Apocalypse when? Population growth and food supply in South Asia

Food demands for staple grains are expected to almost double over the next 25 years in South Asia, due to population growth and increased standards of living. Trends in the mid-1990s suggest that neither pessimism nor optimism prevails in the region. There is wide diversity among and within countries. Trends suggest that population densities are already the highest in the world, and the amount of arable land is declining. Urban growth has moved onto farm land and farmers have been pushed onto more marginal lands or have become landless. Land intensification has produced mixed results. Cereal production per capita has increased since the 1950s in India, with about 75% of the region's population, but Pakistan's increases were not sustained into the 1980s. Average daily caloric intake per person in the region of 2214 is below the level in Sub-Saharan Africa. In Bangladesh, levels are particularly worrisome at 2037. The environmental impact has not been easily quantified, but experts have suggested that pressure on farm land has contributed to loss of soil fertility and water resource loss. Further intensification of farming is feasible, but difficult and more expensive than in the past. Regardless of production problems and solutions, there is also the very real problem of poor food distribution and lack of purchasing power. Farm management skills must be utilized, if environmental degradation is to be avoided. There is the added unknown of what climate changes will occur and how agricultural production will be affected. The policy implications are that increased food production must be made a political priority. Policies must support agricultural research into improved technologies and support distribution of technological advances to a wider number of farmers. Rural infrastructures such as roads, market outlets, and credit agencies must be established. Policies must be removed that disadvantage farmers, such as inappropriate subsidies for irrigation water, inadequate tenure agreements, and price setting. Slowing population growth provides time to adjust to expanding production and saving the environment.     

Land and leña: linking transnational migration, natural resources, and the environment in Guatemala

This article examines the relationships between international migration, natural resources, and the environment. Rather than looking at environmental change as a cause of population movements, the article reveals how migration affects the environment in sending countries. Empirically, we rely on a case study in Guatemala. Although migrants and cash remittances make significant contributions to Guatemala’s changing economy, little is known about the relationships between migration and the environment in this Central American country—a country, which continues to have a large rural population and that relies heavily on its natural resources. Drawing on ethnographic research and household surveys in a Maya community, we reveal how migrants and their earnings, as well as their ideas, behavior and attitudes, affect land use, land cover, and firewood use. We reveal, for example, how in addition to investments in land for home building and pick-up trucks to help improve agricultural production, some migrant households purchase more land and often dedicate it to the cultivation of vegetable crops for local and foreign markets. Cultural practices and beliefs directly linked to land and the environment, particularly maize cultivation, also alter due to migration processes. And, despite the ability of migrant households to transition to more efficient fuels like liquid propane gas (LPG), we show how they continue to use firewood. In all, the study contributes important insights into the environmental implications of migration.     

Land grabbing: a preliminary quantification of economic impacts on rural livelihoods

Global demands on agricultural land are increasing due to population growth, dietary changes and the use of biofuels. Their effect on food security is to reduce humans’ ability to cope with the uncertainties of global climate change. In light of the 2008 food crisis, to secure reliable future access to sufficient agricultural land, many nations and corporations have begun purchasing large tracts of land in the global South, a phenomenon deemed “land grabbing” by popular media. Because land investors frequently export crops without providing adequate employment, this represents an effective income loss for local communities. We study 28 countries targeted by large-scale land acquisitions [comprising 87 % of reported cases and 27 million hectares (ha)] and estimate the effects of such investments on local communities’ incomes. We find that this phenomenon can potentially affect the incomes of ~12 million people globally with implications for food security, poverty levels and urbanization. While it is important to note that our study incorporates a number of assumptions and limitations, it provides a much needed initial quantification of the economic impacts of large-scale land acquisitions on rural livelihoods.     

