CHAPTER 31

Fritz Haber: the horror story of the man who invented poison gas

Fritz Haber, the German scientist who won the Nobel prize for the Haber-Bosch process which ‘made bread out of air’, was also the mastermind behind industrially killing enemy soldiers with chlorine gas in the trenches of World War One. This piece traces his extraordinary and infamous contributions to chemistry and mankind. 

Michael Gove, Nick Clegg, and Boris Johnson have fired the opening salvos in the 2014 political battle for the moral high ground over the First World War. But for all their ire and passion, it is an intellectually sterile, formulaic, and redundant debate.

No soundbite stereotypes can adequately package the brain-numbing complexity of the escalation of World War One, or the varying sentiments of those who suffered four years of industrialized death on barbed wire and icy ocean floors.

But the tub-thumpers will not be deterred, I am sure. We will see a lot more of this type of silliness as the year unfolds. Let’s hope we get some more interesting analysis from other quarters.

For example, what about the role of scientists in World War One? This comes to mind, as today marks the anniversary of the death of one of the best known of them: the physical chemist Fritz Haber—a man who put his deep scientific learning to work in the cause of killing.

It’s an inescapable fact that wars are fought with technology. From Greek fire and longbows to the payload of the Enola Gay and unmanned drones, the military has always demanded innovative science.

Scientists and engineers fight wars as surely as armed forces. From the quiet hum of their laboratories and workshops, they develop everything from military food rations and armour to field medicine, weapons, and munitions.

With the occasional exception—like Bishop Durand of Albi, who invented a fast-repeating trebuchet for attacking the Cathars of Montségur in 1244—we do not know a lot about who invented weapons back in the mists of time.

But nowadays we have names, and individual scientists are fully credited with their contributions to warfare.

For instance, Louis Fieser developed napalm for the US military. Oppenheimer and the others of the Manhattan Project were tasked with making the nuclear bombs that eventually laid waste to Hiroshima and Nagasaki. And Sir Barnes Wallis was engaged to perfect the first 6- and 10-ton bunker-busters, as well as bouncing bombs to take out the Ruhr valley dams in Operation Chastise.

Scientists have been at the heart of warfare and their contributions have often been decisive. As Sir Ian Jacobs, Churchill’s wartime military secretary, famously remarked on the influx of refugee scientists (including 19 Nobel laureates), ‘the Allies won the World War Two because our German scientists were better than their German scientists’.

Science is now, irreversibly, the handmaiden to war.

It is impossible to conceive of a militarized nation that does not pour money into scientific weapons research. (This is especially interesting in a Dawkins-esque context, in which one of the reasons given for science’s inherent superiority over religion is that religion is labelled as history’s chief facilitator of war.) As Oppenheimer mused in July 1945 after overseeing the first ever nuclear test explosion in New Mexico, ‘I am become death: the destroyer of worlds’.

Science can be used for good or ill. And today marks the death, 80 years ago, of a man who lived that choice more starkly than perhaps anyone else in the twentieth century.

In the early 1900s, Europe was running into serious problems fertilizing its crops. The vast shipments of bird droppings from South America were drying up, and there was no obvious alternative.

Enter the extraordinary physical chemist, Fritz Haber.

He was born on the 9th of December 1868 in Breslau (now Wrocław, Poland), and studied first at Heidelberg under Bunsen (of Bunsen Burner fame), then in Berlin. Once qualified, he worked in Zurich, Jena, and Karlsruhe, before finally settling back in Berlin-Dahlem.

Knowing that the air around us is 78.09 per cent nitrogen by volume. Haber discovered that it could be ‘fixed’ with hydrogen using high pressure, medium temperature, and a catalyst. The result was synthesized ammonia, from which fertilizer could be made.

It was one of the most significant scientific discoveries in modern history. Together with Carl Bosch from the chemicals giant BASF, he perfected the Haber-Bosch process, and they rolled it out at the BASF plant in Ludwigshafen.

