"The first essential component of social justice is adequate food," said Nobel laureate Norman Borlaug. He received the 1970 Peace Prize for improving agricultural productivity. His "Green Revolution" saved literally hundreds of millions from famine.

The world's population is expected to grow from today's 6 billion to about 8 billion by 2030. It's expected to peak at 10 billion and then decline. Feeding these people without sacrificing native ecosystems will require advances in agricultural productivity. Agricultural biotechnology, specifically the careful use of genetically engineered (GE) crops, holds great promise. GE crops can dramatically increase crop yields and spare millions of acres of wildlands from being cleared.

For centuries plant breeders have developed crops with desirable traits, e.g., by hybridization. Now, using advanced techniques of molecular biology, scientists can identify one or a few pieces of DNA from similar species or even from unrelated organisms and transfer those desirable genes into crops.

For example, genes from the bacterium Bacillus thuringiensis produce a toxin that kills certain insects. It's harmless to other creatures, including humans. This "natural" insecticide was extolled by Rachel Carson in her 1962 book, Silent Spring. Now, a copy of the Bt gene can be inserted into plants, enabling them to produce Bt toxin. This has significantly reduced the amount of insecticide applied to cotton in the United States. In conventional agriculture, cotton requires huge and multiple applications of synthetic chemicals.

GE techniques are already reducing chemical pesticide application by over 20 million pounds annually, lowering soil erosion by up to 90 percent by enabling conservation tillage, and increasing carbon sequestration by 4 metric tons per acre.

Hundreds of millions of people have been eating GE crops for years with no adverse health effects. (Over 70 percent of U.S. processed foods, e.g., canola, corn, and soybeans, contain GE ingredients.) European Union Commissioner for Health and Consumer Affairs David Byrne finds no scientific evidence of added risk to human health or the environment from any of the GE products currently on the market. He points to 81 separate scientific studies, all EU-funded, that bolster this conclusion.

But, touting the "precautionary principle," some argue that new technologies should not be introduced until tested for unknown risks. This is an intellectually bankrupt position for it requires proving a negative, a practical impossibility. Under this theory, all inventions and scientific advances would have to prove they wouldn't ever cause harm to the environment or human health. Clearly, there is no way to test for all possible effects of new products and procedures given the billions of possible interactions.

The vast majority of the crops that we eat today are the result of substantial human manipulation. Consider corn. Centuries of breeding have selected for a plant that will reproduce only with human intervention. Unharvested and left to mature, a corn plant will simply fall over and rot. Corn requires the husks of the seed pod to be stripped in order to release its seed.

Are we hardwired by evolution to be skeptical of "new" foods? An entire industry has developed under the general proposition that "natural" products are benign. But this is not the case. Dr. Bruce Ames, Director of the Environmental Health Sciences Center at U.C. Berkeley, notes that food in the human diet has evolved to contain thousands of natural toxins. They protect plants from insects and disease. It turns out Americans eat about 1,500 mg of natural pesticides per person per day. (This is 25 times the recommended daily consumption of vitamin C.)

Natural and synthetic compound are indistinguishable in their ability to cause cancer. Many fruits, vegetables, herbs, and spices have naturally occurring pesticides that are rodent carcinogens. The list includes apples, apricots, and bananas. Only 28 of the 1,000 chemicals in coffee have been tested and 19 of the 28 are rodent carcinogens. If opponents of GE foods were consistent in their opposition to risk, none of these "natural" foods would be on the market.

With bioengineered plants, farmers now have the potential to embrace the next agricultural revolution. This holds the promise of improving both human health and the natural environment.