24 Impact of population growth on environment and society

Nupur Mahajan and Gautam Kshatriya

Contents:

    Stages of cultural development and population growth

Determinants of population structure

• Population size
• Population distribution
• Population composition
• Population consumption

Food production

Water resource management

Energy

Possible solutions for reducing population growth and environmental degradation

Summary

Learning objectives:

• To get an insight the stages of cultural development and population growth around the world.
• To understand the determinants of population structure and their effect on environment and society.
• To  come  up  with  possible  solutions  for  reduction  in  population  growth  and  subsequent environmental degradation.

    Stages of cultural development and population growth

Around 6 million years ago, primitive human predecessors or hominids emerge in the fossil record (Wood, 2002). The earliest remnants of a small, bipedal homininae, Sahelanthropus tchadensis have been found in Chad (Brunet et al., 2002). However, the first identifiable human fossil was of Homo habilis which evolved about 2.5 million years ago, around the time when the Pleistocene ice ages were just beginning in mid-latitudes. The oldest remains of this human fossil have been found in East Africa and in cave deposits of the Southern parts of Africa. Ever since then, the human population spread over the entire land surface of the Earth (Oppenheimer, 2003). Archaic Homo sapiens may have reached Asia by around 2 million years ago (Larick and Ciochon, 1996; Zhu et al., 2008) and Europe at almost the same time (Moncel, 2010). The stone tool culture of Italy and Spain in southern Europe has shown association with Homo, these tools date back to 1.3–1.7 Ma (Arzarello et al., 2007; Carbonell et al., 2008). In northwest Europe and Britain the earliest dates for human occupation have been noted to be around 0.78 Ma (Parfitt et al., 2010). Homo sapiens appeared in Africa around 160,000 years ago (Stringer, 2003; White et al., 2003) and then they spread out of Africa to different parts of the world. Some of these dates are controversial, and this is especially true in case of human migration to Australia where the range is 40,000 years to as much as 150,000 years (Kirkpatrick, 1994: 28–30), but 50,000 years ago has been widely accepted (Balme, 2011). There is also substantial ambiguity about the dates for human migrating and settling in parts of America (Goebel et al., 2008). Many argue that the premier colonizers of North America were equipped with Clovis spears and they arrived from Asia via the Bering land bridge around 12,000 years ago. The settlement of Oceania happened relatively late, with migration of the western archipelagos of Micronesia and eastern Melanesia occurring at 3500–2800 B.P, of central and eastern Micronesia at 2200–2000 BP, and of eastern and southern Polynesia at 1100–700 BP (Anderson, 2009).

It is difficult to make an estimate of the population size of the early stages of human development and migration. Before the advent of agricultural revolution around 10,000 years ago, human groups sustained by hunting and gathering of animals and wild produce of forests. It was possible to estimate the population size at that time as the groups used to live in bands which were spread in distinct areas.

The population density was low and an optimum territory area for a band of hunters and gatherers would range from 300-500 per km2 in the Middle Eastern woodland while in the drier regions it might have been 500–2000 km2 (Bar-Yosef, 1998). At that time the world population may have been estimated to be around 5 million people (Ehrlich et al., 1977: 182). Human population estimates for the Holocene period where a transition was observed from hunting gathering to Neolithic culture, are diverse and controversial (Boyle et al., 2011). However, the agricultural revolution probably facilitated the human population expansion to about 500 million by 1650 A.D. The human population reached about 1000 million by 1850 A.D., 2000 million by 1930 A.D. and 4000 million by 1974 A.D. after the advent of the medical and industrial revolution and subsequent developments in agricultural practices and colonization of newer areas. The human population has reached over 6000 million by the year 2000 and in 2012; it crossed the 7000 million mark. Improvement in the field of medicine and introduction of vaccines for controlling malaria, cholera and eradication of smallpox has been responsible for striking decrease in death rates throughout the world, however, decrease in death rates could be achieved, but the measures for birth control were not being implemented efficiently. For this reason, the annual population growth rate in the 1990s in South Asia was 2.64%, Africa-2.66% and Latin America was the region where population increased by six fold between the year 1850 and 1950. In the period from 2005–2010 the population growth rates slowed down considerably. The worldwide annual growth in population has been around 75-77 million people over the last decade. The part of the human impact, however, has not been an easy process of rising change in reaction to linear population growth which has been noticed over time. For instance, at specific places in specific times there have been bouts of reverse population growth and ecological change as cultures have distorted, wars happened, disease spread and habitats were abandoned. To explain this phenomenon of reversal in population growth, Denevan (1992) has indicated towards the decline of Native American populations in the new world after the entry of Europeans into America. This created, which was probably regarded as ‘the greatest demographic disaster ever’. The total population of the western hemisphere in 1750 was maybe less than one third of what it might have been in 1492, and the ecological consequences were present in a large number. Evidently, this development of the human inhabitants on the Earth is in itself possible to be a highly important reason for the transformation of nature. However, rise and development of culture and technology has been of no lesser importance for population growth.