An Optimum Population for North and Latin America

The population of North America, which now stands at nearly 300 million people, is projected to double in about 60 years, while the population of nearly 500 million people in South America is projected to double in less than 40 years. Both of these populations obtain more than 99% of their food from the land, and this percentage will increase as these populations grow. Maintaining fertile and ample land is critical if these large populations are to be fed. Soil degradation by soil erosion is a serious problem on both continents. In addition, agricultural land is being lost to urbanization and highways because of rapid population growth. Nearly a half hectare of land is needed for urbanization for each person added to the North American population; this is already causing serious problems with agriculture in some states in the United States. The land resources that are critical for food production will be especially so if the populations of both continents double to nearly 2 billion. Land resources will also be critical when both continents deplete their fossil fuels in less than 100 years and have to turn to renewable energy sources. With about 2 billion people, there will be serious shortages of food, water, and energy resources and the standard of living will significantly decline. Our assessment suggests that for a relatively high standard of living in North and South America each continent should have no more than about 200 million people, or a total of 400 million.     

A Quantitative Investigation of the Population-Land Inequality-Land Clearance Nexus

This paper provides a quantitative investigation of the population-land inequality-land clearance nexus. Drawing on the literature on farmer optimization behaviour, the study formalizes and empirically tests a model of population-induced agricultural land clearance. The model makes several assumptions about this process: (a) The rate at which agricultural land is brought into production due to rising population pressures accelerates with the level of inequality in access to land, (b) Egalitarian systems have a greater capacity to absorb rising numbers of people per unit of land area and, thus, will have lower rates of agricultural land clearance than higher ones and (c) Irrespective of its degree of egalitarianism, the capacity of any system to hold people in one place will eventually break down once a critical population threshold is reached. Due to their lower population absorptive capacity, this level will be reached sooner under unequal systems of land distribution. Thus, the model also hypothesizes that the stimulatory impact of population growth on the demand for new land will exhibit a non-linear threshold pattern. For the farmer, the decision to clear a new plot of land will reflect these population-inequality interactions: Earnings from farming in settled areas will tend to fall as population densities and inequality in access to land increase. Time series results confirm that rural population growth is a significant factor driving agricultural land clearance in many of the 59 developing countries of our sample. Results also suggest that this rate of clearance is largest in countries with highly inegalitarian patterns of distribution. In contrast, cross-sectional regression results do not suggest any direct role for land inequality in population-agricultural land use outcomes. Contrary to the models assumption that this relationship should follow a non-linear threshold pattern, cross-sectional results also find no evidence that the absorptive capacity of highly densely populated land systems has been reached on average. However, they do provide support for an indirect linear relationship: Population induced agricultural land clearance is significantly magnified as inequality in access to land increases. Drawing on the empirics of the growth-inequality literature, the study suggests that this magnifying role may be linked to inequalitys impact on the assets of the poor. That is, by undermining the capacity of the rural poor to make productive investments in the land base, inequality in land distribution mediates population pressures in a way that affects both the quality and quantity of assets available to the poor to raise incomes, invest in skills accumulation, and spur demand in the rural economy as a whole.     

Population growth,changing agricultural practices,and environmental degradation in Zaire

This paper examines linkages between the demographic changes taking place in Zaire, particularly overall population growth and rapid urbanization, changes in agricultural practices, and related environmental degradation. Pressures to feed Zaire's rapidly increasing urban population, which fall on a rural population that has been growing relatively slowly in recent years, as well as population growth and increased population density in certain areas of the country, have resulted in changes in agricultural practices that are described in the paper. These changes in turn are leading to declining soil fertility, deforestation, and degradation of the natural resource base. Given present technology and the state of Zaire's economy, the changes in agricultural practices that have emerged in response to population growth, increased population density, and growth in demand for food production do not appear to be sustainable in the long run.     

