US: The population bomb is still ticking
Ehrlich is Bing Professor of Population Studies and President of the Center for Conservation Biology at Stanford University. He received his PhD from the University of Kansas. As co-founder with Peter H Raven of the field of co-evolution, Ehrlich has pursued long-term studies of the structure, dynamics and genetics of natural butterfly populations.
He has also been a pioneer in alerting the public to the problems of overpopulation and in raising issues of population, resources and the environment as matters of public policy. A central focus of his group is investigating ways that human-disturbed landscapes can be made more hospitable to biodiversity.
The Ehrlich group's policy research on the population-resource-environment crisis takes a broad overview of the world situation but also works intensively in such areas of immediate legislative interests as endangered species and the preservation of genetic resources. A special interest of Ehrlich's is cultural evolution, especially with respect to environmental ethics.
UWN: Your dire predictions in The Population Bomb did not occur, in great part due to the green-revolution dramatic increase in crop productivity. With the human population likely to soon surpass 7 billion and eventually top 9 billion mid-century, what is your current prediction?
Ehrlich: Actually many of the dire predictions were accurate - on pandemics, climate change, and even on hunger. After the recent death of Norman Borlaug, the 'father of the Green Revolution', the Wall Street Journal published a column by an anti-environmental pundit, Gregg Easterbrook, titled The Man Who Defused the Population Bomb. Easterbrook was echoed by many right-wing commentators in the blogosphere, pointing out (accurately) that I had predicted shortly before Borlaug was awarded his Nobel Prize that "the battle to feed all of humanity is over". But they claimed (ridiculously) directly or by inference that population was not a problem.
What they neglected to point out was that conservatively 5-10 million people, mostly children, have died of starvation or hunger-related disease every year since Borlaug got the prize - which cumulatively amounts to roughly the present population of the United States.
Borlaug himself stated that his work only bought a little time to solve the population problem. Little has been done so it is no surprise that since The Population Bomb was written we have not even come close to feeding all of humanity and today a record number of people, more than a billion, are starving.
But in the 1960s, in line with the views of the agriculturalists I consulted, I did badly under-rate the speed with which farmers in developing nations would adopt the high-yielding, water and fertiliser-sensitive strains of grains Borlaug and his colleagues were developing.
The success of those 'green revolution' crops in averting even greater famines than were occurring at the time is legendary and Borlaug richly deserved the Nobel Prize he earned in 1970 for his efforts.
Producing food is the single most important human activity today. Now at least 20% of Earth's ice-free land surface is covered by crops and more than another 25% is devoted to grazing domestic animals. The agricultural enterprise is a major driver of global change and is also intimately connected with the decline of the three crucial kinds of natural capital on which food production depends: fertile agricultural soils, 'fossil' ground water and biodiversity.
As the 21st century unfolds, that enterprise is in an especially precarious position. The multiple demands being placed on it will be very difficult to meet without substantial luck with the changing climate and without massive new investments in basic and applied research. The latter needs to be in areas such as plant genetics and ecology to provide the basic knowledge and practical results needed to follow Borlaug's example and increase harvests while minimising impacts on an increasingly fragile environment.
Climate disruption is likely to alter not only temperatures but also the temporal and spatial distribution of rain and snowfall, all of which are critical for growing crops. Besides the need for appropriate temperatures for crop growth, water must be supplied in approximately the right amounts and at the right time. While most agricultural areas are rain-fed, the roughly 18% of agricultural land that is irrigated (often by groundwater) supplies some 40% of the world's food.
Almost all the world's land that is suitable for agriculture, including what can be reasonably irrigated, is already being cultivated, and what still could be converted to cropland is generally of inferior quality. In recent decades, a significant portion in the order of 10% or more ¬of the world's agricultural land has become too degraded to produce economically viable yields, and has been taken out of production.
In many cases, the cause has been poorly managed irrigation; in others, soil erosion and loss of fertility. In cases of serious degradation, restoration would not be possible at a reasonable cost. All this places huge pressure on plant geneticists to develop crop strains that can increase production on land already under cultivation, and that can thrive under more extreme climatic conditions.
Because farming is so spatially extensive, transport is a key part of any modern agricultural system. Food must be transported to markets, and inputs (seeds, fertilisers, and pesticides) must be supplied to farmers. In addition, much food undergoes processing and packaging before it reaches supermarkets, all of which involves further transport of food and materials and expenditure of fossil fuels.
An important component of industrial agriculture thus is energy, which is needed for operating agricultural machinery and powering the necessary transportation, processing, and cold storage facilities. Furthermore, fossil fuels are essential for producing fertilisers and pesticides. As ecologist Howard Odum put it long ago, we eat potatoes partly made from petroleum.
