Industrialization, economic growth, improved education systems, and greater contraception use helped bring about rapid fertility declines in southeast Asia in the last half-century. Today, rich countries have an average fertility rate below the replacement level of 2.1 children per woman. The countries that still have high fertility rates in the 21st-century tend to be in poorer countries, especially concentrated in Sub-Saharan Africa (see maps above).6 The widely-observed shift towards lower fertility and mortality rates as countries develop economically is called the demographic transition. Figure 4 shows that higher GDP per capita is associated with lower fertility rates.
There are several reasons why economic growth can lead to lower fertility. In developing countries where subsistence agriculture is the norm, children can be a source of labor and insurance, making larger families desireable.7 In places without access to modern healthcare, child mortality rates are also higher. This leads women to choose larger families in order to ensure that some of their children survive to adulthood.8 Education rates, especially among women, also tend to be lower in poor countries. With more education, women tend to marry later and are better able to access birth control, allowing them to invest more of their resources in fewer children.6
With something as personal as family size, cultural norms also play an important role. In Niger, for example, surveys found that even women with secondary schooling want 6 children on average, due to a cultural preference for large families.6 Conversely, some poor countries can see cultural shifts towards smaller family sizes even without major economic development.6 An interesting analysis in India, for example, found that TV ownership was associated with lower fertility rates. The author argues that parents were influenced by the modern, smaller families they saw portrayed as happy and successful on TV.
Public policy can also influence fertility rates, both directly and indirectly. Programs to promote family planning information and access to contraception can change fertility rates directly. A recent study of 40 high-fertility countries found that half of the difference in birth rates could be attributed to family planning efforts.9 However, since fertility is also related to other factors like healthcare and education, public policies to improve those outcomes can impact fertility rates as well.
Q: Isn’t the world overpopulated?
There have been social observers throughout history who warn that the world is headed for catastrophe due to overpopulation. In 1797, the Reverend Thomas Robert Malthus wrote his Essay on the Principle of Population to warn British elites that unchecked human procreation would lead to resource scarcity and eventual collapse. More recently, in 1968, the biologist Paul Ehrlich published his bestselling book, The Population Bomb, warning that overpopulation would lead to environmental catastrophe and mass starvation. Ehrlich’s book was published at a time when the global population was growing at its fastest rate, and many shared his fear.
Concerns about overpopulation ultimately stem from the question of how many people the Earth can support. However, the answer to that question is highly dependent on what kind of lifestyles those people lead, what technologies they use, and what social and economic institutions are in place.10 For example, the first Dutch settlers in what is now New York City would never have imagined that Manhattan Island would one day be home to 1.6 million people. That’s because the technologies that enable it, like skyscrapers and refrigeration, did not exist in the 17th century.
In his book How Many People Can the Earth Support?, Joel Cohen argues that his titular question “has no single numerical answer, now or ever.” He explains: “Because of the important roles of human choices, natural constraints and uncertainty, estimates of human carrying capacity cannot aspire to be more than conditional and probable estimates: if future choice are thus-and-so, then the human carrying capacity is likely to be so-and-so” (emphasis original).
Several studies have demonstrated the fungibility of this question. One study from a group of biologists, for example, estimated that using all the Earth’s land, we could support a population of 282 billion people.11 Even in their “save the forests” scenario, the population maximum was 150 billion. These are rather extreme thought experiments, and would create an Earth very different than today’s, but they help highlight that the Earth itself does not provide a single answer for how many people can live on it.
In general, it is safe to say that population growth increases resource pressures and leads to environmental harm, but there is no single “tipping point” or threshold that balances the human population and Earth’s resources.
Q: What would be the significance of a peak in population?
Although most human impacts on the environment continue to grow in absolute terms, many are declining at the per-capita level. For example, although total global freshwater consumption is increasing, it is increasing more slowly than the population, meaning each person is using less water today than thirty years ago. Efficiency gains have partly offset the growth in population.12 This decrease in per-capita consumption is called relative decoupling; if total water consumption begins to decline, that would be absolute decoupling.
