Essay on Population Growth & Its Impacts
- Population through ages
- Rapid growth of population in 20″‘ century due to variation in death &birth rates
- The most populated countries
- The speed of population growth
- Stress on grain production.
- Scarcity of fresh water
- Diminishing of oceanic ﬁsh catch
- Limiting meat production
- Natural Recreation Areas.
- Killing of forest
- Threat to biodiversity
- Climate change – a serious hazard
- Energy shortage
- Waste problem
- Rapid increase in unemployment
- Income distribution
- Housing & education problem
During the ﬁrst 2 million or so years of its history the human population was a minor element in the world ecosystem, with at most 10 million members. ln the New Stone Age, less than 10,000 years ago, the number of humans began to increase more rapidly. The rough equilibrium maintained before Neolithic times gave way when the human population developed agriculture and animal husbandry and no longer had to spread out in search of game. With the abandonment of a hunting-gathering way of life and the rise of permanent settlements and eventually cities, the human population underwent dramatic growth. By the beginning of the Christian era it had reached 250 million, and by 1650, half a billion. ‘
Growth of population during 20th century was very rapid. In 1994 the total world population was estimated at about 5.6 billion people. It increased nearly by 4 billions of people during past 100_years. The most signiﬁcant world trend is that death rates are currently falling in poor and rich countries alike, while birth rates remain high in most poor countries
and low in most rich ones. Exceptions are the generally higher death rates of Africa and the high birth rates of the rich oil-producing countries.
The world’s population has doubled during the last half century, climbing from 2.5 billion in 1950 to 5.9 billion in 1998. This unprecedented surge in population, combined with rising individual consumption, is pushing our claims on the planet beyond its natural limits.
The United Nations projects that human Population in 2050 will range between 7.7 billion and 11.2 billion people. We use the United Nations‘ middle-level projection of 9.4 billion (from World Population Prospects) to give an idea of the strain this “most likely” outcome would place on ecosystems and governments in the future and of the urgent need to break from the business-as-usual scenario.
This essay looks at 16 dimensions or effects of population growth in order to gain a better perspective on how future population trends are likely to affect human prospects:
From 1950 to 1984, growth in the world grain harvest easily exceeded that of population. But since then, the growth in the grain harvest has fallen behind that of population, so per-person output has dropped by 7% (0.5% a year), according to the U.S. Department of Agriculture.
The slower growth in the world grain harvest since 1984 is due to the lack of new land and to slower growth in irrigation and fertilizer use because of the diminishing returns of these inputs.
Now that the frontiers of agricultural settlement have disappeared, future growth in grain production must come almost entirely from raising land productivity. Unfortunately, this is becoming more difficult. The challenge for the world’s farmers is to reverse this decline at a time when cropland area per person is shrinking, the amount of irrigation water per person is dropping, and the crop yield response to additional fertilizer use is falling.
Since mid-century, grain area – which serves as a proxy for cropland in general — has increased by some 19% , but global population has grown by 132%. Population growth can degrade farmland, reducing its productivity or even eliminating it from production. As grain area per person falls, more and more nations risk losing the capacity to feed themselves.
The trend is illustrated starkly in the world’s four fastest-growing large countries. Having already seen per capita grain area shrink by 40%-50% between 1960 and 1998, Pakistan, Nigeria, Ethiopia, and lran can expect a further 60%-70% loss by 2050 — a conservative projection that assumes no further loses of agricultural land. The result will be four countries with a combined population of more than 1 billion whose grain area per person will be only 300-600 square meters – less than a quarter of the area in 1950.
Spreading water scarcity may be the most underrated resource issue in the world today. Wherever population is growing, the supply of fresh water per person is declining.
Evidence of water stress can be seen as rivers are drained dry and ‘water tables fall. Rivers such as the Nile, the Yellow, and the Colorado have little water left when they reach the sea. Water tables are now falling on every continent, including in major food-producing regions. Aquifers are being depleted in the U.S. southern Great Plains, the North China Plain, and most of India.
The intemational Water Management Institute projects that a billion people will be living in countries facing absolute water scarcity by 2025. These countries will have to reduce water use in agriculture in order to satisfy residential and industrial water needs. In both China and India, the two countries that together dominate world irrigated agriculture, substantial cutbacks in irrigation water supplies lie ahead.
A ﬁvefold growth in the human appetite for seafood since 1950 has pushed the catch of most oceanic ﬁsheries to their sustainable limits or beyond. Marine biologists believe that the oceans cannot sustain an annual catch of much more than 93 million tons, the current take.
As we near the end of the twentieth century, over-ﬁshing has become the rule, not the exception. Of the 16 major oceanic ﬁsheries, 11 are in decline. The catch of Atlantic cod – long a dietary mainstay for western Europeans — has fallen by 70% since peaking in t1 968. Since 1970, blueﬁn tuna stocks in the West Atlantic have dropped by 80%.
With the oceans now pushed to their limits, future growth in the demand for seafood can be satisﬁed only by ﬁsh farming. But as the world turns to aquaculture to satisfy its needs, ﬁsh begin to compete with livestock and poultry for feedstuffs such as grain, soybean meal, and ﬁsh meal.