Countries with Rapid Population Growth and Resource Constraints: Issues of Food,Agriculture, and Development

Recent long‐term demographic projections suggest a fast deceleration of global population growth and the eventual peaking of world population later in this century at about 9.2 billion, roughly 50 percent above the present level. Some low‐income and food‐insecure countries, however, have projected populations in 2050 that are multiples of present ones. In some of these countries agriculture must play a leading role in their development efforts because they have high economic dependence on that sector. For those among them that have scarce agricultural resources, a prima facie case can be made that the high population growth rates projected may not be compatible with the development potential offered by such resources. Their demographic projections may need to be revisited, taking into account such inadequate potential. The global demographic slowdown notwithstanding, the “population explosion”‐related issues pertaining to food and agriculture will not become irrelevant but will be become increasingly localized.     

World population growth and the food supply]

The general trend in the last several hundred years has been that the speed of growth in the food supply exceeds the speed of the population growth. For the time being, 2 major problems still exist. The 1st problem is that food production is still influenced by natural conditions. For example, abnormal weather conditions may cause regional food shortages. The 2nd problem is the imbalance of food consumption by the world population. This phenomenon exists between different social classes as well as between developed and developing countries. According to statistics released by the World Bank, 1 billion suffer from malnutrition today and most of them are in developing countries. In developed countries, about half of their increase in the food supply is for feed grains, and those countries follow the policy of reducing farm land for the purpose of maintaing stabl e grain prices. Up to the present time, grain prices have been unstable, and this has become a rather heavy economic burden for numerous developing countries. Many developing countries are trying to increase grain production by increasing their arable land and promoting their cultivating techniques. However, these countries are facing the problems of finding and adequate water supply, fertilizer, and pesticides. In addition, a rapid population growth in these countries has offset their endeavors in agriculture. In recent years, these counties have realized the necessity of birth control. The world population growth rate has decreased from 2% to about 1.7% in 1981. Birth control and an increase in the food supply will bring new hope to the world's problems of overpopulation and food supply.     

At the margins: agriculture,subsidies and the shifting fate of North America’s native grassland

We examined patterns of shifting cropland cultivation in the US Great Plains from the dust bowl to the beginning of the twenty-first century, by comparing land-cover data from 400 sample sites across the region from the 1930s, 1950s, 1970s, 1990s and 2000s. The small area land-cover data were nested within 50 target counties across the region. To understand the use of marginal land for cultivation since the Great Depression, we argue, requires consideration of the long term dynamics of demography, technology and policy. We draw on these historical dynamics, and their interactions with programs aimed at reducing environmental impacts of agriculture, to tell the story of how and when marginal lands have been brought into use. In a multilevel panel design, macro- and micro-level covariates were used to predict levels of encroachment on marginal soils. We conclude that land retirement programs (like the Conservation Reserve Program) have had a generally stabilizing effect on the micro-level patterns of land use in recent decades, but that increased levels of encroachment on marginal soils and native grassland remain a problem in areas with higher or increasing population densities.     

Preliminary discussion on the current over-population in agriculture in China]

The population devoted to agriculture constitutes more than 80% of China's total population. This high percentage is not very common in today's world. In the last 30 years, the population devoted to agriculture has increased by 81.9%, but the area of arable land has decreased in the same period of time. This situation has created problems, such as a surplus of agricultural labor, an imbalance between the agricultural population growth and agricultural means of production, a serious contradiction between the agricultural population growth and mechanization of agriculture, an imbalance between the agricultural population growth and means of livelihood, and the current low standard of living for populations engaged in agricultural work. In order to solve the problems of overpopulation, various measures must be taken in different places. The economic structure of agriculture is to be reasonably arranged, and various operations in agriculture are to be carried out. In addition to the production of main agricultural crops, forestry, animal husbandry, the fishing industry, and family supplementary income are to be developed in order to provide more job opportunities. Communes and production teams should emphasize labor intensive plans for more profit with less investment. Agriculture should focus on intensive farming in order to increase productivity. Arable land can be expanded with reclamation projects, and water and soil conservation is necessary. The surplus agricultural population should be utilized for productive activities.     

