The three studies reviewed herein cover the middle range between optimism and pessimism about our ability to meet the dietary needs of an expanding world population, as estimated to approach 7.7 billion by 2020 and 9.1 billion in 2050. None believe that adequate diets (variously defined) are possible for a global population of 9 billion given each study's assumptions about resources and yields. The issue at the heart of the question is whether population growth will outpace increases in food production, given technological advance and dissemination, less any productivity decrease due to limits on natural resource availability and crop land degradation. An increase in food demand by 2050 will come not only from population increase, but also from the need to raise per capita food consumption among the least developed countries to a level of adequate nutrition. Additionally, if economic development does not sufficiently increase incomes and purchasing power in the developing world, their inability to import adequate food supplies will negate the utility of the concept of "global average" food supply in evaluating our ability to feed 9 billion people.
Gilland (2002) is decidedly optimistic that efficiency gains and further
increases in input intensity will allow agricultural production gains to
provide a population of 8 billion with an adequate food. He defines 8 billion
as the carrying capacity of the planet given his assumptions about agricultural
production trends until 2050 (61). Looking at a shorter time horizon, Rosegrant
and Sombilla (1997) conclude that policies regarding natural resource use
and trade will determine whether natural resource constraints limit food
production to a level below that needed to adequately feed the global population
in 2020. Brown and Kane (1994) are the least optimistic that natural resource
constraints will not fundamentally hinder our ability to feed a population
of 9 billion. Concerned with issues of sustainability and the vulnerability
of the food supply, these authors predict that declining growth in food
output will limit available supply as well as increase the price of food
staples, further frustrating the ability of poor nations to obtain the necessary
nourishment for their growing and youthful populations (47-8).
In declaring his disagreement with both technological optimism and ecological
pessimism (61), Gilland argues that increasing the use of high-yield crop
varieties, the application of chemical fertilizers and irrigation of cropland
will allow us to produce food supplies adequate to provide a "satisfactory
average diet" (47) only if it is coupled with a substantial decrease
in the population of the least developed countries from their future peak
(47). Gilland's main premise, taking after Norman Bourlag, is that the Green
Revolution and future gains in production yields are limited and thus, must
be accompanied by curbing "the frightening power of human reproduction"
(48). Gilland defines an adequate diet as that containing at least 40g of
animal protein per day, a figure substantially higher than that currently
consumed by the majority of the world's population, with 72% consuming fewer
than 30g/day in 1999 (51). Interestingly, Gilland notes the importance of
maintaining a world food supply in excess of global physiological caloric
needs, as inequity, spoilage, waste and non-human domestic consumption must
be allowed for (50). Despite the need to increase food production more rapidly
than the pace of growth in population, due to the need to lift millions
of people out of a state of malnourishment and to the projected increase
in consumption of resource intensive animal products, Gilland remains optimistic
about the capacity of global agriculture. He dismisses ecological arguments
of declining natural capacity, assuming that per capita global average production
will remain around 360kg (54). A continued and even substantially increasing
reliance on chemical fertilizers (especially nitrogen) to boost cereal crop
yields is advocated and the ecological costs as well as diminishing returns
to fertilizer use are largely rejected by Gilland in favor of optimism about
future increases in nutrient uptake efficiency (55-6). Additionally, Gilland
places substantial faith in continued advances in biotechnology and no emphasis
on the likely continued inability of developing country farmers to procure
the fertilizer inputs and bioengineered seeds necessary to increase yields.
Given the need to increase irrigation in order to boost yields in the developing
world, water availability and distribution are important potential ecological
constraints that are explored by Gilland. Citing increased water competition
from urban usage and rising costs of irrigation, Gilland finds that water
supply may become a limiting factor for agricultural productivity (57).
However, Gilland remains optimistic that use efficiency will negate scarcity
constraints. Gilland also briefly discusses the reality of massive discrepancy
in average consumption between the more and less developed countries; the
LDCs are already reliant on significant quantities of food imports, a reality
that will become increasingly dire as population growth disproportionately
affects these nations. Gilland finds that the LDCs will require three times
the quantity of food imports from the MDCs in 2050 as in 1999 (59). While
he notes the importance of such transfers in moving towards meeting the
dietary needs of LDC populations, Gilland ignores the current and (potentially
exacerbated) future inability of the LDCs to develop sufficiently in order
to have the incomes required to obtain MDC food surpluses through trade,
a point emphasized by Brown and Kane. Brushing off the potentially serious
effects of a declining ecological capacity to sustain intensive food production
and the inability of the poor to obtain food imports, Gilland concludes
that we have the ability to increase global grain production by 60% by 2050
(60). However, such production gains still would not provide adequate nutrition
for more than 8 billion, Gilland says, making his answer to the question
at issue a "no" for 2050.
Noting the centrality of environmental and natural resource factors in determining
agricultural yields, but still espousing a substantial air of productive
capacity optimism, Rosegrant and Sombilla (1997) argue that resource degradation
and scarcity will "seriously hamper" (1467) food security only
if policies do not change quickly to promote efficient and wise use of resources.
