ting with high confidence that global crop harvests would be approximately half of current levels without nitrogen fertilizer inputs. 8 Vaclav Smil derives his calculations based on the use of nitrogen crop, livestock and human protein (of which the building blocks are nitrogen) balances. His nitrogen balance concluded that 85 percent of all nitrogen in food protein for humans is derived from cropland; the remainder came from seafood or livestock on grazing land. Since nitrogen fertilizer provided around half of the nutrient in this harvested crop, he estimated that it provided 40 percent of dietary protein in the mid-1990s. He concluded that 40 percent of the global population in 2000 were dependent on food production from synthetic fertilizers. Erisman et al. (2008) have since updated these estimates to the year 2008, estimating a similar (but slightly higher) share of 44 percent in 2000 and 48 percent in 2008. The complexities of the global food system make it challenging to provide a firm figure, however, it's likely that around half of the global population is dependent on synthetic nitrogen fertilizers. This is further shown in the chart. As a result, the Haber-Bosch process will likely have enabled the lives of around 4 billion people today. Could we have achieved the same without synthetic nitrogen? If Fritz Haber had not discovered how to make synthetic nitrogen, would we have found alternative solutions to support a population as large as today's? Addressing this question partly relies on retrospective guesswork about whether, in the absence of synthetic nitrogen fertilizer, we would have managed to supply nitrogen via other methods. If Fritz Haber or Carl Bosch (or any scientist to follow) hadn't developed a method for transforming inert atmospheric nitrogen into reactive nitrogen plants could utilize, what is the likelihood that other solutions would have filled the gap? One solution would have been to greatly increase the production of ni

almost half the people on the Earth are currently fed as a result of synthetic nitrogen fertilizer use. According to ICIS Fertilizers managing editor Julia The Green Revolution, or the Third Agricultural Revolution, was a period during which technology transfer initiatives resulted in a significant increase in crop yields. These changes in agriculture initially emerged in developed countries in the early 20th century and subsequently spread globally until the late 1980s. In the late 1960s, farmers began incorporating new technologies, including high- The Green Revolution, or the Third Agricultural Revolution, was a period during which technology transfer initiatives resulted in a significant increase in crop yields. These changes in agriculture initially emerged in developed countries in the early 20th century and subsequently spread globally until the late 1980s. In the late 1960s, farmers began incorporating new technologies, including high-yielding varieties of cereals, particularly dwarf wheat and rice, and the widespread use of chemical fertilizers (to produce their high yields, the new seeds require far more fertilizer than traditional varieties), pesticides, and controlled irrigation. At the same time, newer methods of cultivation, including mechanization, were adopted, often as a package of practices to replace traditional agricultural technology. This was often in conjunction with loans conditional on policy changes being made by the developing nations adopting them, such as privatizing fertilizer manufacture and distribution. Both the Ford Foundation and the Rockefeller Foundation were heavily involved in its initial development in Mexico. A key leader was agricultural scientist Norman Borlaug, the "Father of the Green Revolution", who received the Nobel Peace Prize in 1970. He is credited with saving over a billion people from starvation. Another important scientific figure was Yuan Longping, whose work on hybrid rice varieties is credited with saving at least as many lives. The basic approach was the development of high-yielding varieties of cereal grains, expansion of irrigation infrastructure, modernization of management techniques, distribution of hybridized seeds, synthetic fertilizers, and pesticides to farmers. As crops began to reach the maximum improvement possible through selective breeding, genetic modification technologies were developed to allow for continued efforts. Studies show that the Green Revolution contributed to widespread eradication of poverty, averted hunger for millions, raised incomes, limited the increase of greenhouse gas emissions, reduced land use for agriculture, and contributed to declines in infant mortality.