The next half century is likely to be maiked by the disappearance of some species from markets, a decline in the quality of seafood caught, higher prices, and more conﬂicts among countries over access to ﬁsheries. Each year, the future oceanic catch per person will decline by roughly the amount of population growth, dropping to 9.9 kilograms (22 pounds) per person in 2050, compared with the 1988 peak of 17.2 kilograms (37.8) pounds).
When incomes being to rise in traditional low-income societies, one of the ﬁrst things people do is diversify their diets, consuming more livestock products.
World meat production since 1950 has increased almost twice as fast as population. Growth in meat production was originally concentrated in western industrial countries and Japan, but over the last two decades it has increased rapidly-in East Asia, the Middle East, and
Latin America. Beef, pork, and poultry account for the bulk of world consumption.
Of the world grain harvest of 1.87 billion tons in 1998, an estimated 37% will be used to feed livestock and poultry, producing milk and eggs as well as meat, according to the U.S. Department of Agriculture. Grain fed to livestock and poultry is now the principal food reserve in the event of a world food emergency.
Total meat consummation will rise from 211 million tons in 1997 to 513 million tons in 2050, increasing pressures on the supply of grain.
From Buenos Aires to Karachi, dramatic population growth in the world’s major cities — and the sprawl and pollution they bring — threaten natural recreation areas that lie beyond city limits. On every continent human encroachment has reduced both the size and the quality of natural recreation areas.
ln nations where rapid population growth has outstripped the carrying capacity of local resources, protected areas become especially vulnerable. Although in industrial nations these areas are synonymous with camping, hiking, and picnics in the country, in Asia, Africa, and Latin America most national parks, forests, and preserves are inhabited or used for natural resources by local populations.
Migration-driven population growth also endangers natural recreation areas in many industrial nations. Everglades National Park, for example, faces collapse as millions of newcomers move into southern Florida.
Longer waiting lists and higher user fees for fewer secluded spots are likely to be the tip of the iceberg, as population growth threatens to eliminate the diversity of habitats and cultures, in addition to me peace and ‘quiet, that protected areas currently offer.
Global losses of forest area have marched in step with population growth for much of human history, but an estimated 75% of the loss in global forests has occurred in the twentieth century.
In Latin America, ranching is the single largest cause of deforestation. ln addition, overgrazing and over-collection of ﬁrewood which are often a function of growing population – are degrading 14% of the world’s remaining large areas of virgin forest.
Deforestation created by the demand for forest products tracks closely with rising per capita consumption in recent decades. Global use of paper and paperboard per person has doubled (or nearly tripled) since 1961.
The loss of forest areas leads to a decline of forest services. These include habitat for wildlife; carbon storage, which is a key to regulating climate and erosion control, provision of water across rainy and dry seasons, and regulation of rainfall.
We live amid the greatest extinction of plant and animal life since the dinosaurs disappeared 65 million years ago, at the end of the Cretaceous period, with species losses at 100 to 1,000 times the natural rate.- The principal cause of species extinction in habitat loss, which tends to accelerate with an increase in a country’s population density.
A particularly productive but vulnerable habitat is found in coastal areas, home to 60% of the world’s population. Coastal wetlands nurture two-thirds of all commercially caught ﬁsh, for example. And coral reefs have the second-highest concentration of biodiversity in the world, after tropical rain forests. But human encroachment and pollution are degrading these areas. Roughly half of the world’s salt marshes and mangrove swamps have been eliminated or radically altered, and two- thirds of the world’s coral reefs have been degraded, 10% of them “beyond recognition”. As coastal migration continues – coastal dwellers could account for 75% of world population within 30 years – the pressures on these productive habitats will likely increase.
Over the last half century, carbon emissions from fossil-fuel burning expanded at nearly twice the rate of population, boosting atmospheric concentrations of carbon dioxide, the principal greenhouse gas, by 30% over pre-industrial levels.
Fossil-fuel use accounts for roughly three-quarters of world carbon emissions tend to occur where economic activity and related energy use is projected to grow most rapidly. Emissions in China “are projected to “grow over three times faster than population in the next 50 years due to a booming economy that is heavily reliant on coal and other carbon-rich energy sources?
Emissions from developing countries will nearly quadruple over the next half century, while those from industrial nations will increase by 30% according to the Intergovernmental Panel on Climate Change and the U.S. Department of Energy. Although annual emissions from industrial countries are currently twice as high as from developing ones, the latter are on target to eclipse the industrial world by 2020.
The global demand for energy grew twice as fast as population over the last 50 years. By 2050, developing countries will be consuming much more energy as their populations increase and become more affluent.
When per capita energy consumption is high , even a low rate of population growth can have signiﬁcant effects on total energy demand. Ln the United States, for example, the 75 million people projected to be added to the population by 2050 will boost energy demand to roughly the present energy consumption of Africa and Latin America.
World oil production per person reached a high in 1979 and has since declined by 23%. Estimates of when global oil production will peak range from 2011 to 2025, signalling future price shocks as long as oil remains the world’s dominant fuel.