Man’s unique power to manoeuvre things and build up on experiences has enabled him to overcome the barriers of temperature, aridity, space, seas and mountains that have always proven to be a limiting factor in case of other species to particular habitats within a restricted range. Humans were able to perform functions which the other organisms could not do with the help of devices like fire, clothing, shelter, tools etc. and these devices facilitate them to change the original formation of any material in to a significant object for their benefit.

Cultural change was substituted for biological evolution for the very first time as a way of adapting an organism to its new habitats in a wide range which ultimately resulted in the inclusion of the whole earth. The growing impact of humans on the environment has been frequently expressed in terms of the following equation:

I = P A T {where I is the impact humans apply on the environment, P is the number of people, A is the affluence (or the demand on resources per person), and T is a technological factor (the power that humans can exert through technological change)}.

The variables P, A and T in the expression have been seen by many as ‘the three horsemen of the environmental apocalypse’ (Meyer, 1996). This equation may hold true in various situations, but Meyer pointed out that the formula could not be applied in the mechanistic ways.

Therefore, the ‘cornucopia view’ looks at the population as the ultimate resource which has the much needed talent to change things for better rather than the ultimate depleter of environment. There are instances where a sturdy population growth has possibly led to a decrease in environmental degradation (Tiffen et al., 1994). Similarly a debate on the effect of poverty and affluence on environmental degradation is also currently coming up.

On one hand many poor countries have severe environmental issues and these countries do not have the required resources to deal with these problems, where as affluent countries do. On the other hand, affluent countries have taken resources from the poverty struck countries and using them injudiciously and thus, leading to depletion of these resources on a faster pace.

Technology can be either a factor leading to improvement or damage. For example: the use of technology such as chlorofluorocarbons has led to ozone depletion and causing damage to the environment while using technology to set up renewable energy source for production of electricity instead of burning fuels at power stations for the same purpose proves to be beneficial for the environment.

In addition to population, affluence and technology, environmental changes are also dependant on the organization of different societies, their social and economic structure. Thus, the controls of environmental changes due to human impact are complex and in many cases controversial, but all of these factors play some sort of role at some place or time to some extent.

Human beings are remarkable creatures and this can be proven by the fact of human expansion which started from emergence of small population groups in Africa and then evolving and migrating to almost each and every corner of Earth. The current annual human population is about 7.5 billion people which means there are more than seven billion five hundred million bodies which are to be fed, clothed, nurtured and educated. More than 7.5 billion individuals who are consuming the resources are also responsible for producing vast quantities of waste. According to the estimates of the United Nations, the world population will be beyond 9.2 billion by 2050.

Before the improvements in nutrition, medical and technology, the human population was growing very slowly and was in constant check by the limiting factors such as disease, climate fluctuations, etc. The population growth data indicates that it took 1804 years for humans to reach a population of 1 billion. However, with the improvisation in the field of nutrition, medicine and technology, the population increase became rapid.

Figure 1: Human population witnessed an exponential growth over the past few hundred years.

(Source: https://ourworldindata.org/life-expectancy/)

The impact of human population growth on environment has taken two major forms:

• Consumption of resources such as land, food, water, air, fossil fuels and minerals
• Generation of waste products as a result of consumption of resources such as air and water pollutants, toxic materials and greenhouse gases.

   It is matter of concern and worry that unchecked population growth may result in an environmental catastrophe. Circumstantial evidence undoubtedly indicated that as human population is increasing, the environment is degrading. Due to the huge impact of human population on the planet, the scientists have coined a new term to define this time period, they have referring to this as the ‘Anthropocene Epoch’. The previously named geological epochs were defined on the basis of the geological and climatic processes which influenced that time period, likewise, as proposed the Anthropocene Epoch is influence by the humans and their activities which have been moulding the environment according to their convenience. Therefore, humans have been now regarded as the novel global geophysical force.

