Among the tree-lined bike paths, automated livestock pens and darkened lecture halls of the University of California at Davis, a tiny room holds a weapon of mass destruction. Here, behind locked doors, sits a chunk of Xanthomonas, a bacterial blight that has decimated rice harvests in China, India, Indonesia, Malaysia, the Philippines, Thailand, Vietnam and West Africa. Since the passage of the Bioterrorism Preparedness and Response Act of 2002, the U.S. Department of Agriculture has deemed Xanthomonas a "select agent," which meant that in order to enter I had to produce a photo I.D., sign a series of documents, and suit up in a disposable lab coat. Within the restricted area, a staff researcher snapped on a pair of rubber gloves, unlocked an incubator, and extracted a petri dish of yellowish goo, which he held a few inches from my outstretched hands. "I can't let you touch it," he said.
It may have looked like nothing more than a lump of mold, but the pathogen that could rot the grain that feeds half the world had also introduced a new and ominous twist to the story of mankind's greatest agricultural triumph: the green revolution. Since the days of Thomas Malthus, many scientists have feared that the Earth could not produce enough food to sustain its rapidly growing population. While some contended that science would find a way to overcome such limits, the Malthusians pessimistically maintained that the world possessed a finite amount of arable land and that each acre of that land could produce only a given amount of harvest in a given growing season.
Keeping pace with an exploding population meant either creating more land to farm or making the existing farmland more productive. And it was the green revolution that introduced the agricultural breakthroughs that provided the means to do both. Innovations in dam construction and irrigation increased the amount of arable land. At the same time, scientists discovered how to use fossil fuels to create powerful synthetic fertilizers to make that land more productive. Chemists found new ways to battle pests and viruses, and geneticists discovered how to make the plants themselves hardier and more nutritious. More land produced more food, and the result of all this abundance was major, seemingly sustainable population growth. In 1911, when German chemist Fritz Haber first demonstrated how to create synthetic fertilizer, the Earth's population was about 1.7 billion. Since then, it has doubled, and then doubled again.
Now billions of people rely on the continued success of those four innovations: irrigation, fossil-fuel-based fertilizer, chemical pesticides and genetics. But the exorbitant expenditures of resources that guaranteed the success of the first green revolution may no longer be possible. After all, the Malthusians were not wrong about the limits of growth. Today we are rapidly depleting and polluting our sources of freshwater, and much like the planet's population, the price of oil has also doubled and doubled again. Nor can anyone ignore the virulent agri-clouds of insecticide and herbicide, much less the agricultural runoffs that have produced dead zones in our oceans. Of all the green revolution's innovations, only the science of genetics has proved sustainable.
That was why I had come to the Ronald Laboratory, the eponymous workplace of Pamela Ronald, professor of plant pathology and co-author with her husband, Raoul Adamchak, of Tomorrow's Table: Organic Farming, Genetics, and the Future of Food. It was becoming clear that maintaining Earth's current population—much less increasing it—would require a second green revolution, and that this next revolution could not draw on the same finite resources as had the first. Scientists must now figure out how to do more with less, and that figuring was going on here, in Professor Ronald's genetics laboratory.