In the next 50 years, the greatest growth in energy demands will come where economic activity is projected to be highest: in Asia. Where consumption is expected to grow 361%, though population will grow by just 50%. Energy consumption is also expected to increase in Latin America (by 340%) and Africa (by 326%). in all three regions, local pressures on energy sources, ranging from forests to fossil fuel reserves to waterways, will be signiﬁcant.
Local and global environmental effect of waste disposal will likely worsen as 3.4 billion people are added to the world’s population over the next half century. Prospects for providing access to sanitation are dismal in the near to medium term.
A growing population increases society’s disposal headaches the garbage, sewage, and industrial waste that must be gotten rid of. Even where population is largely stable – the case in many industrialized countries – the ﬂow of waste products into landless and waterways generally continues to increase. Where high rates of economic and population growth coincide in coming decades, as they will in many developing counters, mountains of waste will likely pose difficult disposal challenges for municipal and national authorities.
Since 1950, the world’s labour force has more than doubled from 1.2 billion people to 2.7 billion – outstripping the growth in job creation. Over the next half century, ‘the world will need to create more than 1.9 billion jobs in the developing world just to maintain current levels of employment.
‘ While population growth may ‘boost labour demand (through economic activity and demand for goods), it will most deﬁnitely boost labour supply. As the balance between the demand and supply of labour is tipped by population growth, wages tend to decrease. And in a situation of labour surplus, the quality of jobs may not improve as fast, for workers will settle for longer hours, fewer beneﬁts, and less control over work activities.
As the children of today represent the workers of tomorrow, the interaction between population growth and jobs is most acute in nations with young population. Nations with more than half their population below the age of 25 (e.g., Peru, Mexico, Indonesia, and Zambia) will feel the burden of this labour ﬂood. Employment is the key to obtaining food, housing, health services, and education, in addition to providing self- respect and self-Fulﬁlment.
incomes have risen most rapidly in developing countries where populations has slowed the most, including South Korea, Taiwan, China, Indonesia, and Malaysia. African countries, largely ignoring family planning, have been overwhelmed by the sheer numbers of young people who need to be educated and employed.
If the world cannot simultaneously convert the economy to one that is environmentally sustainable and move to glower population trajectory, economic decline will be hard to avoid.
The ultimate manifestation of population growth outstripping the supply of housing is homelessness; The United Nations estimates that at least 100 million of the world’s people – roughly equal to the population of Mexico-have no home; the number tops 1 billion of squatters another with insecure or temporary accommodation are included.
Unless population growth can be checked worldwide, the ranks of the homeless are likely to swell dramatically.
In nations that have increasing child-age populations, the base pressures on the educational system will be severe. In the world’s 10 fastest- growing countries, most of which are in Africa and the Middle East, the child-age population will increase an average of 93% over the next 50 years. Africa as a whole will see its school-age population grow by 75% through 2040.
If national education systems begin to stress lifelong learning for a rapidly changing world of the twenty-ﬁrst century, then extensive provision for adult education will be necessary, affecting even those countries with shrinking child-age populations.
Such a development means that countries which started population-stabilization programs earliest will be in the best position to educate their entire citizenry.
Today’s cities are growing faster: It took London 130 years to get from 1 million to 8 million inhabitants; Mexico City made this jump, in just 30 years. The w8rld’s urban population as a whole is growing by just over 1 million people each week. This urban growth is fed by the natural increase of urban populations, by net migration from the country-side, and by villages or towns expanding to the point where they become cities or they are absorbed by the spread of existing cities.
lf recent trends continue, 6.5 billion people will live in cities by 2050, more than the world’s total population today Actions for Slowing Growth: As we look to the future, the challenge for world leaders is to help countries maximize the prospects for achieving susceptibility by keeping both birth and death rates low. In a world where both grain output and ﬁsh catch per person are falling, a strong case can be made on humanitarian grounds to stabilize world population.
What is needed is an all-out effort to lower fertility. particularly in the high-fertility countries, while there is still time. We see four key steps in doing this:
Assess Carrying Capacity: Every national government needs a carefully articulated and adequately supported population policy, one that takes into account the country’s carrying capacity at whatever
consumption level citizens decide on. Without long-term estimates of available cropland, water for irrigation, and likely yields, governments are simply ﬂying blind into the future, allowing their nations to drift into a world in which population growth and environmental degradation can
lead to social disintegration. -=
There is a urgent need to ﬁll the family planning gap. This is a high-payoff area. ln a world where population pressures are mounting, the inability of 120 million of the world’s women to get family-planning services is inexcusable. A stumbling block: At the international Conference on Population and Development in Cairo in 1994, the industrialized countries agreed to pay V one-third of. the costs for reproductive-health services in developing countries. So far they have failed to do so.
Educating young women is a key to success to check population explosion. Educating girls is a key to accelerating the shift to smaller families. ln every society for which data are available, the more education women have, the fewer children they have. Closely related to the need for education of young females is the need to provide equal opportunities for women in all phases of national life.
“Have Just Two Children” must be the motto. lf we are facing a population emergency, it should be treated as such. lt may be time for a campaign to convince couples everywhere to restrict their childbearing to replacement-level fertility.