Today, as shortages of petroleum are predicted and it becomes increasingly clear that humanity won't be able to bear the environmental costs of burning what could be supplied, people are looking to agriculture as a potential major source of commercial energy. More and more effort is now being put into developing liquid fuels¬ - so-called biomass fuels - from grains and other plant materials by converting them by fermentation into ethanol.
As early as 2006, rapid expansion of ethanol production (due largely to its use as a gasoline additive) was raising maize prices in the United States, despite recent record and near-record harvests. Thus the need for energy has begun to compete for agricultural land with food production, although the level of competition remains to be seen.
In the US, the domestic food supply is unlikely to be seriously affected even if much of the maize crop is diverted to energy production, although prices of feed grains have already risen followed by higher meat prices. But since a large portion of the US grain crop is customarily exported, developing countries could find themselves unable to buy the grain they need to feed their populations.
For example, putting aside the oil-climate disruption connection for a moment, instability in the Middle East threatening oil supplies for the West could also threaten the food security of poor people everywhere as food prices on the world market rise with oil prices. The prospects seem to be for food prices to keep rising as the competition escalates between feeding fuel to Hummers and supplying food to increasing numbers of people.
In the past decade or two, expansion of global food production has failed to match the growing global demand. Increases in grain yields (amount produced per unit area) have lagged globally, despite the need for such increases as populations in developing countries continue to grow.
At least with present knowledge of plant genetics and physiology, in many areas limits to the potential yields of some important crops seem to be approaching. No new green-revolution-style "magic bullets" are known that could continue to expand crop harvests to meet the needs of growing populations.
In parts of southern Asia, wheat and rice are growing at close to their temperature limits in areas where water stress is likely to increase as the source of much growing-season river flows, the 'Himalayan Water Tower', is rapidly melting. But, despite the crucial need for germ plasma from wild relatives of rice to develop new strains, the conservation status of those related species is little-known and likely deteriorating rapidly.
New findings in genomics might aid in this situation but funding for institutions central to producing needed crop strains, the Consultative Group on International Agricultural Research, remains inadequate. Indeed, there are fears that in India a much-advertised 'second green revolution' today is simply a US-based effort to promote privately owned agricultural biotechnology that will negatively affect both Indian farmers and consumers.
While biotech improvements to crops have gained most of the research attention and funding in recent years, they do little to increase yields except in special situations, such as to increase salt tolerance in crops grown in arid areas. Attempts to increase pest resistance in crops by genetic engineering have already begun to encounter the evolution of ways around that resistance by the pests themselves.
To meet the growing need for food, and to compensate for deteriorating farmland in many areas, large investments are needed not only in the basic sciences that underpin agricultural productivity, but also to support Borlaug-style research explicitly directed toward increasing yields, not only of the major grains but also of a variety of neglected traditional foods. Many such foods are important regionally and provide essential subsistence for rapidly growing poor rural populations, who are most in need of expanded food supplies.
Yet the agricultural research establishment until relatively recently has largely ignored the potential for higher yields of these traditional crops and the possibility that such strains might be grown in ecologically less damaging ways.
So the short answer to the question of what's likely to happen on the food front would appear to be "lots more starving people" on the optimistic side and "billions dying and a breakdown of civilisation" (since people in South Asia have nuclear weapons) on the pessimistic side..
Q: China implemented first a two-child policy and then a one-child policy for Han Chinese and slowed their anticipated growth. India has taken a different route and has surpassed China. How do you view their strategies? What do you anticipate in terms of population growth and resultant crises these next decades?
Ehrlich: India and China are both vastly overpopulated by the simple standard that they are living on (and exhausting) their natural capital - agricultural soils, ground water, and the biodiversity that runs our life-support systems. Until and unless we can humanely begin to shrink the global population, following the lead of over-consuming and over-populated European nations, the future seems grim.
Most unfortunately, over the past few decades the principal population issues considered by activists and foundations have been of reproductive health and rights. Those, of course, are very important but they will be totally moot if overpopulation, helping to drive climate disruption, land-use change, ocean overharvesting, toxification of the entire planet, the increased probability of novel epidemics, and greater threats of resource wars - especially a nuclear one - has not abated.
The population explosion will come to an end. The only question is whether it will do so by humanity balancing its interventions to decrease death rates with interventions to decrease birth rates, or whether the death rate will soar.
Q: You and many colleagues espoused containment of urban and suburban areas, preserving the farmland and wilderness. How extensively has this containment eroded and what would you predict in the next decade?
Ehrlich: Continued erosion in the name of perpetual growth and in the face of population increase.