31. Why Should We Thank Neil Armstrong for Our Daily Bread?
The Green Revolution
On July 18, 1969, two days before Neil Armstrong and Edwin ‘Buzz’ Aldrin were the first humans to walk on the moon, the US president’s speechwriter penned the following words: ‘Fate has ordained that the men who went to the moon to explore in peace will stay on the moon to rest in peace’, began the speech that the president would read if the two astronauts could not return. ‘In ancient days, men looked at stars and saw their heroes in the constellations. In modern times, we do much the same, but our heroes are epic men of flesh and blood. Others will follow, and surely find their way home. Man’s search will not be denied. But these men were the first, and they will remain the foremost in our hearts. For every human being who looks up at the moon in the nights to come will know that there is some corner of another world that is forever mankind.’1
Fortunately, Richard Nixon was never required to read these solemn yet profound words. On July 20, Armstrong stepped onto the moon with his famous quip: ‘That's one small step for man, one giant leap for mankind.’ Four days later, the crew returned to Earth, signaling US victory over the Soviet Union in the Space Race and fulfilling President John F. Kennedy’s 1961 promise to land a man on the moon and return him safely before the decade’s end.
Yet despite the Space Race igniting global interest in humanity’s quest to settle other planets, it seemingly did little to alleviate the very immediate concerns about the future of life on earth. One book, published only a year before Armstrong walked on the moon, encapsulated this fear best. The opening statement in an early edition spelt out the imminent threat: ‘The battle to feed all of humanity is over. In the 1970s hundreds of millions of people will starve to death in spite of any crash programs embarked upon now. At this late date nothing can prevent a substantial increase in the world death rate...’2
The Population Bomb, written by Paul Ehrlich and Anne Howland Ehrlich, became an immediate bestseller. It brought unprecedented attention to food supply and, more importantly, policies at combating fertility. The Ehrlichs had their own proposals to defuse the bomb: ‘We must rapidly bring the world population under control, reducing the growth rate to zero or making it negative. Conscious regulation of human numbers must be achieved. Simultaneously we must, at least temporarily, greatly increase our food production.’3 It was Thomas Malthus, the eighteenth-century English cleric we discussed in Chapter 17, on steroids.
But, just as with Malthus, the Ehrlichs had it all wrong. Now, almost six decades after its publication, the world looks very different. The Population Bomb’s grim predictions came at exactly the time that global population growth rate, the difference between the number of people born and the number of people dying, was at its maximum. As it turns out, its predictions were dead wrong: the global annual crude death rate in 1968 was 13.52 per 1000 people, and in 2021 it was 8.76.4 Instead of widespread famine, disease and social unrest, the world experienced one of the most prosperous and peaceful periods in human history. Famines, such as those in the Horn of Africa, were often more the result of politics than production.
They were especially wrong about India. In The Population Bomb, the Ehrlichs wrote: ‘India couldn’t possibly feed two hundred million more people by 1980.’5 They went as far as to propose that aid should be cut off from India if they did not implement fertility control, a proposal that would have certainly created the conditions for famine. In April 2023, India surpassed the population of mainland China, a country that did take Ehrlich’s predictions to heart and enacted population control measures. While India is now the most populous country on earth, China has serious concerns about an ageing population.
But how could the Ehrlichs, and the many others who believed their thesis, get it so wrong? Innovation is again, just like in the time of Malthus, the driving force. Meet Norman Borlaug, a man you’ve probably never heard of but who is credited with saving millions of people – perhaps as many as a billion – with his inventions. Borlaug is considered the father of the ‘Green Revolution’, a period of agricultural innovation that involved the development and adoption of high-yielding varieties (HYVs) of staple crops like wheat, rice and maize. These HYVs were combined with modern agricultural practices such as the use of chemical fertilizers, pesticides and improved irrigation techniques, significantly increasing food production, particularly in developing countries.
The story starts in Mexico. Borlaug was a microbiologist for the chemical firm DuPont when he was invited to establish a Cooperative Wheat Research and Production Program in Mexico. He rejected DuPont’s offer to double his salary, and leaving his pregnant wife and 14-month-old daughter behind, flew to Mexico City in 1944 to head the new programme. The aim of the programme was for Mexican and US scientists to collaborate on soil development and plant pathology in order to boost wheat production in Mexico, which was importing most of its wheat at the time. Borlaug spent the first ten years breeding wheat cultivars resistant to diseases like rust, making 6,000 individual crossings of wheat. He developed the ’shuttle breeding" technique, utilising Mexico’s double harvest seasons to speed up breeding, which led to the creation of wheat varieties adaptable to different environmental conditions. By crossbreeding semi-dwarf Japanese wheat with his disease-resistant varieties, creating new varieties called Pitic 62 and Penjamo 62, Borlaug significantly increased wheat yields, leading to Mexico becoming self-sufficient in wheat production by 1963, with 95% of the country’s wheat crops using his high-yield, disease-resistant varieties. Mexico started exporting wheat, and its farmers, who only a few years earlier did not even know how to use fertiliser, were suddenly supplying other countries.
