During the second half of the 20th Century growth in world population threatens to outstrip food production and lead to widespread famine. The concern is crystallised by noted biologist Paul Ehrlich in his 1968 book 'The Population Bomb'.
"Americans are beginning to realise that the underdeveloped countries of the world face an inevitable population-food crisis," Ehrlich writes.
"Each year food production in these countries falls a bit further behind burgeoning population growth, and people go to bed a little bit hungrier. While there are temporary or local reversals of this trend, it now seems inevitable that it will continue to its logical conclusion: mass starvation. The rich may continue to get richer, but the more numerous poor are going to get poorer. Of these poor, a minimum of 10 million people, most of them children, will starve to death during each year of the 1970s. But this is a mere handful compared to the numbers that will be starving before the end of the century. And it is now too late to take action to save many of those people."
Born on 25 March 1914 in Saude, near Cresco, Iowa, US. Borlaug is the son of Norwegian immigrant farmers. He is the eldest of four children and works on the family farm until he is 19.
1933 - After graduating from Cresco High School, Borlaug enlists in the National Youth Administration, one of the 'New Deal' agencies set up by the Roosevelt administration to address the fallout from the Great Depression.
He later wins a place at the University of Minnesota. He studies forestry science and works periodically for US Forestry Service to help pay for his education.
1937 - Borlaug completes his degree in forestry. When a full-time job in the Forestry Service falls through he enrols in a graduate program headed by plant pathologist Elvin Charles Stakman. He obtains a masters degree in 1940 and a PhD in plant pathology and genetics in 1942.
From 1942 to 1944 Borlaug works as a microbiologist at DuPont chemicals company, developing industrial and agricultural bactericides, fungicides and preservatives.
Meanwhile, he marries Margaret Gibson. The couple will have a daughter, Jeanie, and a son, William. A second son, Scotty, is born with spina bifida and dies in childhood.
1944 - Borlaug joins the Cooperative Wheat Research and Production Program, a project between the Mexican Government and the Rockefeller Foundation. Mexico's wheat harvest has been halved by stem rust, forcing and the country to import more than half of its grain. The program seeks to reverse this decline. It is directed by Borlaug's mentor, Elvin Stakman, along with J. George Harrar, also a plant pathologist.
Borlaug is at first disheartened by what he finds in Mexico. "These places I've seen have clubbed my mind - they are so poor and depressing," he writes his wife. "I don't know what we can do to help these people, but we've got to do something."
Over the next 10 years Borlaug selects and cross-pollinates wheat from around the world to develop high-yielding, robust and disease-resistant hybrid strains suitable for cropping in a variety of climates. The new strains when combined with intensive crop management practices allow three or four times as much wheat to be grown on the same amount of land.
High-yielding strains of rice and maize are later developed using similar techniques.
By 1956 Mexico is self-sufficient in wheat. By 1963 its wheat harvest is six times larger than in 1944.
However, the high yields are dependent on the liberal use of chemical fertilisers and pesticides, requirements that are later called into question by environmentalists and lead to a reevaluation of Borlaug's legacy.
1960 - The Rockefeller Foundation backs the creation of a centre devoted to the development of high-yield rice, the International Rice Research Institute, near Manilla in the Philippines. The first strain is released by the Institute in 1966. It doubles the yield from rice fields.
Meanwhile, Borlaug takes his techniques to India and Pakistan. The Green Revolution in the subcontinent nearly doubles food production between 1965 and 1970. Pakistan is a self-sufficient wheat producer by 1968. India reaches self-sufficiency a few years later. By 1974 India is self-sufficient in all cereals. Food production in both countries outpaces population growth.
The Green Revolution spreads across the globe, with China becoming one of its spectacular success stories.
Between 1950 and 1992 world grain production increases 2.8 times, while world population increases only 2.2 times and the area of land cropped rises only one percent.
It is estimated that the Green Revolution saves the lives of up to one billion people who may have otherwise starved.
