The effects of World Population Increase
The effects of the world population growth well into the 21st century will have both local and global effects on the natural environment and on human populations themselves. Discuss this statement.
The world's population is growing by nearly 80 million people per year. While population growth rates have slowed since their peak in the 1960s, the numbers being added to the population each year continue to be huge, in part because of the growth in the numbers of people of reproductive age. At current rates of birth and death, the world's population is on a trajectory to double in 49 years.
The median projection of population size by the U.N. Population Division envisions that population growth rates will decline over the coming several decades. But even if that median projection is achieved, the number of people expected to be added to the world's population in the next 50 years will be almost as large as the number added in the last 50 years. However some scientists such as Julian Simon believe this won't be a problem.
His 1981 book "The Ultimate Resource" is a criticism of the conventional wisdom on population growth, raw material scarcity and resource consumption. Simon argues that our notions of increasing resource-scarcity ignore the long term declines in wage adjusted raw material prices. Viewed economically, he argues, increasing wealth and technology make more resources available; although supplies may be limited physically they may be viewed as economically indefinite as old resources are recycled and new alternatives are developed by the market. Simon challenged the notion of a pending Malthusian catastrophe: that an increase in population has negative economic consequences; that population is a drain on natural resources; and that we stand at risk of running out of resources through over-consumption. Simon argues that population is the solution to resource scarcities and environmental problems, since people and markets innovate.
However that magnitude of increase, coming on top of the unprecedented growth that has occurred in the last half-century, will be felt in all aspects of life. It will further stress already strained ecological systems and worsen poverty in much of the developing world, thus aggravating threats to international security. Population growth is not the only threat facing humanity, but it will be a major contributor to the crises that await us in the coming century.
Firstly there are environmental threats: The expansion of human activity and associated loss of habitat are the leading causes of the unprecedented extinctions of plant and animal species worldwide. The loss of biological diversity leads to instability of ecological systems, particularly those that are stressed by climate change or invasion of non-native species.
Massive rural to urban migration in much of the developing world has overwhelmed water treatment systems, resulting in water pollution that leads to intolerable health conditions for many people. Despite this migration, rural populations are also growing, leading to overuse of land and resultant erosion of hillsides and silting of rivers, as typified by Madagascar, Nepal and Haiti.
The same pressures are hastening the destruction of vast forest areas and loss of wildlife habitat. The loss of forests also reduces the ability of the ecosystem to combat global warming. Carbon dioxide that would be absorbed by trees ...
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Massive rural to urban migration in much of the developing world has overwhelmed water treatment systems, resulting in water pollution that leads to intolerable health conditions for many people. Despite this migration, rural populations are also growing, leading to overuse of land and resultant erosion of hillsides and silting of rivers, as typified by Madagascar, Nepal and Haiti.
The same pressures are hastening the destruction of vast forest areas and loss of wildlife habitat. The loss of forests also reduces the ability of the ecosystem to combat global warming. Carbon dioxide that would be absorbed by trees instead stays in the atmosphere.
On a global basis, emissions of greenhouse gases, such as carbon dioxide, are rising rather than falling, despite the international agreements designed to reduce emissions. Given this trend, many scientists believe that global warming will accelerate during this century, with consequences including rising sea levels, growing weather severity, and disruption of agriculture.
Greenhouse gas emissions are increasing in developing countries, where populations are expanding most rapidly. In some of these countries, energy consumption and production of greenhouse gases is rising on a per capita basis as the countries' economies expand. In most, there is an understandable desire to increase living standards by increasing production and per capita consumption of energy and resources. Median projections of expanding economic activity in developing countries indicate that the developing world will be producing more greenhouse gases than the developed countries by the year 2020. At the same time, the developed countries are generally failing to make progress on reduction of greenhouse gas emissions, in part because of continuing population increases, especially in the United States.
Given the trends in population, energy and resource consumption, combined with technological innovations, the adverse human impact on the global ecosystem could triple or quadruple by the year 2050.
Rapid population growth aggravates poverty in developing countries by producing a high ratio of dependent children for each working adult. This leads to a relatively high percentage of income being spent on immediate survival needs of food, housing, and clothing, leaving little money for purchase of elective goods or for investment in the economy, education, government services, or infrastructure. Lack of available capital continues to frustrate the attempts of many developing countries to expand their economies and reduce poverty.
Only about 20 percent of the current world's population has a generally adequate standard of living. The other 80 percent live in conditions ranging from mild deprivation to severe deficiency. This imbalance is likely to get worse, as more than 90 percent of future population growth is projected for the less developed countries.
The continent with the most rapid population growth, Africa, is actually growing poorer. African's per capita gross domestic product of $510 is only 89 percent of the 1960 level. Per capita calorie intake is 20 percent below that of 1960. Every third person in Africa is chronically malnourished. The doubling time of Africa's population is 28 years. Average desired family size in sub-Saharan Africa is five children per couple.