Population growth is determined by various factors which interplay with each other. The factors include:

• Population distribution which included the density, migration patterns and urbanization
• Population composition which is attributed by age, sex and income levels
• Population consumption patterns which is the most important factor, and consists of the consumption of resources by the population.

    Population size

As the world population continues to grow on a rapid pace, the essential resources such as drinking water, fertile land, forests, fisheries etc are becoming limited. Therefore, more people will use more resources which will lead to crunch in the availability of resources and more waste generation.

The discussion on population size is incomplete without the concept of ‘carrying capacity’ which is defined as the maximum number of people who can be sustained by the environment for indefinite time.

The actual human carrying capacity of the earth is still debatable. The estimated ranges have reached high figures and have shifted from 500 million people to more than one trillion. The scientists do not agree on the figures of carrying capacity of the earth and also do not approve of the methods used for determining these numbers. They have found huge variability during estimation of the carrying capacity, hence, the best and the most accurate way of calculation has yet not been given.

The consumption of resources by the people around the world is also not even and very distinctive. For instance: An average middle class American may consume about 3.3 times the amount of food actually required for survival and almost 250 times the quantity of water necessary for living. So if all the people on earth start to consume resources at the rate as an average middle class American, there will be enough resources only for the population of 2 billion people. However, if the resource consumption is judicious and people only consume the amount which is required by them, the carrying capacity of Earth will be much higher.

Population distribution

The pattern of distribution of population across the Earth also has an impact on the environment. Due to poverty, unawareness and inaccessibility regarding the methods of family planning, the birth rates are higher in developing countries whereas developed countries have a lesser burden of birth rates, as the facilities and income leads to lower birth rates. Figures have indicated that 80% of the world’s population has been living in under developed and developing nations and this has been adding a pressure on the local environment.

Every country is now-a-days witnessing an increasing trend of urbanization where majority of its inhabitants are becoming urbanized. This has been indicated by the fact that in the year 1960, less than one third of the total population of the world lived in cities, this estimate reached 54% by the end of the year 2014. Owing to this trend, it has been projected that by 2050, about 66% of the world’s population will be living in cities.

Many researchers argue that urbanization has led to efficient use of resources, there have been environmental issues related to such mass movement of people from under developed to urbanized centres in search for better education and jobs. This mass migration has led to establishment of slums in the cities which has led to indoor pollution, because these types of settlements do not follow any environmental regulations, are clustered and crowded, have poor sanitation and are prone to growth of infectious and other chronic diseases. The developed nations have also been a witness to higher influx of people to the cities than before. Due to the rise in population, there is a pressure on the cities and the resources available there. Resources such as water, food, air, energy are now getting depleted by the pollution caused by the growing number of cars, use of heaters, air conditioners, setting of factories which dispose there wastes and smoke into water bodies and air, this is causing an array of environmental issues at the local level.

Human beings have a nomadic lifestyle; they have always explored the Earth by moving across it. Although, these migrations are aggravated by the conflicts such as wars, or environmental crisis at that place, the movement of people from one place to another often leads to short or long term amendments in the environment. For example: due to the war crisis in the Middle East countries such as Syria and Iraq, the people are migrating from these war hit places into refugee camps and other countries. This kind of population migration or transfer is being termed as unplanned migration which has resulted in several million people fleeing these counties and becoming refugees. The establishment of refugee camps to accommodate a large population of refugees require large area of land, proper water supply, sanitation etc. however, these refugee camps are not well equipped with these facilities and as a result lead to damaging of land, hampering of water supplies, lack of sewerage systems which are a cause of pollution and environmental degradation.

Population composition

The composition of a population may also influence the surrounding environment. Currently, the world population has both the major proportion of youth (aged less than 24) and the highest percentage of elderly people. Younger people may migrate to other places for better facilities and opportunities; this may intensify the environmental concerns in urban areas.

Life expectancy has improved by about 20 years since the year 1960 because of accessibility to better medical facilities. While this can be regarded as one of the biggest victory of mankind, and by an individual’s point of view it is a good thing, if we understand this from the point of view of Earth, it is addition of some more bodies which will consume more resources and will produce more waste for around 20 more years that the past.

Ageing populations are another constituent to the varied implications of demographic population alteration, and pose challenges of their own. For instance: between 1970 and 2006, proportion of people in Japan over 65 years of age grew from 7 per cent to over 20 per cent of its population. This has huge affect on the workforce and the government agencies that are responsible for spending on the pensions and health care facilities of elderly population in the country.