"Without high-yield agriculture," Borlaug says, "either millions would have starved or increases in food output would have been realised through drastic expansion of acres under cultivation - losses of pristine land a hundred times greater than all losses to urban and suburban expansion."
1966 - The Mexican Government and the Rockefeller Foundation establish the International Maize and Wheat Improvement Centre (CIMMYT) in Mexico City, an offshoot of the Cooperative Wheat Research and Production Program.
Borlaug is appointed director of the centre's wheat improvement program. He trains more than 2,000 scientists from 20 countries.
1968 - The US Agency for International Development calls the new agricultural techniques a "Green Revolution". Use of the term takes off from there.
1970 - Borlaug wins the Nobel Peace Prize.
"More than any other single person of this age, he has helped provide bread for a hungry world," Mrs Aase Lionaes, Chairman of the Nobel Committee, says. "We have made this choice in the hope that providing bread will also give the world peace."
"It has been established beyond doubt that (Dr Borlaug's) efforts have made possible an unequalled increase in wheat production and an improvement in quality that have postponed a crisis that a great many scientists have predicted would be the result of the growing gap between the population explosion and food production."
Borlaug acknowledges that the breakthroughs of the Green Revolution were not due to his efforts alone.
"When the Nobel Peace Prize Committee designated me the recipient of the 1970 award for my contribution to the 'Green Revolution', they were in effect, I believe, selecting an individual to symbolise the vital role of agriculture and food production in a world that is hungry, both for bread and for peace," he says in his Nobel lecture.
"I am but one member of a vast team made up of many organisations, officials, thousands of scientists, and millions of farmers - mostly small and humble - who for many years have been fighting a quiet, oftentimes losing war on the food production front."
Borlaug also warns of the "magnitude and menace of the "Population Monster'."
"The Green Revolution has won a temporary success in man's war against hunger and deprivation; it has given man a breathing space," he says. "If fully implemented, the revolution can provide sufficient food for sustenance during the next three decades. But the frightening power of human reproduction must also be curbed; otherwise the success of the green revolution will be ephemeral only."
1977 - He is awarded the Presidential Medal of Freedom.
1979 - Borlaug officially retires as director of the wheat improvement program at CIMMYT, though he continues to serve as a senior consultant to the centre.
1984 - He is appointed as Distinguished Professor of International Agriculture in the Department of Soil and Crop Science at Texas A&M University.
1986 - Borlaug attempts to bring his techniques to sub-Saharan Africa. He is appointed president of the Sasakawa Africa Association, a private Japanese foundation working to achieve food security for the region. However, due to on-ground political and social instability, lack of infrastructure and lobbying by Western environmentalists, the program is only partially successful.
"World Bank fear of green political pressure in Washington became the single biggest obstacle to feeding Africa," Borlaug says.
"Some of the environmental lobbyists of the Western nations are the salt of the earth, but many of them are elitists. They've never experienced the physical sensation of hunger. They do their lobbying from comfortable office suites in Washington or Brussels. If they lived just one month amid the misery of the developing world, as I have for 50 years, they'd be crying out for tractors and fertiliser and irrigation canals and be outraged that fashionable elitists back home were trying to deny them these things."
Meanwhile, Borlaug establishes the World Food Prize, an annual award to recognise "achievements of individuals who have advanced human development by improving the quality, quantity or availability of food in the world."
2000 - Borlaug returns to the Nobel Institute in Oslo to present a lecture marking the 30th anniversary of his Nobel Peace Prize.
"Despite the successes of the Green Revolution, the battle to ensure food security for hundreds of millions of miserably poor people is far from won," he warns.
"For the genetic improvement of food crops to continue at a pace sufficient to meet the needs of the 8.3 billion people projected in 2025, both conventional breeding and biotechnology methodologies will be needed. ...
