family farms has been halved over the past four decades, as plots are divided into smaller and smaller pieces for each new generation of male heirs. In 57 developing countries surveyed by the FAO in the early 1990s, over half of all farms were found to be less than one hectare in size, not enough to feed a family with four to six children. In India, nearly three-fifths of all farms are less than one hectare.

At the same time, control over farmland is increasingly concentrated in the hands of large-scale farmers. In Guatemala, for example, only 3 per cent of farmers control 65 per cent of the most productive agricultural land. In some countries production of export crops has taken priority over food crops, a policy that favours large-scale, commercial agriculture. It also makes rural people more vulnerable to shifts in markets and fluctuating prices.

Sustainable farming, Nepal© Don HinrichsenDegrading land

Nearly two billion hectares of crop and grazing land is suffering from moderate to severe soil degradation, an area larger than the United States and Mexico combined. Soil erosion from wind and water is the main agent of soil degradation. Every year, some 25 billion metric tons of topsoil is stripped away from the world's farmland; five billion is lost in China alone.

Much of this soil is washed into rivers and streams, where it clogs waterways and snuffs out aquatic life. China's Huang (Yellow) River empties 1.6 billion metric tons of soil a year into the Yellow Sea. The United States has lost a third of its topsoil since colonial times. Researchers in the Philippines estimate that 1.2 million hectares of cropland - one-third of the total hectarage - have been severely degraded from the over-use of pesticides and chemical fertilisers.

On an annual basis, soil erosion and other forms of land degradation now rob the world of 5-7 million hectares of farming land. Globally, land degradation threatens the livelihoods of at least one billion people, the majority of them in poor developing countries.

Desertification, the process by which productive drylands become wasteland, now affects about 2.6 billion hectares of range land, just over 60 per cent of the total. Agricultural, forestry and livestock losses on drylands amount to over $40 billion a year, according to one estimate by the UN Environment Programme. The Institute of Soil Management in Kazakstan has estimated that the country will lose 30 per cent of its grain land to soil erosion and desertification. Globally, the livelihoods of 800 million to one billion people are at risk from the insidious processes of desertification.

Irrigation troubles

Although only 17 per cent of all cropland is under irrigation, these lands produce a full one-third of the world's total food supply. However, due to badly planned and poorly built irrigation systems, the yields on one half of all irrigated land - amounting to around 120 million hectares - have fallen in recent years.

There are two main reasons for this: salinization and waterlogging of crops. In many dry, arid areas, salts that naturally occur in the soil must be drained away with irrigation runoff. If not, they accumulate in the soil, eventually working their way to the surface killing crops and poisoning the land. By the same token, improperly drained irrigation water can also raise the groundwater table until it reaches the root zone, drowning the crops.

The FAO estimates that salt build-up in soil has severely damaged 30 million hectares of the world's 240 million hectares of irrigated land. Another 80 million hectares are affected by a combination of salinization and waterlogging. Salinity has cut yields on nearly one-quarter of China's irrigated land and 21 per cent of Pakistan's. These trends are alarming considering that more than 60 per cent of the value of Asian food crops comes from irrigated agriculture.

Improving irrigation efficiencies would help reduce the twin scourges of salinization and waterlogging. Currently, on average, no more than 50 per cent of water withdrawn for irrigation purposes actually reaches the crops. It soaks into unlined irrigation canals, leaks out of pipes and evaporates on its way to the fields.

The resulting loss of irrigated cropland has led David Seckler, Director General of the International Irrigation Management Institute to conclude that such losses may be exceeding the gains, leading to a shrinkage of the world irrigated area.

Water shortages

The world's emerging crisis in irrigation is ultimately a water crisis. Water, after all, is a finite resource. There is only so much circulating in the world's hydrological cycle. Already, most of Africa and the Middle East, much of western United States and northwest Mexico, parts of Chile and Argentina, and nearly all of Australia suffer water shortages.

Scientists, like hydrologist Malin Falkenmark of Sweden, have calculated that in 1990, 28 countries containing 335 million people faced chronic water stress or outright scarcity. By 2025, water shortages may plague up to 52 countries, affecting as many as 3.2 billion people; roughly 40 per cent of the projected global population.

Africa and the Middle East are already experiencing acute shortages. Over the decade of the 1990s Kenya's per capita water supply will be cut in half and Egypt will have only two-thirds as much for its citizens. By the year 2000, six of East Africa's seven countries and all five nations on the south rim of the Mediterranean will face critical water shortages.

Collectively, the 20 countries comprising the Middle East and North Africa face the worst shortages. Today, annual per capita water availability is only 1,250 cubic meters, 60 per cent less than in 1960. By 2025, per capita supplies are expected to fall to 650 cubic meters, a further 50 per cent drop. Jordan and Yemen already withdraw 30 per cent more water from their groundwater aquifers every year than is being replenished.

Water woes are affecting a number of countries in Asia as well. Excessive pumping of groundwater for agriculture in Tamil Nadu, one of India's southern states, caused the water table to drop close to 30 meters in a decade. In the north Indian state of Uttar Pradesh the number of water-short villages soared from 17,000 to 70,000 in two decades; of 2,700 water wells supplied by the government, 2,300 have dried up. Across northern China, 300 cities now experience water shortages during all or part of the year; Beijing's water table is sinking at the rate of about two meters a year and a third of the city's wells have dried up.