The direct impact on the world’s ability to fight famine and feed itself was staggering. In 1900 the global population was 1.6 billion. It is now 7.2 billion thanks, in large part, to Haber and Bosch, who ‘made bread out of air’ as the publicity of the day said. Today, it is estimated that more than 50 per cent of the nitrogen atoms in the average human body derive from the Haber-Bosch process.

In recognition of his pioneering work, Haber received the 1918 Nobel Prize for chemistry (awarded in 1919).

Last November saw the one hundredth anniversary of the launch of the Haber-Bosch process, and scientists from all over the world gathered in Ludwigshafen to assess its extraordinary legacy.

But nothing comes at zero cost, so as well as celebrating the science of Haber-Bosch, the delegates also looked openly at the damage it had done. Not only is there the immediate environmental impact of a global population of over 7 billion humans, there are also the direct consequences of pouring and pumping unprecedented amounts of nitrates into the earth’s water and air.

That said, a hundred years ago, Haber could not have foreseen these consequences. He can have had no inkling of the environmental impacts of his discovery.

One choice he did have to make, though, was in relation to his country’s war effort, which badly needed nitrates for explosives. But it was a simple decision for him—a patriot—to allow his process to be militarized so Germany could again fill its empty cartridge cases and bombs.

So neither of these issues were direct ethical choices he had to make about scientific innovation.

The one that was put before him (or, rather, that he gave himself), was whether or not to use his knowledge and intellect to take a major scientific step towards mass industrialized killing.

And, without wavering, he did.

He can confidently be identified as the person who first suggested the battlefield use of clouds of air-dispersed chlorine gas as a weapon of mass destruction.

The idea got the green light, and he personally arranged and organized its deployment. On the 22nd of April 1915, he oversaw the opening of 6,000 cylinders of chlorine gas at Ypres, awaking the world to a new terror.

In less than 10 minutes on a Belgian Spring day, 1,000 French and Algerian soldiers lay dead, with a further 4,000 wounded.

Haber kept going. Over the course of the month, he released 500 tons of the fatal gas.

His wife, Clara Immerwahr, was also a gifted chemist—the first woman to be awarded a PhD from the University of Breslau. However, unlike her husband, she was a pacifist. Despite Fritz’s belief that death by gas was no worse than any other form of wartime killing, his guiding hand in the chemical carnage of the trenches destroyed her.

When he returned triumphantly home after Ypres to celebrate his promotion to Captain, she challenged his work. Unable to sway him, and overwhelmed with shame, she took his service revolver and shot herself. The next day, Fritz abandoned his grieving 13-year-old son, Hermann, and returned to the front line and his gas deployments, this time in the East against the Russians. (Years later, aged 44, Hermann also committed suicide at the shame of his father’s work.)

Although the battlefield use of poison gas was manifestly in breach of international treaty obligations, the genie was out of the bottle, and all sides now piled in. Back in Germany, Haber was promoted to head the Chemical Warfare Service.

To be fair, Haber had not started the battlefield gas attacks in the World War One. That honour goes to the French, who first deployed tear gas (xylyl bromide), leading to an escalation. But Haber’s unique, early, and defining contribution to trench warfare was to up the ante, replacing irritant gases with fatal clouds of WMDs.

After so long, it is hard to know what really motivated Haber. His claim that he believed chemical attacks would bring the war to a speedy and decisive end does not explain why he kept at it for years, long after it was clear that there would be no swift and immediate resolution.

There is a suggestion that his zeal lay in an unusually strong love of his country as he was, along with most of Europe in the early 1900s, fervently patriotic. In the face of rising anti-Semitism, he had even become a Christian to deepen the Germanness he felt so passionately. This intense nationalism is the usual explanation for his willing contribution to the war effort—but it seems a little simplistic. Many people love their countries profoundly without developing weapons of mass destruction. Maybe his mother’s death while giving birth to him affected him in ways that no one diagnosed in the late 1800s and early 1900s. We shall probably never know.