It was this exchange of HYVs that allowed Mexico’s success to be replicated elsewhere, particularly in Southeast Asia. Pakistan, for example, achieved self-sufficiency in wheat within three years, driven in part by its rivalry with India. It had placed its first major seed order less than a year after its archrival, India, embraced the Green Revolution. Between 1965 and 1972, new crop varieties more than doubled India’s wheat production, making it the world’s third-largest producer.
But just how important were these new crop varieties really? In a 2021 Journal of Political Economy paper, the economists Douglas Gollin, Casper Worm Hansen and Asger Mose Wingender exploit the fact that crops were (exogenously) developed and adopted at different times by different countries to identify the causal effect of Green Revolution crops.6 They estimate that HYVs increased yields, for a sample of 90 countries, by an average 44% between 1965 and 2010. They then do a best-case counterfactual analysis: What would have happened had the Green Revolution been delayed by a decade, for example, if Norman Borlaug had accepted DuPont’s salary offer and remained in the US with his pregnant wife? In such a scenario, the authors calculate, GDP per capita in 2010 would be 17% lower across all 90 countries, a massive effect.
And those numbers only estimate the effect of a delay. What if there never was a Green Revolution?
Our baseline estimates imply that aggregate food crop yields for our sample of countries would have been 49% lower in 2010 had the Green Revolution never happened. They would still have been higher than those in 1964, but the Green Revolution has accounted for as much as threequarters of yield growth since then. We find similarly large effects for GDP per capita, which would have been 51% lower in the counterfactual scenario. Taken at face value, this estimate means that the Green Revolution has been responsible for about half of total growth in GDP per capita in our sample period.7
In short, the Green Revolution is not just responsible for boosting farm yields and reducing the risk of famines but for propelling global living standards to levels unimaginable only a generation earlier. It is no wonder that Norman Borlaug was awarded the Nobel Peace Prize in 1970.
As with all inventors, Borlaug stood on the shoulders of giants. New crop varieties required fertilizer, and lots of it. While farmers had always understood the value of fertilizer, before the invention of the Haber-Bosch process by German chemists Fritz Haber and Carl Bosch in the first decade of the twentieth century, access to effective fertilizers was limited and costly. Consider one important source before the invention of Haber-Bosch: guano, the cemented deposits of bird (and bat) droppings.8 Although guano as fertilizer was not a recent invention – inhabitants of the arid Atacama Desert in Chile already used seabird droppings to grow maize more than a millennium ago9 – the industry would really take off in the mid-nineteenth century because of agricultural demand in Britain and the United States. Peru was the hub of the global trade. Its many coastal islands had rich guano deposits, so rich that it soon became the most important resource in the country: ‘So great is the value of this branch of the national riches’, wrote the Peruvian finance minister in 1858 of the guano trade, ‘that without exaggeration it may be affirmed that on its estimation and good handling depend the subsistence of the State, the maintenance of its credit, the future of its increase, and the preservation of public order’.10
Nineteenth-century Cape Colony farmers were also desperate for this ‘white gold’. They had two options: seabird guano, located on the rocky islands off the western coast as far north as Ichaboe Island on the Namibian coast, or bat guano, located in relatively inaccessible and geographically dispersed caves on the southern Cape coast.11 It would be the excessive guano-scraping of these islands by private companies that gave rise, towards the end of the nineteenth century, to government ownership and legislation to protect animals and birds, the first attempts to balance economic interests with conservation efforts in the region.
Using unsustainable guano harvesting as a source of fertilizer would not have made the Green Revolution possible. Indeed, the Haber-Bosch process, by which atmospheric nitrogen is converted to ammonia by a reaction with hydrogen, has been of ‘greater fundamental importance to the modern world than the invention of the airplane, nuclear energy, space flight, or television’, Vaclav Smi wrote in 2004. 12 ‘The expansion of the world's population from 1.6 billion people in 1900 to today's six billion would not have been possible without the synthesis of ammonia.’
