SEATTLE – If today's global statistics of more than 3 billion malnourished people are worrisome, try projecting 50 years into the future, when Earth's population could exceed 12 billion and there could be even less water and land, per capita, to grow food.

The current level of malnutrition among nearly half the world's population of 6.3 billion is unprecedented in human history, says agricultural ecologist David Pimentel of Cornell University, Ithaca, N.Y. "Every trend – from decreasing per-capita availability of food and cropland to population growth – shows the predicament becoming even more dire," Pimentel says.

"In the next 50 years, the degree of malnutrition, resultant disease and human misery is unimaginable. But we have to try to consider the future while there is still time to make meaningful changes, to reverse these trends and ensure a sustainable food supply."

Pimentel's views were presented by his colleague, Paul Reitan of the University at Buffalo, today (Feb. 13) at the annual meeting of the American Association for the Advancement of Science (AAAS) in Seattle. The title of the talk was "The Importance of Soil in Sustaining Civilization."

In the prepared text, Pimentel said he saw several troubling trends:

• Harvests of cereal grains, the mainstay of human diets and 80 percent of the world food supply, have increased slightly since 1985 but not nearly fast enough to keep pace with increases in population.
• Rising malnutrition increases human susceptibility to other diseases, such as malaria, diarrhea and AIDS.
• The prediction of a 12 billion global population by 2054 is based on the current rate of growth with each couple producing an average of 2.9 children. Even if nations' policy changes reduce the birth rate to an average of 2 children per couple, the 12 billion mark would be reached in 70 years.
• Because more than 99.8 percent of human food comes from the land, doubling the planet's population will further stress resources for fresh water, renewable and fossil energy, fertilizers and pesticides.
• For the most finite resource of all, land, each year more than 10 million hectares of cropland are degraded and lost because of soil erosion. This comes at a time when food production should be increasing dramatically to meet the needs of a rapidly expanding population. Pimentel noted that per-capita cropland has declined 20 percent worldwide in the past decade.

"The only way to reverse the growing imbalance between human population numbers and food supply is to actively conserve cropland, fresh water, energy and other environmental resources," Pimentel said.

"We must focus on developing appropriate, ecologically safe agricultural technologies for increasing food production. Either we are brave enough to limit our numbers or nature will impose its limits on our numbers and existence," he added.