Population distribution and economic development in Africa: The need for urbanization policies

Many countries in Africa are facing severe development problems because of high rates of population growth, stagnant or declining agricultural productivity, and increasing migration of the rural poor to large cities. Most demographic studies of Africa ignore problems arising from the spatial distribution of population and public allocation of investment. Strategic planning of the location of development investments in ways that will prevent or reduce excessive concentration of population and productive activities in large primary cities is becoming increasingly important for many African governments. In this article it is argued that the excessive growth of primary cities in predominantly rural countries can be detrimental to their economic recovery. Policies encouraging more widespread distribution of population in secondary cities and towns and policies promoting investment in physical infrastructure, marketing, small-scale manufacturing, and agroprocessing in secondary cities and towns can provide a stronger base for both rural and urban development in many African countries in the future.     

An outline of study on China's population / environment issues

Attention is given to population and growth and the impact on the environment and resources in China. Policies for managing the environment and instituting population education are also addressed. The first position paper of the National Environmental Protection Agency (NEPAC) on June 2, 1990 is summarized. The population of China was 1.11 billion in 1989. The rate of growth in 1988 was 14.2/1000 in 1988. 91% live in the southeast on 43% of the land. Land area is 9.6 million square miles. 65% can be made arable, and 14% is cultivated. China has 7% of the world's arable land and 20% of the world's population. Population growth has reduced arable land/captia. The impact on forests has been deforestation. 13% of land is currently forested, and timber reserves encompass 9.14 billion cubic meters, or 9 cubic meters/person. The demand for firewood and timber will increase. The impact on grasslands has been overgrazing and desertification at a current rate of 1560 square kilometer/year. The impact on energy resources is a greater demand for coal which will increase and thus increase pollution of the environment. The impact on water resources is greater demand and increased pollution. Water resources are 2700 cubic meters/person or less than the world average. 26.8 billion tons of waste water were industrially discharged out of 36.8 billion tons. 436 of the 532 rivers are polluted. The impact on the environment is a decreased standard of living. NEPAC reported that air pollution was slightly reduced in 4% of the cities in 1988, increased in 4%, and stable in the remaining cities. Water quality improved through the lowering of industrial waste water discharges, but 72% of river segments are still above the standards. Each major river system is discussed. Noise increased, and industrial solid wastes increased. Forest reserve is 9.141 billion cubic meters; the man-made forest has increased. The loss of grasslands is .13 million hectares/year. Cultivated land is 95.72 million hectares, but 100,000 hectares/year are damaged by natural disasters and 6 million are polluted by industrial wastes. 606 nature preserves have been established. In 1989, a complete legal system of environmental protection was established and investment increased.     

Population and housing

The analysis described here was carried out in response to a political crisis in Australia. In 1994, a Member of Parliament who opposed the use of foreign aid funds for family planning programs blocked the passage of the national budget. The impasse was resolved through a compromise. The use of foreign assistance for population activities was frozen pending an independent inquiry into the impact of population on economic development. A team of nine researchers prepared background papers on population and economic development, health, education, food supply, housing, poverty, the environment, family planning, and human rights. The overall conclusion of the inquiry was that slower population growth will yield more rapid development in most countries, especially in relatively poor, agricultural nations. The purpose of this contribution to the inquiry was to assess how population growth was affecting the housing sector and, in turn, economic development. Among other questions, does population growth increase the demand for residential land, housing, and urban infrastructure? Demographic methods were critical to answering the questions, especially assessing the impact of population growth on the demand for housing.     

