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9. Concluding remarks
Juha I. Uitto
Today's world is experiencing a growth in the human population that is unparalleled in history. The world's population has doubled since the 1950s and we have now reached a level of more than 5.6 billion people on this planet. Every year, some 90 million new people are added to this number. The "most likely" scenario forecast by the United Nations puts world population at 10 billion in the year 2050.
The pressures placed on agricultural production on a global scale are daunting. In 1961, the global arable area was 1.3 billion hectares, of which 10 per cent was irrigated. Thirty years later, the global arable area has increased by only 100 million hectares, while the share under irrigation has gone up to 17 per cent. However, even if the total arable area has increased somewhat, if one adjusts it by the number of people that have to be fed, the figure looks very different. Since 1961, the amount of arable land per capita has decreased from 0.44 hectares to a mere 0.27 hectares in 1990 (Engelman and LeRoy 1995). This already small amount of a quarter of a hectare per head is rapidly shrinking.
It is, thus, obvious that the mere increase in global population is putting fierce pressures on the ability of the Earth to feed its inhabitants. In the past decades, food production has been able to cope with the increase in the number of consumers through constantly higher output per area unit. The socalled green revolution has been instrumental in increasing the crop yields manifold and, thus, warding off hunger in many countries. However, there is now clear evidence that the yield increases have reached or will soon reach their limits, with most farmers already using improved varieties and techniques.
Take rice, for example, on which most Asians, and a large share of others in different parts of the world, rely for their staple food. Rice farming in Japan is very intensive and has served as a model to emulate for many nations. Japan's rice yields per area unit were constantly rising for the past century. This rise, however, came to a halt in 1984 after which the yields have actually fallen slightly. Evidence from other rice-growing countries, including Bangladesh, India, the Philippines, and Thailand, suggests that intensification of land use and continuous cropping of rice with two or three yields per year has actually led to a decline in unit yields (Brown and Kane 1994).
Consequently, further increases in yields will be difficult to attain without significant new technological advances. Furthermore, the "green revolution" is associated with other problems, as well, including the excessive need for irrigation water, and the reliance on fertilizers, pesticides, and other agricultural chemicals with adverse environmental effects. Similarly, usage of modern high-yielding crop varieties leads inevitably to the loss of the biological diversity inherent in traditional agricultural systems, rendering the farms more vulnerable to pests and climatic variation, at the same time as reducing the gene pool available to mankind.
With little new arable land available for clearing, farmers will mostly have to rely on existing land or, as is frequently the case, move to increasingly marginal areas. The latter increases the vulnerability of the farm land to erosion and is often associated with loss of topsoil and the encroachment of deserts.
In South-East Asia, earlier UNU research identified the inevitable population growth and the rapid economic growth as the basic constraints within which any improved environmental management must evolve (Brookfield and Byron 1993). These basic constraints form the main driving forces of environmental change in the region. The research further identified a number of present trends that are clearly unsustainable in the long run. These include the present methods of intensification of agricultural production, which are heavily dependent on the extensive use of agricultural chemicals; most land-use practices in upland areas, the importance of which will only increase in the future; urbanization with the associated lack of adequate pollution control and waste management; the increasing use of energy; and forestry practices that do not replace depleted resources, leading to the loss of biological diversity at an alarming rate.
However, even if on global and regional scales the trends are clear, at the local level there are considerable variations in the interlinkages between population growth, agricultural production, and the sustainability of the environment. Whereas in some places environmental degradation caused by over-cultivation and over-grazing has led to the destruction of the agricultural production base, causing entire villages to become environmental refugees, in others increases in smallholder population have actually led to more sustainable production practices. Such cases have recently been reported for example from Kenya in East Africa, where people reacted to the increasing population pressure by adopting improved farming practices, building terraces to fight erosion and planting trees for fuelwood (Tiffen et al. 1994).
This example demonstrates the complexity of the issue. The simplistic and deterministic notions that so often figure in the discussions and even are used as bases for policy formulation need to be modified to reflect the complex and varying conditions encountered in reality.
The Fourth UNU Global Environmental Forum was largely based on the detailed research work carried out within the international collaborative research programme on "People, Land Management, and Environmental Change," or PLEC as it is called in short, undertaken under the auspices of the United Nations University. PLEC is aimed at a systematic field-level analysis of sustainable land management and agrotechnology, and the maintenance of biological diversity in small-farm regions in the tropical and subtropical parts of the world. A basic premise of the programme is that the indigenous farming practices in the various parts of the world are frequently well-adapted to the prevailing ecological conditions and contain solutions to the issue of sustainability. The traditional farming systems are, however, under severe pressure due not only to population growth, but to various societal forces. Detailed studies are needed to understand the process and to provide policy-relevant advice to the concerned countries and organizations involved in agricultural development.
PLEC lays particular stress on the diversity of farming practices over small areas, their responsiveness to changing conditions, and adaptation to ecological variability. Cases covered at this Forum highlighted the widely varying environmental, social, economic, and political conditions that pose the framework for sustainable agricultural development in such different places as northern Thailand, Papua New Guinea, and the Amazonian floodplains. In addition, PLEC operates in other regions of the world not represented here today, including the Caribbean islands; the dynamic West African forest savanna transition zone; a selection of sites in the three Eastern African countries of Kenya, Tanzania, and Uganda; and the Chinese province of Yunnan.
In addition to the geographical distribution, importance is placed on the multidisciplinary approach. The Forum speakers come from backgrounds ranging from agriculture and the soil sciences, through geography to anthropology. Knowing the ground truth is essential, but modern tools such as satellite remote sensing and Geographical Information Systems (GIS) can be utilized to provide information on a higher scale. The combination of these approaches is indispensable to the fuller understanding of the conditions.
Other UNU research complements the PLEC programme. Notably, the long-running research programme on "Mountain Ecology and Sustainable Development" has related objectives focusing on the man-land interaction in the mountainous and highland areas of the world. Policy-oriented work is being carried out in the Hengduan mountains of China, in the Himalayas, in the mountains and highlands of Africa, and in the Andes in Latin America (e.g. Ives and Messerli 1989; Ives and Uitto 1994).
The results of UNU research are being actively fed into the policy-making process by the United Nations. The University's work is also geared towards greater capacity building in developing countries to allow the countries to better formulate and implement their policies concerning sustainable development.
The quest for sustainable development is an awesome task and it requires the participation of all sectors of society. We hope that our cooperation within research and capacity building will make a modest contribution to this task.
Brookfield, H. and Y. Byron (eds.). 1993. South-East Asia's Environmental Future: The Search for Sustainability. United Nations University Press, Tokyo, and Oxford University Press, Kuala Lumpur.
Brown, L.R. and H. Kane. 1994. Full House: Reassessing the Earth's Population Carrying Capacity. W.W. Norton & Company, New York.
Engelman, R. and P. LeRoy. 1995. Conserving Land: Population and Sustainable Food Production. Population and Environment Programme, Population Action International, Washington, DC.
Ives, J.D. and B. Messerli. 1989. The Himalayan Dilemma: Reconciling Development and Conservation. The United Nations University, Tokyo, and Routledge, London.
Ives, J.D. and J.I. Uitto. 1994. Mountain ecology and sustainable development. Global Environmental Change: Human and Policy Dimensions 4(3):261-64.
Tiffen, M., M. Mortimore and F. Gichuki. 1994. More People, Less Erosion: Environmental Recovery in Kenya. John Wiley & Sons, Chichester, UK.
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