Hunger For Natural Gas

Two Gulf hurricanes and the approaching winter in the Northern Hemisphere have kept natural gas futures hovering near all-time highs. But with the accelerating depletion of reserves in North America, the intermittent gas crises we've been seeing since 2001 will start coming thicker and faster, finally merging into an era of permanent scarcity.

A chronic gap between supply and demand would mean plenty of hardship in the United States and Europe, which have come to rely on natural gas not only for heat, but increasingly for electricity generation and manufacturing. But the future looks even more grim in the global South, where the maintenance of human life itself has come to depend on the steady and reliable supply of natural gas that's needed to synthesize nitrogen fertilizer for food production.

Turn off the gas, and a lot of American families would have a hard time cooking dinner -- but a lot of families in places like Nepal and Guatemala would have nothing to cook.

Nitrogen and human existence

Crop plants assemble carbon, hydrogen, oxygen and nitrogen into proteins that are essential both to plant growth and to the diets of humans and other animals. Of those four elements, nitrogen is the one that's too often in short supply. If you see yellowish, stunted crops, whether they're in an Indiana cornfield or an Indonesian rice paddy, it's likely that you can blame it on a lack of nitrogen.

A world of 6.4 billion people, on the way to 9 billion or more, needs more protein than the planet's croplands can generate from biologically provided nitrogen. Our species has become as physically dependent on industrially produced nitrogen fertilizer as it is on soil, sunshine and water. And that means we're hooked on natural gas.

Vaclav Smil, distinguished professor at the University of Manitoba and author of the 2004 book Enriching the Earth: Fritz Haber, Carl Bosch and the Transformation of World Food Production, has demonstrated the global food system's startling degree of dependence on nitrogen fertilization. Using simple math -- the kind you can do in your head if there's no calculator handy -- Smil showed that 40 percent of the protein in human bodies, planet-wide, would not exist without the application of synthetic nitrogen to crops during most of the 20th century.

That means that without the use of industrially produced nitrogen fertilizer, about 2.5 billion people out of today's world population of 6.2 billion simply could never have existed.

If farming depended solely on naturally occurring and recycled nitrogen fertility, the planet's cropped acreage could feed only about 50 percent of the human population at today's improved nutrition levels, according to Smil. But absolute dependence on synthetic nitrogen is geographically lopsided -- it's largely in countries with a high human-cropland ratio that survival hinges on nitrogen fertilizer. This includes India, Indonesia, and China, where four in 10 human beings on Earth reside.

In contrast, those countries lucky enough to have ample cropland and relatively low population density could survive on far less synthetic nitrogen than they currently use.

The nation that ranks as the world's third biggest nitrogen fertilizer consumer could, conceivably, get by without the stuff. If that country, the United States, were to moderate its meat consumption, raise all livestock on pasture and rangeland instead of nitrogen-wasting grains, rely more on legume crops (plants like beans and alfalfa that obtain nitrogen from the air with the help of bacteria), curb waste and cut food exports, it could maintain its food supply without using any synthetic nitrogen at all, according to Smil's calculations.

The momentum of past population growth is expected to add two to four billion people to the world's population by 2050, even with concerted efforts to rein in growth. Almost all of the increase will occur in Africa, Asia, Latin America and the Middle East. That will double the demand for nitrogen fertilizer in those regions, and by that time, says Smil, 60 percent of their inhabitants will depend existentially (in the literal sense, not the philosophical one) on natural gas-derived nitrogen fertilizer.