The Process that feeds the world… and pollutes it

 July 31, 2013 

By Doug Struck
Globe Correspondent
Journalists love anniversaries, some more obscure than others. This year, we can celebrate the 100th anniversary of the first successful industrial use of the Haber-Bosch process.

We knew you had it circled in your datebook.

Little-known, granted, but important. The Haber-Bosch process of creating ammonia from air probably creates much of every meal you eat. It is by some calculations responsible for half of the protein in your body. It is the reason we can (more or less, depending on income) feed seven billion people on the earth. And, by some accounts, it is one of the big reasons our climate is rapidly changing for the worse.

haber.jpgFritz Haber was a German chemist who figured out how man could do what nature does – wrest nitrogen from the atmosphere.

Nitrogen is necessary for plants to grow, and it is everywhere around us in the air. But nitrogen is not easily gotten; nature has evolved a complex web of bacteria living at the roots of some plants to convert the nitrogen from atmosphere. This “fixed” nitrogen is then used by the plants use to create amino acids. Animals eat the plants, get the amino acids and create life-building proteins.

The scale of that process – and natural sources of nitrogen from saltpeter and guano– is limited worldwide, and that limit would restrict our food production to an amount that would feed no more than 3 or 4 billion people, half our population now.

But Haber teamed up with Carl Bosch to figure out how to create ammonia from hydrogen and the nitrogen in air, using massive boilers to super-heat the air under very high pressure. Their process, first used at a German industrial plant in 1913, eventually created an explosion of ammonia-based fertilizer, leading to the “Green Revolution” and a dramatic increase in the world’s food production.

Haber and Bosch each received the Nobel Prize. But their work was not all altruistic. The ammonia that began flowing out of their factories was an essential ingredient for explosives for Germany, prolonging World War I and boosting World War II. Haber helped create chemical weapons and the poison gas used in Nazi extermination camps. The Nobel Prize for his contribution to agriculture may have saved him from being branded a war criminal after World War I.

Still, the invention arguably forestalled a collapse of humanity from overpopulation, and is responsible for our cheap food today. But the legacy of their work has left two conundrums for mankind. First, many believe we have maxed out on the increased food production we can achieve from fertilization. That leaves the question of how we will continue to feed the world as it zooms toward 9 or 10 billion people. Some look to genetic modification to create the next Green Revolution in agriculture; others warn GMOs are a dangerous and unknown genie best left bottled.
Second, the fossil fuel used to create today’s annual use of 225 million tons of fertilizers inspired by Haber-Bosch, and to transport them and to apply them on agricultural fields, is immense. According to the Intergovernmental Panel on Climate Change, agriculture is responsible for at least 20 percent of the world’s greenhouse gas emissions. Overuse of nitrogen has chemically stripped our soils and left massive water pollution problems: it is the cause of the “dead zones” in rivers and seas.

When the world finally breaks its dependence on fossil fuels as the climate hurdles through now-inevitable tipping points, we will have to find other ways to grow our food. So as you eat your greenbeans tonight, a tip of the fork to Haber and Bosch. It was good while it lasted.