Nitrogen! Nitrogen! Sis Boom Bah!

I let a reference to nitrogen pass the other day without expounding on it at all, something a truly committed nerd would never do. So in the interests of retaining my Member in Good Standing status at the local chapter of the Obnoxious Geeks of America society, I’m here to make up for the lapse.

At first glance you might be tempted to think that writing a post in celebration of nitrogen is like composing a musical in praise of zinc. But in fact nitrogen is nowhere near as esoteric a thing. It is in fact one of the essential building blocks of life on Earth, without which nothing could grow or reproduce. So what, brainiac, you can say the same thing about lots of elements…oxygen for example. Ah, but there’s an important difference, for while our planet abounds in biologically useful oxygen, there’s a very limited supply of naturally-occurring nitrogen that living organisms can use.

The great irony of nitrogen (get it? iron-y? ha!) is that while it’s the single most abundant element in the Earth’s atmosphere, plants and animals can’t use it in its pure form. Taking in pure nitrogen either by breathing it or eating it is on par with trying to increase your iron intake by eating nails. The body simply can’t assimilate it. It has to be converted into usable nitrogen-based compounds (i.e. “fixed”) before it can be used to make critical things like amino acids and proteins. In nature nitrogen fixation (and no that’s not a psychological disorder I’m suffering from) is mostly accomplished by bacteria in what’s known as the nitrogen cycle, that thing that made your eyes glaze over in junior high science class. The trouble is, naturally occurring bacteria can’t possibly produce enough nitrogen to sustain an ever-growing population of life on Earth. Without the fundamental chemical building blocks needed to create life, there can only be so much life. It’s that simple.

This fact was in no way lost on scientists around the turn of the last century, who realized that one and a half billion people (the population of the Earth at the time) were in serious danger of using up the Earth’s limited supply of fixed nitrogen. Were that to happen, mass starvation, disease and death would surely follow.

Enter a fellow by the name of Fritz Haber, a brilliant German-Jewish chemist who was tasked with finding a way to fix nitrogen so that Germany could continue to fight World War I. Did I forget to mention that fixed nitrogen is also a critical component of explosives? Oops, yes. The fact that nitrogen releases huge amounts of energy when it’s burned is how Timothy McVeigh brought down a building with a truckload of fertilizer. Up until the middle of the war, Germany had imported most of its nitrogen from Chile in the form of saltpeter (potassium nitrate) which it used to make bombs. As the war wore on those supplies were increasingly cut off, to the point that an alternative had to be found. In 1908 Fritz Haber found that alternative, and two years later a fellow by the name of Carl Bosch refined it to create what has become known as the Haber-Bosch Process.

When asked what the most important inventions of the 20th century were, most people cite things like the automobile, television and computers. However none of them have done so much to impact the quality — and quantity — of life on Earth as the Haber-Bosch Process. That technology (which rapidly spread to other developed countries following the war) went on to enable the development of nitrogen fertilizers which, for all their faults, have not only staved off mass starvation on our planet, have allowed its population to grow to over 6 billion.

Of course there were down sides to the invention of fixed nitrogen too, significant ones. There are the explosives I mentioned, dynamite and TNT, but also cyanide gas, which, in an especially ironic twist for a German Jew like Fritz Haber, turned out to be the main component of Zyklon B, the compound used to exterminate millions of Jews in concentration camps during World War II. And in fact there are people out there who make the grim calculus that had it not been for Haber and his invention, World War I could never have been maintained, which means World War II might never have been fought, which means that 70 million people wouldn’t have been killed. I find that sort of reasoning puerile in the extreme. Had Haber not invented nitrogen fixation, somebody else surely would have. And anyway, even if you grant that fixed nitrogen was responsible for killing 70 million people (though I personally won’t), it’s prevented the starvation of countless millions, and allowed billions of us to be born.

Of course there are plenty of people around these days who would call that a bad thing too. To whom I can only say, take it up with your great-grandmother. For had she not been the beneficiary of a steady supply of bioavailable nitrogen thanks to the Huber-Bosch process, you wouldn’t even be here.

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