Is the food scarcity scare for real

IN RECENT MONTHS, rising oil prices have focused the world's attention on the depletion of vital reserves, but the drying up of underground water resources from overpumping is a far more serious issue. Excessive pumping for irrigation to satisfy food needs today almost guarantees a decline in food production tomorrow. There are substitutes for oil; the same cannot be said for water.

The growth in population since 1950 exceeds that during the preceding 4,000,000 years. Perhaps more striking, the world economy has expanded sixfold since 1950. As the economy grows, its demands are outstripping the Earth, exceeding many of the planet's natural capacities to provide food, water, and the basic needs of daily living. Evidence of these excessive demands can be seen in collapsing fisheries, shrinking forests, expanding deserts, escalating C[O.sub.2] levels, eroding soils, elevated temperatures, disappearing species, falling water tables, melting glaciers, deteriorating grasslands, rising seas, and rivers that are running dry. Nearly all these environmental trends affect world food security.

Two of the newer trends--falling water tables and rising temperatures--are making it far more difficult for the world's farmers to feed the 76,000,000 people added to our numbers each year. Humans drink nearly four quarts of water a day in one form or another, but the food we consume on a daily basis requires 2,000 quarts of water to produce. Agriculture is the most water-intensive sector of the economy: 70% of all water pumped from underground or diverted from rivers is used for irrigation; 20% is employed by industry; and 10% goes to residences.

Water tables currently are falling in countries that contain over half the world's people. The vast majority of the nearly 3,000,000,000 individuals to be added to world population by mid-century will come in nations where water tables already are falling and wells are going dry. Historically, it was the supply of land that constrained the growth in food production. Today, though, the shortage of water is the most formidable barrier.

Rising temperatures are the second big threat to future food security. During the last few years, crop ecologists focusing on the precise relationship between temperature and crop yields have found that each 1[degrees]C rise in temperature during the growing season reduces the yield of grain--wheat, rice, and corn--by 10%. Since 1970, the Earth's average temperature has risen nearly 0.7[degrees]C (1[degrees]F). The five warmest years during 124 seasons of record-keeping occurred in the last seven calendar turns.

In 2002, record-high temperatures and drought lowered grain harvests in India and the U.S. These reduced harvests helped pull world grain production some 90,000,000 tons below consumption, a shortfall of more than four percent.

In 2003, it was Europe that bore the brunt of rising temperatures. The record-breaking heat wave that claimed 35,000 lives in eight countries withered grain harvests in virtually every nation from France in the west through the Ukraine in the east. The resulting reduction in Europe's grain production of some 30,000,000 tons was equal to half the U.S. wheat harvest.

Although climate change is discussed widely, we are not quick to grasp its full meaning for food security. Everyone knows that the Earth's temperature is rising, but commodity analysts often condition their projections on weather returning to "normal," failing to realize that, with climate conditions now in flux, there is no "normal" to return to.

The Intergovernmental Panel on Climate Change, a group of some 2,000 scientists, projects that the Earth's average temperature will rise during this century by 2-10[degrees]F. Young farmers face the prospect of higher temperatures than any generation of growers since agriculture began.

Higher temperatures in mountainous regions alter the precipitation mix, increasing rainfall and reducing snow accumulation. The result is more flooding during the rainy season and less snowmelt to feed rivers during the dry season. In Asia, for instance, this shift is affecting the flow of the major rivers that originate in the vast Himalayan-Tibetan region, including the Indus, Ganges, Mekong, Yangtze. and Yellow.

The world has been sluggish in responding to these new threats. In four of the last five years, the world grain harvest has fallen short of consumption. As a result, world grain stocks are at their lowest level in 30 years. Another large world grain shortfall this year could drop stocks to the lowest level on record and send world food prices into uncharted territory.

Among the trio of grains that dominate world food production--wheat, rice, and corn--the supply of rice is likely to tighten first simply because it is the most water-dependent of the three. Finding enough water to expand rice production is not easy in a world with spreading water scarcity. If rice supplies shrink and prices rise, the higher costs are likely to affect wheat as well.