The present situation, however, is different, says Lester Brown, president of the Earth Policy Institute in Washington. It's based on trends, not specific incidents. Longer-term trends include the growing world population and the desire of huge numbers of increasingly prosperous people in China, India, and elsewhere to eat more meat and eggs. A shorter-term problem, he says, is the growing use of corn and other foods to distill biofuels for cars, trucks, and other energy uses.
Unless the food-shortage situation is tackled seriously and quickly, the world faces increased social unrest, food riots, political instability, and more failed states, notes Mr. Brown. "Civilization is now at risk," he says.
Other observers are not quite that worried. "You could construct that scenario," says Mark Rosegrant, an expert at the International Food Policy Research Institution in Washington. "The probability of famine has gone up." And his economic models of world food demand and supply suggest high food prices are likely to continue "for a number of years."
Nonetheless, Mr. Rosegrant hopes that concerted, major investments to boost world food output will keep shortages down to the malnutrition level in some of the world's poorer nations. The solution includes improving farm infrastructure and technological boosts to farm yields – "a lot of small green revolutions, particularly in Africa," he says.
Not much can be done in the short term about the rise in the world's population. When President Bush first assumed office, there were 6 billion people in the world. When the next president's term ends in 2012, there likely will be 7 billion people, most of the additions in South Asia and Africa. India will add 500 million, reaching 1.6 billion. Africa's population, now 950 million, will grow by 1 billion.