In 2011, the earth’s population reached 7 billion. Since 1950, that number increased by 4.5 billion1. That’s four and a half billion additional mouths to feed and lives to support. As our population grows, our demand for resources increases. Scientists are hard at work developing new technologies to keep pace with rapidly decreasing supplies of resources – but how, in 61 years, could the world have supported the growth from 2 and a half billion to 7 billion people?
The answer – we simply have more food to go around. Our crops and agricultural practices have become more efficient and as a result, they can support more of us. In fact, half of us are alive2 because of the works of two innovative chemists: Carl Bosch and Fritz Haber. If not for them, the world population would stand at 3 and a half billion people today. Together, they developed one of the most valued inventions in history: the Haber-Bosch process2.
To explain this process, we need to know a bit of chemistry. The atmosphere is made up of 78% nitrogen. However, this atmospheric nitrogen is unusable by most life on earth4. Although bacteria in the soil naturally convert ammonia to nitrate, the scale at which it does so can certainly not support 7 billion people2. Fortunately, the Haber-Bosch process can be used on a large scale and converts the unusable atmospheric nitrogen into ammonia, a usable form of nitrogen. Ammonia is then converted into ammonium nitrate to be used in fertilizers for our crops. The additional nitrate available for plants to take up results in a higher crop yield. Thus, we now have the ability to feed our fellow 7 billion inhabitants, although we do so quite inequitably2.
Here lies the paradox of the Haber-Bosch process. The use of nitrogen-based fertilizers, which half of the human population can thank for their very existence, has detrimental consequences. Reduced biodiversity, harmful effects on human health, and accelerated global warming are only few of the many devastating consequences resulting from the process that ultimately keeps us alive. Our survival is leading to our deterioration.
Firstly, biodiversity has been compromised as a result of reduced oxygen in lakes and oceans, which itself is an indirect effect of fertilizer overuse. Nitrogen compounds reach water bodies through runoffs from farms. The excess nitrogen is a good source of fuel for algal blooms. However, as the algae use this and grow out of control, it reduces the amount of oxygen available to support other aquatic life3. These zones of hypoxia are called “dead zones”. Not only do these zones of little aquatic life disturb the ecosystem by taking away food sources from mammals and birds, they can also have adverse effects on human health. For instance, shellfish feed on the pathogenic microbes that invade algal blooms which in turn can make humans who consume the shellfish very ill6.
Moreover, in the 1940s, physicians started diagnosing rural infants with methemoglobinemia (a condition where the blood has a poor ability to carry oxygen). As it turns out, fertilizers containing the synthetically created nitrate were leaching into the ground water and eventually into community aquifers. Thus, bottle fed infants were prone to consuming water with high nitrate levels, which triggered methemoglobinemia3.
In addition, bacteria in nature use the nitrogen-compounds present in fertilizers to produce large amounts of nitrous oxide. Not only does nitrous oxide destroy ozone in the stratosphere that protects us from harmful UV rays, but it is also an extremely potent greenhouse gas, trapping 300 times more heat per molecule than does carbon dioxide2. In addition to its contribution to climate change, nitrous oxide is also a major contributor in creating smog. Smog is known to trigger asthma attacks, aggravate chronic lung diseases (e.g emphysema and bronchitis), and damage the lining of the lungs5.
In an attempt to mitigate these delayed consequences of the Haber-Bosch process, the UNEP (United Nations Environment Programme) proposed the idea of “20:20 for 2020”. The goal of the proposal is to increase the efficiency of nitrogen use by 20%, while decreasing the annual use of nitrogen by 20 million tons by the year 20202.
In order to achieve this goal, UNEP suggests that farmers be provided tools to measure their nitrogen efficiency which will allow them to use nitrogen based fertilizers more efficiently. For example, using little ploughing, controlling soil erosion, and planting winter cover crops, are a few ways to reduce nitrogen loss2. It is also suggested that we, as a global community, reduce the consumption of livestock fed crops grown with nitrogen fertilizers2.
However, given that the world population could reach 10.5 billion by 20502, reducing global consumption of agricultural products is an unreasonable goal to reach 2. It seems as though improving the efficiency of nitrogen fertilizers is the most reasonable solution to counter the effects of the Haber-Bosch process. However, even this is quite ambitious. Farmers depend on fertilizer use for their livelihood and under-application can have huge costs – in terms of profitability, over-applying is safer than under-applying2.
And so it stands that one of the world’s most influential innovations is causing unprecedented consequences. Awareness is a fundamental step towards a healthier planet. An informed society will allow for the development of initiatives, campaigns, and additional research directed at reducing the harmful effects of synthesized nitrogen and developing new ways to feed our rapidly growing planet. Since there is a vast range of agricultural practices, lifestyles, and values, one single solution will not supplement the Haber-Bosch process. Instead, we need to develop context-specific alternatives7. However, those working with nitrogen products, such as farmers, play a critical role in reducing the harmful effects of the Haber-Bosch process. It is crucial that awareness within this group be made priority. The power to improve nitrogen efficiency lies with them. Nevertheless, one question remains: is it even possible to support a vast and growing population while retaining our health and our environment’s health, or must we make a sacrifice to live?
1. United Nations. (2004). Projections to 2050. In World Population to 2300. New York: United Nations.
2. Mingle, J. (2013, March 12). Carl Bosch is Why You Are Alive and the Gulf of Mexico Isn’t.
3. Gorman, H. (2013). Learning from 100 Years of Ammonia Synthesis: Establishing Human- Defined Limits through Adaptive Systems of Governance. Gaia, 22(4), 263-270.
4. Nitrogen Cycle. (2013). Retrieved from http://environ.andrew.cmu.edu/m3/s4/cycleNitro.shtml
5. Smog – Who Does it Hurt? (1999). Retrieved from http://www.epa.gov/airnow/health/smog.pdf
6. Dead zone. (n.d.). Retrieved from http://education.nationalgeographic.com/education/ encyclopedia/dead-zone/?ar_a=1