A peak in human population offers the potential to achieve absolute decoupling, and with it major reductions in human impacts on the natural world. If the human population is no longer increasing, gains in per-capita efficiency will translate to reductions in total consumption. This “peak impact” could still occur alongside a growing population, but it would require larger efficiency gains.
Q: How is the world population expected to grow this century?
The United Nations and other organizations publish projections of how the world population could change in the coming decades. The UN’s median projection shows the world population growing to 9.7 billion by 2050 and 11.2 billion by the end of the century (see Figure 5). The high and low ends of their prediction interval suggest population is likely to be somewhere between 9.3 and 10.2 billion by 2050.
The UN and IIASA arrive at different population projections because of the different assumptions underlying their statistical models. In both models, most of the population growth this century will occur in less developed countries, mostly in Sub-Saharan Africa, where the demographic transition has not progressed very far.
The UN projections are slightly more pessimistic about the pace of demographic transition in Sub-Saharan Africa, which produces a higher projection. They base this assumption on evidence that fertility declines in Sub-Saharan Africa are occurring more slowly than other countries did at similar stages of development.13 They concede, however, that their median projections may be too high “should massive efforts to scale up family planning information, supplies and services be realized.”13
IIASA’s projections assume a slightly faster pace of fertility decline in Sub-Saharan Africa. They argue that the stalls in fertility decline observed there are likely to be temporary, delaying the demographic transition by only 5 or 10 years. The IIASA model also includes education as a third demographic dimension alongside age and sex. They argue that including this additional dimension, which has such strong predictive potential for fertility and mortality levels, increases the accuracy of their projections compared to the UN.
Q: Can we expect peak population this century?
Although the general drivers of fertility declines are known, demographers cannot know for sure if today’s high-fertility countries will follow historical patterns.6 However, governments and civil society can play a very active role in creating policy that impacts fertility rates, both directly, through family planning programs, and indirectly, by promoting economic development more broadly. Lowering fertility rates is far from the only reason to advocate for poverty reduction, access to education, and the empowerment of women.
There is a lot of uncertainty about how the world population will change this century, but there is plenty of cause to be optimistic. Both the UN and IIASA median projections see fertility rates declining in all high-fertility regions by 2050. Indeed, the only regions with any projected growth in fertility rates are wealthy countries where birth rates are much lower than replacement. Whether at 9 or 11 billion, continued efforts to promote human development could help the 21st century see the world population peak and start to decline.
Effects of Population Growth on our Environment!
One of the factors responsible for environment degradation is population growth or population density. In particular, population density plays the most important role in shaping the socio-economic environment. Its effects are felt on the natural environment also.
1. Generation of Waste:
Due to his destructive activities, man has dumped more and more waste in environment. As the man-made waste is not transformed, it causes degradation and the capacity of environment to absorb more waste is reduced. Further, waste leads to air and water pollution.
2. Threat to Biodiversity:
Due to his destructive activities, man has extracted more and more minerals from the earth. Animals have been hunted and plants have disappeared. There has been loss of biodiversity. These have led to ecological imbalance.
3. Strain on Forests:
Man has established new housing colonies. National highways and hydropower projects have been built and forests have been wiped out. These destructive activities have increased and led to ecological imbalance.
Rapid growth of population has led to urbanization which has adversely affected environment. Due to population pressure, natural resources in the cities are depleted at a fast rate due to population pressure.
Moreover, population does not have proper sanitation facilities and pure drinking water. As a result, the health of the people is adversely affected. No doubt, urbanization reduces pressure on the rural environment, but it brings with if environmental damages through industrial growth, emissions and wastes.
Underdeveloped countries are following the policy of heavy industrialisation which is causing environmental degradation. The establishment of such industries as fertilizers, iron and steel, chemicals and refineries have led to land, air and water pollution.
6. Land Degradation:
Intensive farming and excessive use of fertilizers and pesticides have led to over-exploitation of land and water resources. These have led to land degradation in the form of soil erosion, water logging and salination.