Population control and environment protection]

Although many factors cause environmental pollution and damage, the most important and basic factor is a rapidly increasing population. Therefore, a balanced development of population and environment is essential. The pressure a rapidly increasing populaton exerts on the environment has many aspects. The pressure of population on land resources results in increased land use and increased insecticide use due to increased insect tolerance leading to decreased productivity of cultivated land, increased desert formation, and decreased food supply. Population pressure on forest resources leads to land erosion; one of the major causes of the 1981 flood in Sichuan was attributed to excessive logging activities. Demand for fuels (firewood, straws, animal manures) by an increasing population leads to decrease in natural fertilizers, decreased food production, and energy shortage in rural areas. Population pressure on cities leads to air, water, noise and other environmental pollution as well as decrease in housing facilities and in green vegetation. Problems resulting from population pressures on industrial development include industrial and environmental pollution and unemployment. Population increases and accompanying industrial activities affect the weather which in turn affects the quality of agriculture, forests, and lakes. Thus, if unchecked, atmospheric carbon dioxide level would double by the middle of the next century, which would lead to increase in atmospheric temperature with disastrous consequences. Therefore, a well planned program for population control is essential for achieving decent quality of life.     

Population,resources, environment: an uncertain future

This issue analyzes the economic and environmental consequences of rapid population growth in developing countries (LDC), the population decline in developed countries, the limits that life on a finite planet impose on economic and demographic expansion and progress, and the proper governmental response to promote the welfare of its current and future citizens. The links between population growth, resource use, and environmental quality are too complex to permit straightforward generalizations about direct causal relationships. However, rapid population growth has increased the number of poor people in LDC, thus contributing to degradation of the environment and the renewable resources of land, water, and nonhuman species on which humans depend. Demands of the rich industrial countries have also generated environmental pressures and have been foremost in consumption of the nonrenewable resources of fossil fuels, metals, and nonmetallic minerals. On the other hand, population and economic growth have also stimulated technological and management changes that help supply and use resources more effectively. Wide variations in the possible ultimate size of world population and accelerating technological change make future interrelationships of population, resources, and the environment uncertain as well as complex. Those interrelationships are mediated largely by government policies. Responsible governments can bring about a sustainable balance in the population/resource/environment equation by adopting population and development policies that experience has shown could reduce future population numbers in LDC below the additional 5 billion indicated in current UN medium projections. This coupled with proven management programs in both LDC and developed countries could brake and reverse the depletion and degradation of natural resources.     

World food resources and population: the narrowing margin

This bulletin examines the narrowing margin between global food production and population growth. Between 1950 and 1971, world grain production nearly doubled and per capita production increased 31%. During the 1970s, gains in output barely kept pace with population growth, consumption/person declined in sub-Saharan Africa and parts of Asia, food prices were volatile, and over 100 food deficit countries came to depend on the exportable surplus of North America, now the only major grain exporting region. The world fish catch levelled off in the early 1970s and beef production, still dependent mainly on grassland grazing, levelled off in the mid-1970s. With little new land left to plow, satisfying increased food demand now depends on sharp increases in yields on existing crop land. Worldwide, this effort is hampered by loss of topsoil and irrigated land, conversion of cropland to nonfarm uses, rising energy costs, inefficient agrarian structures, particularly in the Soviet Union, the falling yield response to chemical fertilizers in agriculturally advanced countries, and the emerging competition between food and agriculturally based energy crops. Green Revolution successes in some developing countries deomonstrate that, given the right inputs, 3rd world farmers can increase crop yields dramatically. Feeding the world's poor also requires more equitable income and food distribution, including a reduction in the proportion of grain and fish consumed indirectly as livestock products by the affluent. Most important in meeting food needs on a finite planet is braking population growth. The author concludes that every effort should be made to stabilize world production at abour 6 billion by 2020, rather than 10.5 billion by 2110, as is now projected by the UN.     

Implications of population growth and urbanization on agricultural risks in China

Growing population, rapid urbanization, rising incomes, and changing consumption preferences stimulate intensification of livestock production and excessive fertilization of crops in China. We present an innovative approach that sheds light on options to prevent negative environmental consequences of food production. Trends indicate that agricultural production expansion will take place in “profitable” locations around densely populated areas, where there are generally insufficient natural resources to recycle production wastes. This will likely lead to increased environmental impacts and risks to human health, with the largest impacts in close proximity to population hotspots. We identify trends in Chinese agricultural production and devise and compare feasible mitigation scenarios. We present a spatial allocation procedure that facilitates management of agricultural production expansion, accounting for environmental and health constraints. This procedure, based on behavioral principles, uses a spatial risk preference structure induced by local conditions, including environment, production, and demand, with important research and policy implications.     