Today, the world population is at almost 8 billion. It is predicted to peak in 2064 at 9.7 billion and decline to 8.8 billion by 2100.13 One obvious question is whether we can sustain such high population numbers – or will we, as the Ehrlichs predicted, finally run into food shortages?
Hidden within the paper by Gollin, Hansen, and Wingender is one surprising finding that may help to answer this question. They calculate the impact of HYVs on fertility. Did higher crop yields lead to larger families, as Malthus proposed two centuries ago?
They find the opposite result. Increasing crop yields reduced infant mortality (increasing population size) but lowered fertility (reducing population size).14 The latter effect was larger, however, meaning that higher crop yields not only allowed more children to survive into adulthood but also allowed more families the choice to have fewer children, lowering the natural population growth rate.
The consequence is a truly extraordinary decline in the fertility rate; during the period from 1950 to 2021, the global total fertility rate, the average number of children a woman would have over her lifetime if she were to experience the current age-specific fertility rates throughout her reproductive years, more than halved, from 4.8 to 2.2.15 More than half of all countries on earth now have a fertility rate below 2.1, usually considered the replacement-level fertility rate. This means that their populations are not growing naturally and may begin to decline without immigration. Within a generation, we have gone from a planet that worries about overpopulation to one that worries about depopulation.
Sub-Saharan Africa is the exception; although it has also seen declines in fertility rates, 44 out of its 46 countries still measure above-replacement rates. In 2021, almost 30% of all global live births were in sub-Saharan Africa. One important reason for this slower decline in fertility rates in Africa is because the continent did not experience a Green Revolution similar to Asia or the Americas.
There are several reasons why it did not, but I will focus on what I consider to be the most important: politics. South Africa is a case in point. For much of the twentieth century, the South African government supported white farmers financially; this ended after the demise of apartheid. Agricultural economist Jan Greyling and co-authors use agricultural censuses from 1918 to 2015 to show that government support shifted maize production to areas with lower and more unpredictable rainfall.16 This crop movement was incentivised by government subsidies that stabilised the price of maize. Physically, this movement was made possible by the development of HYVs, improved production practices and investments in grain handling infrastructure. Paradoxically, while HYVs boosted agricultural productivity in Asia and the Americas, these same technologies solidified political support for the apartheid government in South Africa and hurt economic growth. This policy had a triple negative effect: it increased the price consumers paid for a staple food item, forced the government to export surpluses at a loss, and exposed the maize crop to greater climate risk.
Politics still prevent the spread of HYVs in many African countries today. Genetically modified crops, in particular, hold immense promise to eradicate food insecurity, yet the public perception remains that it is unsafe, despite scientific evidence to the contrary. As one overview study summarised: African governments ‘should take full control of food security decisions in Africa and be driven by science-based outcomes rather than foreign proponents, politics and unsubstantiated misinformation that could cause public distrust.’17 A future Africa where farmers have access to HYVs will not only improve food security but also reduce infant mortality and stabilise population growth.
There are two reasons for optimism about food security in Africa. Globalisation now allows countries to exploit their comparative advantage. For instance, Kenya has become a leading exporter of flowers, capitalising on its favourable climate and access to international markets. Côte d'Ivoire has leveraged its ideal conditions for cocoa production to become one of the world’s largest exporters of cocoa beans. In the next chapter, we’ll see how globalisation has facilitated this specialisation, and the challenges that still remain.
A second reason for optimism is technological innovation. From information and communication technologies, as we’ll see in Chapter 33, to biotech advances that speed the development of new genetically modified crops to remote sensing systems that allow for precision agriculture, millennia-old practices are now being discarded for machines and methods that improve productivity and sustainability. Take those cocoa farmers in Côte d'Ivoire. Using tools such as low-cost sensors, machine learning models and satellite remote sensing from the NASA’s GRACE mission and ERA5 Copernicus climate change service, small-scale farmers can now monitor the health of their crops by taking images on their mobile phones and optimise water management by analysing satellite data.18 Not only do these technologies help improve soil quality, plant health and yield, but they also facilitate better access to weather predictions, market information and financial products.19 African farmers can today produce much larger surpluses than they could only a decade or two ago.
What is remarkable is that it is now space technologies that make much of this increased efficiency possible. SpaceX, founded by the South African-born Elon Musk, has substantially reduced the cost of launching satellites into orbit by designing and building reusable rockets. It began launching its own Starlink satellites in 2019 and, as of early March 2024, has over 6,000 mass-produced small satellites in low Earth orbit, providing internet coverage in more than 100 countries and often serving rural customers – farmers.