After the war, he continued trying to use science to assist his country. Conscious of the crippling reparations imposed by the Treaty of Versailles, he set about trying to extract gold from seawater to help Germany pay the impossibly unrealistic fines. To his intense frustration, he failed.

All the while, he continued his work on toxic gases. Then, one morning in 1933, his world collapsed when he was refused admission into the Berlin Institute he oversaw. Despite having changed his religion years earlier, he had run foul of the new racial laws, and was no longer welcome.

Broken, he left the country he idolized.

Ironically, a scientist at Cambridge University offered him a laboratory. Haber duly came to England. Although he was pleased to be working again, he soon found the damp weather aggravated his health. He left, and died the following year in Switzerland en route to British Palestine. He therefore did not live to witness what use was made of Zyklon B, a hydrogen-cyanide-based gas product he had been developing. Neither did he see how many members of his own immediate family were killed with it.

To put Haber into the context of his time, he was by no means the only scientist willing to develop chemical WMDs. If he had not done it, the chances are someone else would, and that person could just as easily have been from one of the other combatant countries. As it was, in 1915, the governments of France, England (and eventually the US) all managed to find their own willing scientists to brew up a variety of horrific lethal killing smogs.

What had started with exchanges of chlorine soon moved on to phosgene, and eventually mustard gas. The British army even had dedicated Royal Engineer Special Gas Companies in charge of deploying the chemical weapons on the battlefield. All sides worked hard at the technology. Take William Livens, for instance, an English soldier and engineer (Oundle and Cambridge) who vowed to exterminate as many of the enemy as he possibly could. His successes included chemical mortars, flame fougasses, and petroleum throwers that filled enemy trenches with flaming oil.

In any event, by the end of World War One, after all sides had gone resolutely chemical, over 124,000 tons of military gas had been produced, resulting in an estimated 90,000 deaths and 1.3 million casualties.

These deaths were all, technically, in breach of international treaty obligations banning the use of battlefield poisons and gases, but war is war—and the niceties of international law are often left for the victors to pick over afterwards.

It is, though, odd that Haber should have been awarded a Nobel Prize. Odd because Alfred Nobel specifically instituted the prize to polish up his own reputation, tarnished from a lifetime of developing explosives. Having one day seen his premature obituary in a French newspaper under the banner, ‘Le marchand de la mort est mort’ (The merchant of death is dead), he decided to work on his legacy by instituting a prize to celebrate the best in human achievement.

Haber’s work on synthesizing ammonia was a singular accomplishment. If the Nobel Committee had presented him a prize in 1913 when he first made his nitrogen fixation breakthrough, he would have been warmly applauded.

But in 1918, with the world’s most horrific war drawing to a close, Fritz Haber was identifiably the man most directly responsible for unleashing one of its defining terrors:

Gas! Gas! Quick, boys!—An ecstasy of fumbling,

Fitting the clumsy helmets just in time;

But someone still was yelling out and stumbling,

And flound’ring like a man in fire or lime …

Dim, through the misty panes and thick green light,

As under a green sea, I saw him drowning.

(Wilfred Owen, Dulce et Decorum Est, 1917)

An award like the Nobel Prize survives on the quality of its laureates. Perhaps in recognition of this, of the 1,380-word biography of Fritz Haber on the Nobel Prize website, only one sentence mentions his work on poison gases.

Large numbers of diplomats and scientists boycotted his award ceremony in Stockholm. They were not disputing that he was a gifted scientist. But he made choices. And they were ones that many people did not agree with.

Rewarding infamy is a dangerous precedent. I rather suspect that had Alfred Nobel been looking down at the award presentation, he would have agreed with the nays. For all his genius, in 1919 Fritz Haber could not really be said to rank among those who ‘have conferred the greatest benefit on mankind’.