Just as population growth contributes to poverty, population stabilization has often contributed to rapid improvements in per capita economic conditions and overall quality of life. All of the countries that have moved from developing status to developed status since World War II, according to U.N. criteria, had brought their fertility rates down close to replacement level around the times their economies began to take off. These include South Korea, Japan, Taiwan, Singapore, Barbados and The Bahamas.
Productive agricultural systems have contributed to economic progress in many countries, both developed and less developed. The Green Revolution of the 1970s enabled some developing countries to become net exporters of food. Yet, global population growth during and since the Green Revolution is continuing to consume more and more of the expanding food base, leading to a decline in per capita availability of cereal grains on a global basis over the last 15 years.
The world's agricultural systems rely substantially on increasing use of fertilizers. But now, the world's farmers are witnessing signs of a declining response curve, where the use of additional fertilizer yields little additional food product. At the same time, fertilizers and intensive cropping lower the quality of soil. These factors will more and more limit the possibilities of raising food production substantially and will, at a minimum, boost relative food prices and resulting hunger for many. So will the mounting resistance of pests to insecticides, which are used increasingly by the world's farmers. On a global basis, 37 percent of food and fibre crops are now lost to pests. At the same time, nitrogen-based fertilizers are yielding nitrous oxide, which adds to the greenhouse effect of the carbon dioxide humans produce.
As an illustration of food problems to come, Lester Brown of World Watch Institute has made projections regarding food demand by China and India through the year 2030. Because of industrialization leading to loss of agricultural land, population growth, and the demand for more meat instead of grain as incomes rise, China is projected to need to import 240 million tons of food annually by the year 2030. The same projections show India (currently an exporter of food) needing to import 30 million tons a year. Yet, total world agricultural trade is currently just 200 million tons of grain or grain equivalent, and that amount is decreasing as the exporting countries consume more and more of their own food products. Accordingly, the increasing demand for food imports by growing economies like China's will almost certainly drive the price of food up over the next 30 years, virtually ensuring that more people elsewhere will suffer from starvation. Historically, Western countries have shown no inclination to undergo a dramatic decline in their own quality of life (including greatly reducing consumption of meat and poultry) in order to assist poor countries with grain exports. And so the world is likely to witness severe starvation and economic dislocation over the next 30 years.
At the same time, shortages of water are at a crisis point in many countries. At least 400 million people live in regions with severe water shortages. By the year 2050, it is projected to be approximately two billion. Water tables on every continent are falling, as water is pumped out at far greater rates than rainwater can replenish in order to provide irrigation for agriculture. India, for example, is pumping out its underground aquifers at twice the rate of natural replenishment.
Humans are already using half of the globe's products of photosynthesis and over half of all accessible fresh water. Long before human demand doubles again, the limits of the ecosystem's ability to support people will become dramatically evident.
As mentioned earlier, population growth is a major contributor to economic stagnation through its depressing effect on capital formation. With growing numbers of young people attempting to enter the labour force, many developing countries have extraordinarily high levels of unemployment. Often high rates of unemployment give rise to severe political instability, which ultimately threatens national and international security.
In a world growing closer together, wealthier countries and regions too will find it increasingly difficult to insulate themselves from threats to their own security. The combination of poverty and violence is adding rapidly to the number of refugees seeking to move into more stable and prosperous areas. Growth of refugee and migrant populations are contributing to political instability and economic dislocation in many countries. Intelligence agencies in the U.S. and elsewhere have long recognized the implications of population growth for international security.
At the global level, human population growth is one significant cause of environmental problems - destruction of natural ecosystems, increased rate of species extinction, soil erosion, falling water tables and depletion of aquifers, pollution of rivers, seas and coastal waters, increase of harmful emissions to the atmosphere. Population growth has in my view, already taken the human population beyond the carrying capacity of the planet.
Through its adverse effect on the environment, population growth is a significant cause of the increase in the number of environmental refugees (people who can no longer secure a livelihood in their own area because of environmental problems such as desertification). The number of environmental refugees will be greatly inflated if, as expected, global warming causes sea levels to rise, inundating vast areas of densely populated land. In the past, abrupt climate temperature changes have occurred. If they occur in the future, agricultural systems may be unable to adapt fast enough, causing massive decrease in food production, which in turn will swell the number of environmental refugees. Environmental refugees may simply be displaced within a country, or they may by international migration move between nations or continents. Such disruptive movements can impede attempts to achieve sustainable development.
Some believe population growth can contribute to political instability and conflict. And the great affluence gap between the rich and poor countries has implications for migration: it fuels the desire to emigrate from poor countries, a desire which is likely to be increased as massive population growth continues in these countries. Such migration increases the potential for demographically fuelled international conflict. And declining natural resources will probably increase 'resource wars'. This in my opinion will be the toughest consequence from world population growth that our societies will have to adapt to. This was also expressed famously in 1798 by Thomas Malthus, who's "Essay on the Principle of Population as it Affects the Future Improvement of Society" warned that food production, which relied on finite factors of production could not keep up with exponential human reproduction.