7. Transport Development:
Environmental degradation is also due to transport development in the different parts of the world. The automobiles release huge quantities of poisonous gases such as carbon monoxide, nitrogen oxides and hydrocarbons. The development of ports and harbours have led to oil spills from ships adversely affecting fisheries, coral reefs, mangroves and landscapes.
8. Climatic Change:
Climatic changes are irregular due to green house gases. The thin skin of air that surrounds the planet is being affected by human activities as never before. Urban people are still being exposed to unaccepted levels of toxic pollutants. Further, forests are still being degraded by acid deposition generated by faraway industries, and greenhouse gases continue to accumulate in the atmosphere.
Environmental degradation not only harms health but also reduces economic productivity. Dirty water, inadequate sanitation, air pollution and land degradation cause serious diseases on an enormous scale in developing countries like India.
These, in turn, reduce the productivity levels in the country. To take specific instances, water pollution has led to declining fisheries in rivers, ponds and canals in both urban and rural areas. Water shortages have reduced economic activity in towns, and cities and villages.
Soil and hazardous wastes have polluted ground water resources which cannot be used for agricultural and industrial production.
Soil degradation leading to soil erosion, drought, etc. have led to siltation of reservoirs and blocking of river and canal transport channels. Deforestation has led to soil erosion and consequent loss of sustainable logging potential.
Loss of bio-diversity has resulted in the loss of genetic resources.
Last but not the least, atmospheric changes have given rise to disruption of marine food chain, damages to coastal infrastructure due to sea-rise and regional changes in agriculture productivity due to hurricanes in seas.
Thus, environmental degradation undermines economic productivity of a nation.
Presently, environmental pollution is caused by old technology which releases gases and pollutants causing chemical and industrial pressure on environment.
Impact of Environment on Population:
Polluted environment also affects adversely the health of people.
Table 36.1 shows the types of pollution, their poisonous elements and effects on health.
Agricultural and industrial development along with urbanisation and spread of infrastructure combined with population growth has led to environmental degradation. Environmental degradation harms human health, reduces economic productivity and leads to the loss of amenities. The damaging effects of economic development on environmental degradation can be reduced by a judicious choice of economic and environmental policies and environmental investments.
We discuss some policy measures as under:
1. Control of Population Growth:
The rate of population growth should be curtailed through effective family planning measures. This is essential because the proportion of total population in the labour force will increase further in the years to come as a result of changes in the age structure of the population.
The shifting of labour force from the rural to the secondary sector requires increase in agricultural productivity. Increased agricultural productivity helps in meeting the demand for raw materials of the expanding manufacturing sector. With increased productivity, less workers are required to produce raw materials for industry and food-grains for the population.
It also increases agricultural surplus thereby raising saving and investment for economic development. So concerted efforts are needed to increase agricultural productivity through technological advancement. This will ultimately lead to commercialisation of agriculture and production for exports, thereby earning foreign exchange for further development.
2. Economic Development:
The aim of population control is not only to bring about a decline in fertility rates but also to improve the quality of life of the people. These are possible through rapid economic development. It is not an illusion to believe that a reduction in population growth will automatically raise living standards. In fact, an effective family planning policy should be integrated with measures to accelerate economic development.
As the Ninth Five Year Plan observes:
“Several of the South Asian countries have been able to achieve economic prosperity and improvement in quality of life in spite of population growth. This has been attributed to the increase in productivity due to development and utilisation of innovative technologies by the young educated population who formed the majority of the growing population.”
In the current phase of demographic transition, developing countries can also achieve economic growth and improvement in quality of life despite population growth through commercialisation of agriculture, diversified industrialisation, urbanisation, and development of infrastructure so as to increase employment opportunities, raise income levels, and saving and investment rates.
These will help the country to achieve economic transition from low economic growth (low per capita income) to high income growth and to high per capita income. This will, in turn, raise the quality of life of the people and the population will be controlled automatically.
3. Improving Health and Nutrition:
The food and nutrition security for the weaker sections in a developing country should not be considered as issues in the Nutrition Science but should be considered as part of right to work, right to health, right to education, right to information and right of the poor. In such a country, there are agricultural, health, population, nutrition, children and education policies.
