FEEDING THE TEN BILLION
PLANTS AND POPULATION GROWTH
L.T. EVANS
CAMBRIDGE UNIVERSITY PRESS 1998
PART 1
Back cover
At the current rate of increase, the world’s population is likely to reach ten billion by the middle of the 21st century. What will be the challenges posed by feeding this population and how can they be addressed? Written to mark the 200th anniversary of the publication of Malthus’ seminal ‘Essay on the Principles of Population’, this fascinating book looks at the intimate links between population growth and agricultural innovation over the past 10,000 years, providing a series of vignettes which illustrate how the evolution of agriculture has both shaped and been shaped by the course of world population growth. This historical context serves to illuminate our present position and to aid understanding of possible future paths to food security for the planet.
Preface by Lloyd Evans
- Since long before the publication in 1798 of Robert Malthus’ Essay on the Principle of Population there has been anxiety that our numbers might soon outstrip our food supply.
- After two billion arrived, Aldous Huxley, William Vogt and others were pessimistic: we had to tighten our Malthusian belts.
- In 1951 Le Gros Clark and Pirie asked ‘How shall we work the miracle of feeding the four billions?’ Yet those billions had accumulated by 1975, better fed than ever in spite of the Paddock brothers’ prediction of Famine-1975!
- More recently, Lester Brown has issued his annual jeremiads in the World Watch Institute’s State of the World reports as the world population continues to grow.
- There have also been optimists, of course, some of whom have estimated that the world could feed more than 50 billion people.
- Between these vocal extremes there have been well-informed agriculturists, such as Sir John Russell in 1954 and Daniel Hillel in 1991, who have expressed ‘tempered’ or ‘conditional’ optimism about the future of the world’s food supply.
- The enormous success of the ‘Green Revolution’ in the 1960s and 1970s may have lulled governments of both more and less developed countries into believing that further revolutions can be summoned up as required, especially with the aid of biotechnology.
- It is easy to see why both laypeople and governments are confused about the capacity of the earth to feed us.
- In this book I try to link the multiplication of our species with some of the advances in the domestication, adaptation, improvement and management of our food crops. The focus is on plants, not animals, and on those crops which either directly or indirectly provide us with most of our food.
- By linking population growth with successive advances in agriculture we come to recognize that not only has agricultural evolution made increase in population possible – indeed it has been blamed for it – but also that population growth has driven the development of agriculture.
- We see some of the great variety of innovations along the way, and of the crucial but often unexpected synergisms between them.
- We also come to recognize that the path to feeding the ten billion in a sustainable way is still by no means clear.
Chapter 1: Introduction: Timebomb or Treadmill?
- Since the 1960s the advances made in the yields of the staple food crops and the accumulation of surplus agricultural capacity in several developed countries have led many to conclude that the world’s food supply problems have, in principle, been solved.
- As the real world prices for the staple cereals continue to fall, agricultural science seems to have succeeded too well.
- Given that a world population of at least ten billion is almost inevitable by the latter half of the 21st century, what are our chances of nearly doubling the world’s food supply over the next 50 years or so, and at what cost in terms of long-term sustainability?
- Some experienced agriculturists think it will be relatively easy, others are pessimistic, but virtually all would be concerned by the likely environmental costs.
- ‘How much land can ten billion people spare for Nature?’ is a question recently considered by Paul Waggoner. The quotation from the Essay given above makes it clear that he regarded the supply of food as the driving variable and population as the dependent one.
- Ester Boserup says ‘that the main line of causation is in the opposite direction: population growth is here regarded as the independent variable which in turn is a major factor in determining agricultural developments.’
- Increasingly, human imagination and understanding, based on research and by no means always driven by population pressure, have become a major accelerator of agricultural progress and, to a much smaller extent, decelerator of population growth.
- Along with this change in recent years, there has been growing apprehension about the long term health of the agricultural and environmental systems of the world as a whole, evident in the current emphasis on ‘sustainability’.
- Effective husbandry of their resources has long been a major concern of good farmers, but likewise at all stages in the evolution of agriculture farmers have had to balance opportunities and innovations with their costs and risks, often not fully recognized at the time.
- From the hazards to health in Neolithic villages, through those of salination in Mesopotamia and of soil loss from the Aegean hills, to the environmental consequences of applications of DDT, fertilizer and herbicide, agriculturists have had to weigh the benefits and costs, both social and environmental, both short and long term, of each innovation.
- Another theme which I hope emerges in this book is the continually evolving approach to the age-old and still recurrent problems for agriculture posed by pests, diseases, weeds, fertility maintenance, power supply, crop improvement, etc.
- Whatever the myths, there has never been a golden age in agriculture when moth and rust did not corrupt, nor will there be a permanent solution to these problems.
- Throughout most of this book I shall refer to the evolution, not revolution, of agriculture.
- At times when several innovations, agrarian as well as agricultural, have interacted synergistically, as they did in Norfolk in the 18th century, the pace of change has accelerated and a revolution can be diagnosed, but even then its geographic spread may be slow and uneven.
- My aim in this book is not a history of agriculture. Rather, I shall explore the inter-relations between growth of the world population and the evolution of agriculture over the last 10,000 years to illustrate the variety of ways in which agricultural change has occurred and of the stimuli which led to these changes.
- By doing so I hope to aid public understanding of the challenges facing agriculture in the third century after Malthus.
- Our aim in this book is to understand how the evolution of agriculture has both shaped and been shaped by the course of world population growth.
Chapter 2: Reaching Five Million (To 8000 BC)
2.1 Introduction: The silent millennia
- Humankind has depended for its subsistence on hunting and gathering for more than 99% of its evolutionary history, yet since that time its population has increased 1000-fold.
- Given the many uncertainties about human behaviour 10,000 years ago, we should not be surprised to find strongly opposed views about population pressure and its role in bringing our total dependence on hunting and gathering to an end.
- The first primates appeared about 60 million years ago, 5 million years after the demise of the dinosaurs and at about the same time as the wheat, rice and maize genomes began diverging.
- The use of fire associated as far back as 1.4 million years ago in Africa, and became relatively common 200,000 to 300,000 years ago when there was an apparent increase in meat eating.
- In the following years stone and blade tools became predominant, bows and arrows were invented, fire was used not only for cooking but also to manipulate vegetation and facilitate hunting.
- Our views of the hunting and gathering lifestyle have veered wildly throughout history. Several of the 19th century Australian explorers were greatly impressed by the food and water-finding skills of the aborigines and by their ability to sustain themselves even under adverse conditions.
- Today’s hunter-gatherers have only the poorest, most difficult environments in which to survive, ie those not already claimed for agriculture, grazing or forestry.
- One characteristic common to all hunter-gatherers is their great knowledge of plants and their life cycles and of animal behaviour. Their survival depended on it.
- There is accumulating archeological evidence that the hunting/gathering lifestyle was sometimes combined with an element of agriculture, at least in more favorable areas.
2.2 Australian aborigines
2.3 The !Jung San of Dobe
2.4 Tell Abu Hureyra
Chapter 3: Towards fifty Million (8000 BC – 2000 BC)