The Nitrogen Fix:
Breaking a Costly Addiction

Over the last century, the intensive use of chemical fertilizers has saturated the Earth’s soils, waters, and atmosphere with nitrogen. Now scientists are warning that we must move quickly to revolutionize agricultural systems and greatly reduce the amount of nitrogen we put into the planet's ecosystems.

by fred pearce

A single patent a century ago changed the world, and now, in the 21st century, Homo sapiens and the world we dominate have an addiction. Call it the nitrogen fix. It is like a drug mainlined into the planet’s ecosystems, suffusing every cell, every pore — including our own bodies.

In 1908, the German chemist Fritz Haber discovered how to make ammonia by capturing nitrogen gas from the air. In the process he invented a cheap new source of nitrogen fertilizer, ending our dependence on natural sources, whether biological or geological. Nitrogen fertilizer fixed from the air confounded the mid-century predictions of Paul Ehrlich and others that global famine loomed. Chemical fertilizer today feeds about three billion people.

But the environmental consequences of the massive amounts of nitrogen sent coursing through the planet’s ecosystems are growing fast. We have learned to fear carbon and the changes it can cause to our climate. But one day soon we may learn to fear the nitrogen fix even more.

A major international survey published in September in Nature listed the

Artificial nitrogen is as ubiquitous in water as man-made carbon dioxide is in the air.

nitrogen cycle as one of the three “planetary boundaries” that human interventions have disturbed so badly that they threaten the future habitability of the Earth. The others — according to the study by Johann Rockstrom, of the Stockholm Environment Institute, and 27 other environmental scientists – are climate change and biodiversity loss.

Nitrogen affects more parts of the planet’s life-support systems than almost any other element, says James Galloway of the University of Virginia, who predicts: “In the worst-case scenario, we will move towards a nitrogen-saturated planet, with polluted and reduced biodiversity, increased human health risks and an even more perturbed greenhouse gas balance.”

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