"While the affluent nations can certainly afford to adopt ultra low-risk positions, and pay more for food produced by the so-called 'organic' methods, the one billion chronically undernourished people of the low income, food-deficit nations cannot. ...
"As Kenyan archaeologist Richard Leakey likes to reminds us, 'you have to be well-fed to be a conservationist!' We need to bring common sense into the debate on agricultural science and technology and the sooner the better!"
Borlaug also advocates the use of genetically modified crops. "You can philosophise about this but I've been in the field for a long time and I believe genetically modified food crops will stop world hunger," he says in 2002.
"I recognise the value of crops created by traditional plant breeding but I also see the viability of crops that carry an herbicide-resistant gene or whatever gene is incorporated by biotechnology."
2006 - The Rockefeller Foundation and the Bill and Melinda Gates Foundation establish the Alliance for a Green Revolution in Africa. The alliance aims to work with governments in Africa to increase food security and reduce poverty.
2007 - Borlaug's wife, Margaret, dies on 8 March.
On 17 July Borlaug is presented the Congressional Gold Medal, the highest civilian honour of the US. The citation for the award reads, "Mr Borlaug has saved more lives than any other person who has ever lived."
Speaking at the presentation, Borlaug returns to the debate about the environmental impacts of intensive farming. "Critics of modern agricultural technology invariably turn a blind eye on what the world would have been like without the technological advances that have occurred, largely during the past 50 years," he says.
"For those whose main concern is protecting the 'environment,' let's look at the positive impact that the application of science-based technology has had on land use. If the global cereal yields of 1950 still prevailed in 2000 we would have needed nearly 1.2 billion ha of additional land of the same quality - instead of the 660 million ha that was used - to achieve the global harvest of that year. Obviously, such a surplus of land was not available, and certainly not in populous Asia, where the population had increased from 1.2 to 3.8 billion over this period. Moreover, if more environmentally fragile land had been brought into agricultural production, the impact on soil erosion, loss of forests and grasslands, biodiversity and extinction of wildlife species would have been enormous and disastrous."
2009 - Borlaug dies of lymphoma at his home in Dallas, Texas, on 12 September.
The dire prediction by Paul Ehrlich in 1968 that "a minimum of 10 million people, most of them children, will starve to death during each year of the 1970s" never came to pass. For this we have to thank the high-yield crops and intensive farming techniques developed by Norman Borlaug and his colleagues.
But while Green Revolution techniques are now standard agricultural practice throughout most of world, they are not without their critics.
It has been said that the Green Revolution has succeeded at the cost of the environment and local communities and may not be sustainable in the long term.
Chemicals used to grow high-yield crops are said to have polluted water supplies and endangered the health of farm workers. Intensive farming techniques are said to have lead to land degradation from salinity, erosion and the impoverishment of soil structure. The cropping of high-yield varieties is said to have reduced agricultural biodiversity. The replacement of small family farms by large agricultural enterprises is said to have lead to the dislocation of traditional communities and an over-reliance on corporate providers.
Supplies of fertilising agents like potassium, phosphorus and magnesium are finite and the production of chemical fertilisers and pesticides requires considerable energy input. Critics ask what will happen when the resources run out or the cost of energy goes up?
Borlaug had responses to many of these criticisms.
"If we had continued practicing conventional farming," he said in 2002, "we would have cut down millions of acres of forest, thereby destroying wildlife habitat, in order to increase cropland to produce enough food for an escalating population. And we would have to use more herbicides in more fields, which would damage the environment even more. Technology allows us to have less impact on soil erosion, biodiversity, wildlife, forests, and grasslands."
- The Nobel Prize in Peace 1970 - Norman Borlaug
- Biotechnology and the Green Revolution - ActionBioscience
- Billions Served: Norman Borlaug interviewed by Ronald Bailey
- Forgotten Benefactor of Humanity
- Norman Borlaug: The Legend
- The World Food Prize - Improving the Quality, Quantity and Availability of Food in the World - Norman E. Borlaug - Extended Biography