Population and water resources: a delicate balance

Various avenues exist to minimize the effects of the current water crisis in some regions of the world and the more widespread problems that will threaten the world in the future. Active management of existing water resources and a reduction in population growth in water-scarce areas are needed to minimize the effects of the water crisis. National boundaries do not effect water systems. Cooperation and commitment of local, national, and international governments, institutions, and other organizations are needed to manage water systems. Development in each country must entail conscientious and effective balancing of unavoidable manipulations of the land and the unavoidable environmental impacts of those manipulations. The conditions of environmental sustainability must include protection of land productivity, ground water potability, and biodiversity. Humans must deal with these factors either by adopting methods to protect natural systems or by correcting existing damage and reducing future problems. They need to understand the demographic forces in each country so they can balance society's rising needs for clean water with the finite amount of water available. Factors affecting future needs at all levels include rapid rural-urban migration, high fertility, and changing patterns of international population movement. Given an increased awareness of global water systems, demographic trends, and active management of resources, the fragile balance between population and water can be maintained.     

Africa's expanding population: old problems,new policies

Sub-Saharan Africa faces an historic challenge: to achieve economic and social progress while experiencing extraordinary population growth. With an estimated 1989 population of 512 million, the 42 countries of sub-Saharan Africa have the highest birth and death rates of any major world region. While death rates have fallen since the 1960s, persistently high birth rates yield annual growth rates above 3% in many countries. The United Nations projects that the region's population will increase 2.7 times by 2025--to 1.4 billion. Throughout the region, population has outstripped economic growth since the mid-1970s. In addition, many African countries are experiencing an epidemic of AIDS (Acquired Immunodeficiency Syndrome). The extent and demographic impact of the epidemic still are unknown, but disturbing social and political effects are already being felt. The region's population growth will slow only when African couples begin to have fewer children. The average number of children per woman ranges from 6 to 8 for most countries. The Africans' preference for large families is deeply rooted in the culture and fed by the perceived economic benefits they receive from their children. Economic stagnation during the 1980s prompted many national governments to recognize that rapid population growth was hindering their socioeconomic development. The political climate has shifted away from pronatalist or laissez-faire attitudes toward official policies to slow population growth. The policy formation process--detailed here for 4 countries (Zambia, Nigeria, Zaire, and Liberia)--is ponderous and beset with political and bureaucratic pitfalls, However, policy shifts in more and more countries combined with evidence of increased contraceptive use and fertility downturns in a few countries give some hope that the region's extraordinary population growth may have peaked and will start a descent. Whatever the case, the decade of the 1990s will be crucial for the future of sub-Saharan Africa.     

中国未来人口发展的粮食安全与耕地保障

中国人口发展的粮食安全与耕地保证程度研究表明,随着人口增长和消费扩张,中国未来的耕地规模和人均耕地面积会进一步下降,人均粮食消费水平和粮食需求总量将进一步提高;2020年在人均粮食420~435kg的消费水平上,基于18亿亩耕地保证的粮食生产能力可以基本满足14.36亿人口的粮食需求;在人均450kg的消费水平上,中国未来耕地的粮食生产能力足以支持人口高锋时间的14.73亿人,但受耕地资源有限约束,人均粮食占有水平很难有进一步提高。从耕地、粮食与人口关系看,中国未来人口的粮食安全必须向食物安全转变,从耕地资源约束的粮食生产与人口增长驱动的食物消费两端着眼:一方面要重视耕地与粮食安全——藏粮于土,全面提高土地资源综合生产能力;一方面要关注食物与消费安全——倡导适度消费,建立动植物并重型食物结构;从生产与消费两方面来认识和解决中国中长期人口发展的食物安全与耕地保障问题。