The other problem with water supplies is that they are becoming increasingly polluted. Surface waters in many countries, developed and developing alike, are horribly polluted with untreated or partially treated municipal and industrial wastes and agricultural runoff (from fertilisers, pesticides and animal wastes). The world is generating 2,300 cubic kilometres of wastewater a year. Since it takes at least 10 times that amount to dilute pollutants the old phrase, "the solution to pollution is dilution", takes on rather grotesque connotations.

Nearly all of India's rivers have been turned into open sewers. Out of 78 major rivers in China, 54 are seriously polluted. More than 40 of Malaysia's rivers are so fouled with municipal, industrial and agricultural wastes that they are biologically dead.

Since 70 per cent of all water withdrawn every year is used for irrigated agriculture, current and expected water shortages, combined with loss of water quality from pollution, are emerging as major constraints on development in general and food production in particular.

Collapsing fisheries

While land-based food systems are under pressure, the harvest from the sea has already peaked.

During the last three decades the reckless expansion of the world's fishing fleet, coupled to quantum leaps in fishing technologies and a dim understanding of fish population dynamics and ecosystem interactions has led to the over-exploitation of nearly every commercial fishery in the world's seas.

By 1998, according to FAO, nearly 69 per cent of the world's marine fish stocks were either "fully-to-heavily exploited, over-exploited, depleted or slowly recovering." Only a concerted international effort, perhaps led by the UN, can offer hope for better management of fish stocks.

Genetic diversity

Meanwhile, plant breeders are alarmed about the continuing genetic erosion of the earth's wild strains of cereals and other cultivars.

After 10,000 years of settled agriculture and the discovery of some 50,000 varieties of edible plants, 15 provide 90 per cent of the world's food energy intake. Just three of them - rice, wheat and maize - are the staple foods for four billion people, two-thirds of humanity.

Dependence on a few crops is downright dangerous: disease can spread rapidly through monocultures, as it did through the Irish potato harvest in the 1840s, killing a fifth of the country's population. FAO estimates that since 1900, about three-quarters of the genetic diversity of domestic agricultural crops has been lost. And the destruction continues.

According to the International Centre for Agricultural Research in Dry Areas (ICARDA) up to 60,000 plant species - roughly 25 per cent of the world's total - could be lost by the year 2025 if the current rate of plant genetic erosion is not halted. Tropical deforestation, rapid urbanisation, the destruction of vital wetlands and the cultivation of drylands has destroyed countless habitats for wild progenitors of domestic crops.

Dryland plant species are particularly hard hit. The world's genetic centre for wheat - the Middle East - has seen massive losses of natural habitat, areas that once sheltered valuable genetic reserves of wild wheat are now gone forever.

Without constant infusions of new genes from the wild, geneticists cannot continue to improve domestic crops. Cultivars need to be reinvigorated every 5-15 years in order to give them greater protection against diseases and insects. The most effective way to do this is to interbreed domestic varieties with wild ones.

One example shows just how vital this is. In 1970 virulent plague devastated one-sixth of the US maize crop, wiping out half the harvest in some southern states, at a cost of $2 billion. Plant breeders seeking a solution found two ancestors of modern maize in Mexico. Once developed, these two varieties of wild maize conveyed resistance to seven of the domestic crop's major diseases. Called the botanical find of the century, they might have been missed entirely. Only a few stalks of these ancient progenitors were found in an abandoned lot slated for development.

Continued genetic erosion of the wild relatives of domestic cultivars continues. The prognosis is not good, unless ways can be found to conserve areas of high biological diversity in their natural environment. Seed banks contain a growing ex situ collection of wild plant varieties. However, once collected and frozen in a gene bank they may be saved, but they cannot evolve further. Both types of seed banks need to be expanded.

Food security

According to experts like Lester Brown of the Worldwatch Institute and Paul and Anne Ehrlich of Stanford University, there are three fundamental issues that need to be addressed before sustainable agricultural systems can be successfully introduced into many food deficit countries.

First, as a result of inequitable land use, mounting population pressures and migration, the capacity of farming communities in developing countries to produce food, manage land and protect the environment is being undermined. There is an urgent need - especially for the 82 food deficit countries identified by FAO - to slow population growth while at the same time promoting sustainable agriculture.

Tomato fields, Egypt© Ron Giling/Panos PicturesSecond, despite adequate food supplies on a global level, food is neither produced nor consumed equitably. Market forces have not been able to meet global food needs, despite large surpluses in some countries and large deficits in others. In food deficit countries, the needs and potential of poor subsistence farmers, many of whom are women, are often overlooked or ignored. Within families, women and girl children often do not have equal access with men and boys to nourishing food. Without increasing access to food supplies for the most vulnerable, there is little prospect for long-term global food security.

Third, the main cause of malnutrition is poverty. Absolute poverty means poor diets and malnourishment. Although the percentage of hungry people has dropped over the past 20 years, their numbers have increased because of population growth. Today, an estimated two billion people suffer from micro-nutrient deficiencies in their diets and 840 million of them are chronically malnourished.

In order to accommodate the eight billion people expected by 2025, the world will have to double food production over current levels. This not only requires a different sort of green revolution, it also requires a "blue revolution" in terms of water conservation and sustainable use.

There have been some promising technical developments. The International Rice Research Institute in the Philippines announced that it has developed a super rice capable of boosting yields by 25 per cent, amounting to an extra 100 million metric tons a year. But if there is not enough water to irrigate this new strain, yields will not increase substantially, if at all.

The bottom line is food security cannot be achieved if two natural resources essential to agricultural production - land and water - continue to become increasingly degraded and polluted. Steps must be taken soon to reverse this course before irreversible damage is done to the world's finite resource base. How small farmers, and communities, can best be involved in this process is the subject the reports which follow.