Ammonia Synthesis – The double-edged sword

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From France’s Nicolas Sarkozy to America’s President-elect Barack Obama world leaders are pointing to investment in emerging green technologies and research as the way ahead in boosting the world’s sagging economy and creating new jobs, suggesting programs equivalent to U.S. President Franklin Roosevelt’s New Deal of the 1930s. But as the call goes out for green innovation and climate change technologies, there is an important lesson to learn from an ammonia synthesis patent which marks its 100^th anniversary this year: some inventions may be a double-edged sword. 

Fritz Haber filed a German patent in 1908 for the synthesis of ammonia for which he won a Nobel Prize in Chemistry in 1918. It was a truly breakthrough invention; Haber discovered how ammonia, a chemically reactive, highly usable form of nitrogen, could be synthesized.¹ Naturally nitrogen-rich soil is prime agricultural land due to its high productivity, but the nitrogen is depleted with each harvest, lowering the yield of farmlands year after year. A means of restoring nitrogen to soil would lead to a continuous, bountiful crop. Our atmosphere is 78 percent nitrogen, but it exists in a chemically and biologically unusable form. Thanks to Haber’s discovery cheap nitrogen became readily-available and easily usable as a fertilizer. Ammonia synthesis exponentially increased harvests and will continue to do so for years to come. His invention is credited with saving millions of lives and will probably save billions more.

But nitrogen has another application: it is the key ingredient in the explosive TNT (Trinitrotoluene). In his Nobel Prize acceptance speech, Haber only mentioned the growing demand for food as his motivation, but he was well aware of the invention’s other application. Following his discovery of ammonia synthesis, he had spent World War I working on poison gas research, earning the title “father of chemical warfare.” Haber’s ammonia synthesis invention cuts both ways; it has contributed to saving lives of millions but also to the deaths of millions.

Moving forward one hundred years and even the positive application of ammonia synthesis has repercussions. Haber could not have foreseen “the cascade of environmental changes, including the increase in water and air pollution, the perturbation of greenhouse-gas levels and the loss of biodiversity that was the result from the colossal increase in ammonia production and use that was to ensue.”² However, nitrogen fertilization will not be abandoned any time soon. The world’s population is expected to grow to 9 billion by 2042, and further increase our dependence on nitrogen fertilizers. A number of different scenarios for future nitrogen fertilizer use and the challenges likely to be faced by what has been called “our nitrogen economy” over the next hundred years are discussed in the article, “How a century of ammonia synthesis changed the world,” published in the September 28, 2008, issue of Nature Geoscience.

Who would really want to judge whether the benefits of Haber’s invention outweigh the repercussions? Can we even envisage a future without it? Ammonia synthesis does not stand alone; many inventions have had both positive and negative applications in addition to contributing to air, ground and water pollution. Policymakers, researchers and innovators are dedicated to finding climate change technologies that will not cause further damage to the planet.

By Sylvie Castonguay, WIPO Communications and Public Outreach Division.