The World Without Us

In a world without humans, a screeching halt to all artificial farmland fertilization would take instant, enormous chemical pressure off the richest biotic zones on Earth—the areas where big rivers bearing huge natural nutrient loads meet the seas. Within a single growing season, lifeless plumes from the Mississippi to the Sacramento Delta, to the Mekong, Yangtze, Orinoco, and the Nile, would begin to shrink. Repeated flushings of a chemical toilet will steadily clarify the waters. A Mississippi Delta fisherman who awakened from the dead after only a decade would be amazed at what he’d find.

4. The Genes

Since the mid-1990s, humans have taken an unprecedented step in Earthly annals by introducing not just exotic flora or fauna from one ecosystem into another, but actually inserting exotic genes into the operating systems of individual plants and animals, where they’re intended to do exactly the same thing: copy themselves, over and over.

Initially, GMOs—genetically modified organisms—were conceived to make crops produce their own insecticides or vaccines, or to make them invulnerable to chemicals designed to kill weeds competing for their furrows, or to make them—and animals as well—more marketable. Such product improvement has extended the shelf life of tomatoes; spliced DNA from Arctic Ocean fish into farmed salmon so that they churn out growth hormones year-round; induced cows to give more milk; beautified the grain in commercial pine; and imbued zebra fish with jellyfish fluorescence to spawn glow-in-the-dark aquarium pets.

Growing more ambitious, we’ve coaxed plants that we feed to animals to also deliver antibiotics. Soybeans, wheat, rice, safflower, canola rapeseed, alfalfa, and sugarcane are being genetically hot-rodded to produce everything from blood thinners to cancer drugs to plastics. We’ve even bio-enhanced health food to produce supplements like beta carotene or gingko biloba. We can grow wheat that tolerates salt and timber that resists drought, and we can make various crops either more or less fertile, depending on which is desired.

Appalled critics include the U.S.-based Union of Concerned Scientists, and approximately half of Western Europe’s provinces and counties, including much of the United Kingdom. Among their fears is what we might do to the future, should some new life-form proliferate like kudzu. Crops such as Monsanto’s suite of “Roundup Ready” corn, soy, and canola—molecularly armored to shrug off that company’s flagship herbicide while everything else nearby dies—are doubly dangerous, they insist.

For one, they say, sustained use of Roundup—a trade name for glyphosate—on weeds has simply selected for Roundup-resistant strains of weeds, which then drive farmers to use additional herbicides. Second, many crops broadcast pollen to propagate. Studies in Mexico that show bio-tinkered corn invading neighboring fields and cross-pollinating natural strains have provoked denials and pressure on university researchers by the food industry, which underwrites much of the funding for expensive genetic studies.

Modified genes from commercially bred bentgrass, a turf used on golf courses, have been confirmed in native Oregon grasses, miles from the source. Assurances from the aquaculture industry that genetically supercharged salmon won’t breed with wild North American stock, because they’re raised in cages, are belied by thriving salmon populations in estuaries in Chile—a country that had no salmon until breeders were imported from Norway.

Not even supercomputers can predict how man-made genes already loosed upon the Earth will react in a near infinity of possible eco-niches. Some will be roundly trounced by competition toughened over eons by evolution. It’s a fair bet, though, that others will pounce on an opportunity to adapt, and evolve themselves.

5. Beyond the Farm

Rothamsted research scientist Paul Poulton stands in November drizzle, knee-deep in holly, surrounded by what will be around after human cultivation ceases. Born just a few miles up the road, lanky Paul Poulton is as rooted to this land as any crop. He started working here right out of school, and now his hair has whitened. For more than 30 years, he’s tended experiments that began before he was born. He’d like to think they will continue on long after he himself turns to bone dust and compost. But one day, he knows, the wild green profusion beneath his muddy irrigation boots will be the only Rothamsted experiment that will still matter.