Rosegrant and Sombilla find that a combination of slower population growth
and declining income elasticities of cereal demand will allow global real
cereal prices to continue to decline (1467), which will increase the ability
of poorer consumers to obtain food. However, they also note that despite
falling population growth rates, 82% of the projected 40% increase in global
grain demand and 90% of the increase in meat demand, will occur in the developing
world (1467). The authors propose that such an increase in demand may be
met by a combination of increased agricultural productivity, improved animal
yields and expansion of the global food trade (1468). However, Rosegrant
and Sombilla also find a continued decline in the rate of global agricultural
yield growth from 1.5% per year to 1.1% per year for their projection period
from 1993-2020. The central factors potentially limiting future agricultural
yield growth are the adverse environmental effects of fertilizer use, energy
resource availability, land degradation, water scarcity and climate change.
While each may threaten productivity, especially if policies are not re-designed
to increase input efficiency and reduce environmental harm, the authors
are optimistic that projected yields in 2020 are not only attainable, but
will remain far from their peak potential (1469). Of the potential limiting
factors, Rosegrant and Sombilla find water scarcity, driven by increasing
resource utilization for urban industrial uses as well as the rising cost
of development of increasingly marginal water sources, to be the most pressing
of potential constraints (1469). The problem, they find, will be particularly
acute in the developing world, where it could pose a "serious threat
to future growth in food production" (1469) if policy reforms are not
soon undertaken to encourage efficiency and conservations through such mechanisms
as tradable water rights or alteration of subsidy schemes (1470). Rosegrant
and Sombilla do not adequately stress the added complication that water
privatization schemes will disproportionately affect the costs of water
use to agricultural users as opposed to more wealthy and powerful urban
and industrial interests. This will further exacerbate any water shortages
that threaten productivity and the food supply. While not providing a definitive
answer to whether we will be able to feed a population of 9 billion, Rosegrant
and Sombilla seem optimistic that ecology is only a serious constraint if
we do not properly manage and optimize our use of those vital resources.
The authors conclude that biotechnology research, global health and education
investments, coupled with global trade and market development and rapid
income growth (to raise the ability of the poor to access the food market),
will be the critical factors behind whether or not we can provide the nutritional
resources necessary to feed a growing population.
Brown and Kane (1994) provide a decidedly less optimistic picture of our
ability to sustainably keep agricultural production increasing at the levels
needed to meet new population demands. In addition to the aforementioned
declining gains in yields and the lack of dissemination of advances to needy
farmers (38), the authors cite grain source concentration, resource exhaustion
and production distortion due to subsidies as drivers of food supply instability
today and into the future. Concentration of dependence upon North American
crop production, they argue, exposes the global population to lower food
security as a single climatic event could decimate a large proportion of
world supply (42). Of the three studies, Brown and Kane are the only authors
to deem current land and water use practices "unsustainable" (43).
While such practices have provided the basis for substantial gains in production
in the past, Brown and Kane question the longevity of such high yields as
vital natural resources are consumed and degraded (43). The authors find
that an extrapolation of current US agricultural sustainability estimates
"undoubtedly show sustainable world food output running well below
consumption" (43), even at the population level in 1994. Finally, Brown
and Kane charge that agricultural policy has tended to exacerbate both poor
resource management and the inadequacy of the global food trade (44). Additionally,
they point to development and economic indicators that further show our
current inability to meet global demand, much less a future greater demand.
Citing a trend away from food aid as a disaster relief tool to one of chronic
support amidst food shortage, Brown and Kane find a "downward spiral"
(44) in which developing countries have growing foreign exchange deficits
and no development capacity to dig themselves out or increase domestic incomes.
Additionally, they point to a second trap in which population growth, agriculturally-driven
environmental degradation and poverty have joined in a mutually reinforcing
decline in the incomes of the poorest nations (45). Thus, Brown and Kane
conclude that the era of declining grain prices and increasing yields has
likely met its demise at the hands of population growth and ecological constraints
on output growth (48). As such, the authors would likely conclude that we
will not be able to feed a population of 9 billion since the instability
of our already unsustainable food system currently leaves millions malnourished
and without security about one's next meal.
Thus, optimism with regard to our ability to feed a population substantially
larger than that of today is plagued by serious caveats regarding our ability
to increase resource stewardship through new policies and our ability to
reduce demand from projected peaks by taking control of population growth
rates in the developing nations. There is an underlying battle between ecological
pessimism and technological optimism. Both Gilland and Rosegrant and Sombilla
present arguments for optimism via our ability to overcome resource constraints,
although with certain caveats about policy contributions. Brown and Kane,
in contrast, take a more widely pessimistic view in light of recent declines
in agricultural productivity growth, the unsustainable basis of today's
production and our current inability to effectively distribute both technological
and food resources to the people most in need, deepening a cycle of poverty
and economic divergence which will make future food trade all the more inadequate.
All in all, no one is unflinchingly optimistic that feeding 9 billion people
an adequate diet will be easy. The authors agree that meeting the challenge,
if possible, will require a substantial amount of foresight, political will
and wise resource management in order to avoid the disastrous potential
for a collapse in productivity due to overstressing the Earth's ecological
systems and resources.
Gilland, Bernard (2002), "World Population and Food Supply: Can Food
Production Keep Pace with Population Growth in the Next Half-Century?",
Food Policy v27, n1 (February 2002): 47-63 .
Lester Brown and Hal Kane, "Food Insecurity" in Full House,
Reassessing the Earth's Population Carrying Capacity, W. W. Norton Company,
New York, 1994, Ch 2, pp. 37-48.
Rosegrant, Mark W.; Sombilla, Mercedita A. (1997) "Critical Issues
Suggested by Trends in
Food, Population, and the Environment to the Year 2020" American
Journal of Agricultural Economics v79, n5 (1997): 1467-1470.