At first glance, nitrogen seems like one of the least interesting elements on Earth. It makes up about 78 percent of the air we breathe, yet for most of human history it was paradoxically scarce in the one place it mattered most: food. Plants cannot use atmospheric nitrogen directly, and without nitrogen-rich soil, crops fail. The story of the Haber-Bosch process is the story of how humanity learned to unlock this vast atmospheric reservoir and, in doing so, fundamentally changed agriculture, population growth, and even global politics.
Before the twentieth century, farmers relied on natural sources of usable nitrogen such as manure, compost, crop rotation with legumes, and limited mineral deposits like Chilean saltpeter. These methods worked, but only up to a point. As populations grew during the Industrial Revolution, many scientists feared a looming agricultural collapse. Yields were rising too slowly to feed expanding cities, and natural nitrogen sources were finite. Some experts openly predicted widespread famine in Europe within decades.
The breakthrough came from chemistry. In 1909, the German chemist Fritz Haber demonstrated that atmospheric nitrogen could be combined with hydrogen to form ammonia under conditions of high temperature and pressure, using a catalyst. Ammonia is rich in nitrogen and can be converted into fertilizers that plants readily absorb. On paper, the reaction looked simple. In practice, it was brutally difficult to control and sustain.
Turning Haber’s laboratory discovery into an industrial reality fell to Carl Bosch, an engineer working at BASF. Bosch solved the enormous technical challenges involved: designing steel reactors that could withstand extreme pressures, finding durable catalysts, and building systems capable of running continuously rather than in short experimental bursts. By 1913, the first industrial Haber-Bosch plant was operating, producing ammonia on a scale the world had never seen.
The consequences were immediate and profound. Synthetic fertilizers made from ammonia allowed farmers to replenish nitrogen in soils year after year, dramatically increasing crop yields. Wheat, rice, and maize production surged. Regions that once struggled to feed themselves became food exporters. Over time, this steady, reliable nitrogen supply supported explosive population growth. Today, it is estimated that roughly half of the global population depends on food grown with fertilizers derived from the Haber-Bosch process.
Less often remembered is the process’s darker side. The same ammonia used to make fertilizer can also be used to manufacture explosives. During World War I, Germany used synthetic ammonia to produce munitions after naval blockades cut off access to natural nitrate supplies. This dual-use nature of nitrogen fixation means the Haber-Bosch process has been deeply entangled with both life-saving agriculture and large-scale warfare.
There are also environmental costs that were not obvious at first. Excess fertilizer runoff contributes to water pollution, algal blooms, and oxygen-depleted “dead zones” in lakes and oceans. The process itself is energy-intensive and heavily dependent on fossil fuels, making it a significant source of carbon dioxide emissions. In many ways, the same technology that solved one global crisis helped create new ones.
Still, it is hard to overstate the importance of the Haber-Bosch process. It transformed nitrogen from a limiting factor into an abundant resource, reshaping ecosystems, economies, and human destiny. Modern research now focuses on making nitrogen fixation cleaner and more efficient, including alternative catalysts and biological methods inspired by nature. A century after its invention, the challenge is no longer how to fix nitrogen, but how to use it wisely.
Few scientific processes have had such sweeping and lasting effects. By pulling nitrogen out of thin air, humanity quite literally learned how to feed itself at planetary scale—and in doing so, changed the course of civilization.
