Feeding the world, poisoning the planet

NITROGEN'S DEADLY HARVEST

Without nitrogen fertilizer, many would starve. But nitrogen from runoff and fuel burning is building in waters around the globe, threatening ecological calamity.

  • Menace: Coastal algae blooms, such as this one in California, signal dangerously unbalanced water chemistry.
Menace: Coastal algae blooms, such as this one in California,… (Photo by Peter J.S. Franks:…)
September 24, 2000|By Tom Horton and Heather Dewar | Sun Staff

First of five articles

AASEN, Netherlands -- Leopold Hendrick admits a visitor through the locked doors of the world's first bureaucracy dedicated to tracking and taxing animal waste, a kind of manure IRS. The government administrator apologizes for the tight security: "We are not so popular. Some farmers broke in and tried to steal their dossiers."

Other nations should track plutonium so closely.

Dutch farmers must report to the nation's 340-employee Levy Bureau how much their 4.2 million cattle, 14 million pigs and 108 million chickens eat. They must inform the bureau of their farms' precise output, the meat and dairy products they ship away.

And especially, they must tell the bureau how much manure is left behind and what happens to each and every bit of it. Using bar-coded samples, computerized and cross-referenced to papers filed by haulers, the agency meticulously tracks the manure with a system worthy of high-level hazardous waste. The Netherlands, with the highest concentration of livestock anywhere, might simply be a few years ahead of the rest of the world in confronting the planet's next big wave of pollution woes. The culprit is way too much nitrogen, which in this case seeps from animal manure.

Holland's extraordinary efforts to control nitrogen dramatize the unprecedented imbalance that humans have wrought in Earth's basic chemistry as a result of the past half-century of overfertilization.

Nitrogen is one of the most common elements. A vital building block of all plant and animal tissue, it is concentrated in all human sewage and animal manure, in widely applied crop fertilizers and even in polluted air - all the products of human endeavors.

Humans "have altered nitrogen more than any other element," says Stanford University ecologist Peter Vitousek.

In just the past few decades, industrialization, population growth and intensive use of chemical fertilizers have doubled the amount of nitrogen in circulation among living things.

By contrast, human changes to atmospheric carbon dioxide - blamed for global warming - represent an increase of no more than 10 percent in Earth's natural supply, Vitousek says.

And this sudden explosion of nitrogen has meant mounting worldwide environmental problems that have already had lethal effects - problems that promise to soon get worse and, some scientists predict, to reach the point of calamity.

Increasing signs that the chemical balance of the planet is out of whack, either wholly or partly from an oversupply of nitrogen, are already apparent in virtually every corner of the world:

• Frequent, thick blooms of deadly algae in coastal areas, from Finnish beaches to Hong Kong harbors. During one such "red tide," fish farmers near the Chinese city took to the sea in their sampans in a desperate effort to literally turn back the toxic tide with their engines.

• Historic and once-teeming fishing waters now devoid of oxygen and life. Fully one-third of the water in the Chesapeake Bay turns lifeless most summers. In the Black Sea, once Russia's Riviera, 5 million tons of fish have suffocated in less than two decades.

• Drastic declines in underwater beds of sea grasses and critical coral reefs. In Australia, diver Ben Cropp bemoans the loss of "the viz" - the sparkling visibility - in parts of the Great Barrier Reef. A world away, Maryland biologist Mike Naylor maps the disappearance of grasses that nurture Chesapeake blue crabs.

• Widespread damage to far-flung grasslands and forests. Even in remote areas, from Minnesota to the Netherlands, the rain is so laden with fertilizer that it overwhelms delicate native plants.

• Suspected links to a variety of human health problems, from cancer to skin rashes, respiratory troubles to memory failure. When the toxic Pfiesteria microbe bloomed in nitrogen-laden rivers on Maryland's lower Eastern Shore in 1997, doctors documented a brand new illness. "Estuarine associated syndrome" has many symptoms, the main one a change in victims' brain function that leaves blanks in their memories.

Earth's growing overabundance of nitrogen is rooted in agriculture's desperate 10,000-year search for ways to boost crop yields, a dream not realized until the early 20th century when a new invention enabled humans for the first time to extract limitless amounts of this potent chemical from the air.

That epochal breakthrough, combined with growing amounts of nitrogen from fossil fuels burned in autos and industries, flooded our planet with one of nature's most powerful growth stimulants, upsetting the natural balance adapted over tens of millions of years to scant rations of fertilizer.

If the history of the planet were compressed into a single year, this enormous change occurred just 25 seconds before midnight on New Year's Eve.

While much of the impact is out of sight and, for many, out of mind, there's abundant scientific proof that too much nitrogen is creating environmental nightmares.

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