On the other hand, there are fiscal and budget revisions, exports, imports, taxation, price wage, employment policies and policy related to subsidies. Ultimately, all these policies affect life of the poor, their food and nutritionist security and health. As a leading nutritionist C. Gopalan notes: “Various types of food are needed for maximum nutrition and if they are all taken together and in proper proportions (systematic balanced diet), they can provide necessary nutrients.
Guarantee of good nutrition and absence of hunger are not the same thing. Our first effort should be towards removing hunger of the poor, but our long-term goal should be to provide maximum nutrition to our people which is useful in bringing out their hereditary talents. Nutrition security is more important than food security. Nutrition security includes making our food base wider and varietal. ”
Improving health and nutrition levels is an extremely important factor contributing to the social development of a developing country. Especially the people of the weaker sections of the society who do not take adequate advantage of health, family welfare and nutrition services, should be made aware of these facilities so that their health and nutrition status can be improved.
4. Reducing Poverty:
Such development projects should be started which provide greater employment opportunities to the poor. The government should expand health and family planning services and education so as to reach the poor that will help reduce population growth. Further, making investments in providing civic amenities like the supply of drinking water, sanitation facilities, alternate habitats in place of slums, etc. will not only improve welfare but also environment.
5. Removing Subsidies:
To reduce environmental degradation at no financial cost to the government, subsidies for resource use by the private and public sectors should be removed. Subsidies on the use of electricity, fertilisers, pesticides, diesel, petrol, gas, irrigation water, etc. lead to their wasteful use and environmental problems.
Subsidies to capital intensive and highly polluting private and public industries lead to environmental degradation. Removing or reducing subsidies will bring both economic and environmental benefits to the country.
6. Clarifying and Extending Property Rights:
Lack of property rights over excessive use of resources leads to degradation of environment. This leads to overgrazing of common or public lands, deforestation, and overexploitation of minerals, fish, etc. Clarifying and assigning ownership titles and tenurial rights to private owners will solve environmental problems. Places where the use of common lands, forests, irrigation systems, fisheries, etc. are regulated and rules for their proper use are laid down by the community, the ownership rights should be clearly specified in the administrative records.
7. Market Based Approaches:
Besides regulator measures, there is urgent need for adopting market based approaches for the protection of environment. They aim at pointing to consumers and industries about the cost of using natural resources on environment. These costs are reflected in the prices paid for goods and services so that industries and ultimately the consumers are guided by them to reduce air and water pollution.
The Market Based Instruments (MBIs) are in the form of environmental taxes that include pollution charges (emission tax/pollution taxes), marketable permits, depositor fund system, input taxes/product charges, differential tax rates and user administrative charges and subsidies for pollution abatement equipment for air and water resources.
8. Regulatory Policies:
Regulatory polices also help in reducing environmental degradation. Regulators have to make decisions regarding prices, quantity and technology. In making decisions, they have to choose between the quantity or the price of pollution or resource use of technologies.
The regulating authority has also to decide whether policies should target the environmental problem directly or indirectly. It lays down technical standards and regulations and charges on air, water and land pollutants. Regulators should be impartial in applying environmental standards to both public and private sector polluters or resources users.
9. Economic Incentives:
Like regulatory policies, economic incentives relate to price, quantity and technology. Incentives are usually in the form of variable fees to resource users for the quantity of pollutants in air, water and land use. They are given rebates if less waste or pollution is generated than the emission standards laid down.
10. Public Participation:
Public awareness and participation are highly effective to improve environmental conditions. Conducting of formal and informal education programmes relating to environment management and environmental awareness programmes can go a long way in controlling environmental degradation and keeping the environment clean. For instance, the scheme of eco-labelling of products helps consumers to identify products that are environment friendly.
Public participation can also render costless and useful assistance in Afforestation, conservation of wildlife, management of parks, improvement of sanitation and drainage systems and flood control. Use of indigenous institutions, local voluntary organisations and NGOs can render much help in educating the masses about the harmful effects of environmental degradation and the benefits of keeping the environment clean.