Foreclosing the future
by Grechen Daily (Nov. 1995)
Feeding a world of 8 billion could be a triumph or a disaster, argues Gretchen Daily. Casting the debate simply in terms of whether or not it could be done obscures important measures by which success should be judged.
The world in 2020 hinges upon sustaining the essential natural underpinnings of agricultural productivity because their loss would be, in many instances, completely irreversible on a time scale of relevance to humanity. Providing immediate food security for the human population when it first reaches 8 billion would constitute a Pyrrhic victory at best if done in a way that seriously undermined the goal of ensuring food security in the long run.
The global economy and, in particular, the food system, are wholly owned subsidiaries of the environment. Ignorance and denial of this fact, reflected in the tendency to subjugate environmental preservation to virtually all other perceived human needs and desires, exact a price much higher than generally appreciated. Human impacts already exceed Earth's long-term biophysical capacity to sustain present methods and levels of agricultural production.
Consider the condition of the planet's productive (vegetated) land surface, for example. In a recent study, I estimated that over 40 per cent of this land now has diminished capacity to supply benefits to humanity, due to recent direct human impacts of land use (not counting substantial indirect impacts, such as air pollution and stratospheric ozone depletion). 
This represents roughly a 10 per cent reduction in Earth's potential to yield direct benefits, such as agricultural, forestry, industrial, and medicinal products. The loss of this potential could eventually shrink to only 5 per cent if the socio-economic changes required to halt the degradation are taken swiftly, before natural recovery mechanisms are irreversibly impaired. Conversely, if present trends are allowed to continue, the loss could reach 20 per cent by the time Earth's population hits 8 billion.
Virtually every element of natural capital essential to agriculture is similarly affected. Indeed, at 5 billion people the human population was already consuming, co-opting, or destroying about 40 per cent of Earth's annual net primary productivity (NPP), the basic food supply of all terrestrial animals.
A more recent, parallel analysis of availability of water indicates that today's 5.7 billion people now use over 50 per cent of Earth's accessible renewable runoff; the remaining portion must be shared by the millions of other life forms inhabiting the planet. Increasing human dominance of the biosphere is driving other species, the very basis of our agricultural system, to extinction - up to an estimated million times faster than the rate of evolution of new species.
Humanity has exploited the richest, purest, and most accessible soils, water, minerals, and other resources first and is moving to progressively poorer and less accessible ones. Even the most optimistic rates of technological innovation would be unlikely to offset the increase in environmental deterioration associated with projected population growth and the need to exploit ever lower quality resources.
Thus, the population-food debate might be refocused on the challenge of expanding Earth's social carrying capacity -- the maximum sustainable population under a given socioeconomic system. What socio-economic changes could most effectively increase individual material wellbeing, while holding constant or reducing total human environmental impact? What alternatives exist, given the momentum of population growth and patterns of both resource consumption and deployment of technologies?
Humanity is faced with a huge array of possible paths. All sorts of policies have strong interactions with the agricultural system, directly for example, through farm subsidies, terms of trade or water pricing and indirectly through policies affecting land prices and labour markets and socio-economic equity.
Yet important obstacles strongly hinder the use of this array of levers. Paramount among them are powerful vested interests in the status quo which resists any changes that would cost them but benefit society as a whole. Thus some of the potentially most effective means of sustainably enhancing agricultural output are not pursued, such as increasing equity in opportunity - between the sexes, households, regions, and nations. For instance, gender-based inequity in access to farm credit, agricultural extension services, material inputs to farm productivity, and hired or child labour exerts a direct negative effect upon productivity. (In large parts of the world, women contribute much more farm labour than do men).
At the inter-household level, land reform that converted estates and industrial farms to large family farms would increase productivity in many circumstances. This is because, in general, family farmers operate under the incentive of maximizing production per hectare; large landowners, by contrast, profit most by maximizing production per worker. At the regional level, Lofchie aptly describes the widespread suppression of the agricultural sector in developing nations as "a policy that unites the total ensemble of urban interests."  Indeed, there is substantial evidence that increasing equity at all levels would enhance agricultural output.
At present, we are instead taking the path of least resistance, ratcheting up the pressure on natural systems, whose largest constituency - the poor, the young, and the unborn - have little influence on the policy-making process. The danger of this path is masked by the lag-times, non-linearities, and irreversibilities inherent in the response of natural systems to perturbation. Moreover, when the prospects of changing the status quo appear too daunting, one is left with a gruesome tradeoff between saving a life, even momentarily, today versus providing for many lives in the future.
Tragically, the status quo is further reinforced by the overwhelming diversity of opinion expressed in the agricultural literature, which contributes to paralysis in the policy arena. It is easy to see how this situation arose, considering the complexity of the food system. No one analyst can claim to understand all the pertinent aspects of the natural socio-economic systems in which agriculture is embedded: climate, soil, hydrology, biodiversity, epidemiology, ecology, energy, international trade, agricultural policy, social and economic policy in general, technology and culture. It is extremely difficult to formulate an integrated, holistic view of such a complex, highly interactive system.
Fortunately, absolute consensus on agricultural issues is not required, nor is it even a sensible goal. But making sound and forceful policy recommendations requires much greater interdisciplinary communication and collaboration. For example, it is absurd that so many interpretations of and forecasts based upon past trends in agricultural output ignore critical changes in the underlying basis of productivity. Economists are equally frustrated that assessments of the food situation by natural scientists so frequently ignore the influence of prices.
We are at a crossroads. Humanity now has the analytical tools and basic knowledge to discern the consequences of continuing on its present course. We are headed in the direction of increasing vulnerability to various unpleasantries, such as famine, mass migration, disease, and warfare, and at the same time rapidly foreclosing many of our best options.
The first test of whether we will apply our tools and knowledge to steer ourselves toward sustainability is whether the intellectual community, with comparatively little at stake, can pull itself together.
1. Daily, G. C. (1995), Restoring value to the world's degraded lands. Science, July 21.
2. Lofchie, M. F. (1987), The decline of African agriculture, in M.H. Glantz, ea., Drought and Hunger in Africa, Cambridge University Press.
Gretchen Daily is Bing Interdisciplinary Research Scientist at the Center for Conservation Biology, Stanford University. Dr Daily's research is at the interface of science and policy and spans topics from the ecology of birds and butterflies to socio-economic aspects of sustainability. She is the author with P. R. Ehrlich and A. H. Ehrlich of The Stork and the Plow.