‘For every human being who looks up at the moon in the nights to come will know that there is some corner of another world that is forever mankind’, Nixon’s speechwriter wrote in 1969. He could not have guessed that humanity’s prosperity today – and our ability to sustain a planet with almost 10 billion people this century – is entirely dependent on those who set out to conquer space.
https://www.discovermagazine.com/the-sciences/if-the-apollo-11-astronauts-died-heres-the-speech-nixon-would-have-read↩︎
Ehrlich, Paul R. (1968). The Population Bomb. Ballantine Books.↩︎
Ibid., p. 131.↩︎
UN, World Population Prospects (2022)↩︎
Singh, S. 2011. Norman Borlaug: A Billion Lives Saved. AgBioWorld. Available online: https://www.agbioworld.org/biotech-info/topics/borlaug/special.html↩︎
Gollin, D., Hansen, C. W., & Wingender, A. M. (2021). Two blades of grass: The impact of the green revolution. Journal of Political Economy, 129(8), 2344-2384.↩︎
Ibid. p. 2378.↩︎
Cushman, G. T. (2013). Guano and the opening of the Pacific world: a global ecological history. Cambridge University Press.↩︎
Santana-Sagredo, F., Schulting, R. J., Méndez-Quiros, P., Vidal-Elgueta, A., Uribe, M., Loyola, R., ... & Lee-Thorp, J. (2021). ‘White gold’ guano fertilizer drove agricultural intensification in the Atacama Desert from AD 1000. Nature Plants, 7(2), 152-158.↩︎
Mathew, W. M. (1970). Peru and the British guano market, 1840-1870. The Economic History Review, 23(1), 112-128, quote on page 112.↩︎
Snyders, H. (2021). “Little More than Rich Soil?”: The Anatomy and Politics of the Cape Bat Guano Trade, 1890–1920. African Historical Review, 52(1), 72-98; Snyders, H. (2020). “Preventing a silent wilderness, securing the economic bounty”–Cape guano and the politics of seabird protection during the 19th and early 20th century. New Contree, 85, 22.↩︎
Smil, V. (2004). Enriching the earth: Fritz Haber, Carl Bosch, and the transformation of world food production. MIT press.↩︎
Vollset, S. E., Goren, E., Yuan, C. W., Cao, J., Smith, A. E., Hsiao, T., ... & Murray, C. J. (2020). Fertility, mortality, migration, and population scenarios for 195 countries and territories from 2017 to 2100: a forecasting analysis for the Global Burden of Disease Study. The Lancet, 396(10258), 1285-1306.↩︎
Gollin, D., Hansen, C. W., & Wingender, A. M. (2021). Two blades of grass: The impact of the green revolution. Journal of Political Economy, 129(8), 2344-2384.↩︎
Bhattacharjee, N. V., Schumacher, A. E., Aali, A., Abate, Y. H., Abbasgholizadeh, R., Abbasian, M., ... & Bahri, R. A. (2024). Global fertility in 204 countries and territories, 1950–2021, with forecasts to 2100: a comprehensive demographic analysis for the Global Burden of Disease Study 2021. The Lancet, 403(10440), 2057-2099.↩︎
Greyling, J.C., Pardey, P.G. & Senay, S. (forthcoming). Agricultural Policy and Crop Location: Long-run Output and Spatial Climate Risk Consequences. American Journal of Agricultural Economics.↩︎
Gbadegesin, L. A., Ayeni, E. A., Tettey, C. K., Uyanga, V. A., Aluko, O. O., Ahiakpa, J. K., ... & Odufuwa, P. (2022). GMOs in Africa: status, adoption and public acceptance. Food Control, 141, 109193, quote on page 13.↩︎
Ferraris, S., Meo, R., Pinardi, S., Salis, M., & Sartor, G. (2023). Machine learning as a strategic tool for helping cocoa farmers in Côte D’Ivoire. Sensors, 23(17), 7632.↩︎
Benami, E., Jin, Z., Carter, M. R., Ghosh, A., Hijmans, R. J., Hobbs, A., ... & Lobell, D. B. (2021). Uniting remote sensing, crop modelling and economics for agricultural risk management. Nature Reviews Earth & Environment, 2(2), 140-159; Benami, E., & Carter, M. R. (2021). Can digital technologies reshape rural microfinance? Implications for savings, credit, & insurance. Applied Economic Perspectives and Policy, 43(4), 1196-1220.↩︎