Population income is also a significant aspect. The uneven division of earnings results in stress on the environment from the population under lower and the higher income levels. In order to survive, poor people contribute adversely in unsustainable levels of resource use such as burning tyres or plastics for fuel which causes pollution. The need to feed themselves and their families, they may end up using the scarce natural resources like the forest produce and animals. On the other hand, the higher income individuals consume large levels of resources injudiciously by the lifestyle and luxuries they opt for.

On a nationwide level, economic growth and environmental damage are also interrelated. The least developed nations have lower levels of industrial activity which result in lesser environmental damage. The developed countries have initiated ways for improvising on technology and energy efficiency for the reduction of their environmental impact while retaining higher levels of production. The locations of most environmental damage are the developing countries because they experience extreme resource consumption and are burdened by the demand of developed countries for production. To fulfil the demands of production, these countries experience migration of humans for work, which leads to higher resource consumption and as a result the waste production also increases.

Population consumption

People residing in developed countries generally have a bigger ecological footprint than the ones staying in developing countries. The ecological footprint is a standardised measure to estimate how much productive land and water is required to produce resources that are consumed, and to absorb the wastes produced by a person or group of people. Although poverty and environmental depletion are closely related, it is the indefensible patterns of consumption and waste production especially in developed nations which are of a greater worry.

Human population living in poor countries are already stressed by food insecurity; poor sanitation, housing and water supplies; and the incapability of meeting the basic necessities of the current population. A fairly large fraction of these populations are surviving on subsistence agriculture. As the population experiences growth, the competition for productive land and exploitation of limited resources will increase. The people who live in these countries are heading toward improvised and higher standard of living which matches the lifestyles of the developed countries where the existing pattern of consumption and resource utilization is not essentially sustainable.

Food Production

Meeting the escalating food demand is certainly the most fundamental challenge and the most prominent population and environmental catastrophe. With the development of efficient farming techniques and introduction of fertilizers, pesticides; the crop yields per unit area has improved and the quantity of land under cultivation has also expanded. The global food production is at par with population growth. Yet millions of people still do not have enough quantity of food to eat. Food insecurity is time and again a consequence of the unavailability of food, inadequate purchasing power, inappropriate division, or insufficient usage of food at household level. Poverty, natural disasters, political violence, and other geopolitical factors create an inconsistent distribution of food across the world. 

The profits in food production are a result of higher yields in fertile agricultural lands and novel cultivation of subsidiary lands which has been possible through industrial agriculture. Nevertheless, improper use of machines, chemicals, and extensive irrigation, is resulting in depletion of quality as well as quantity of land and water resources. Land is beco ming prone to wind and water erosion. Improper irrigation practices lead to increase of salinity in soil and a larger requirement of irreplaceable groundwater. Chemical runoffs which are constituents of fertilizers and pesticides also degrade water resources.

Traditional agriculture or non-industrial farming is continuing to strengthen in less developed nations. This type of cultivation activities frequently involve cultivation of brittle soils that are hard to cultivate, like dry lands, highlands, and forests. Expansion of farmlands towards fragile lands in an area can lead to soil erosion, deforestations and desertification of the land.

Water Resource Management

Population growth and distribution have been correlated to accessibility of freshwater and sustainability of renewable sources of water. The demand for water has increased essentially over the last five decades because of population growth and also since there has been a growth in the usage of water for household, cultivation, and industrial purposes. Suitable management of water resources is very important for keeping up with the needs of an ever increasing population and for escalating water uses. Simultaneously, we must also take measures to prevent the degradation of water and try to clean up polluted water sources.

A significant number of the global population do not have access to a proper supply of safe and clean water for household purpose. In some under developed countries, only half of its population have access to safe drinking water, while the other half is still deprived of the basic necessity. Shortage of water and polluted water resources often lead to food insecurity. Consumption of polluted water also causes major health problems.

Since water just flows in the form of rivers, seas and oceans, it is oblivious of the national boundaries and may flow through them, the use of water upstream, contamination, and abridged flows will have an effect on the countries which are situated at the downstream. The future of water resources is highly dependable on improvising upon the management policies and practices related to water resources at a global level. Organization and institutions which undertake the responsibility of water management must integrate proficient techniques for utilization of water for industrial and agricultural use. These management policies must consider the security of the local community in association with national governments in order to safeguard water rights and guarantee the success of programs.

Energy

Human activities such as the burning of fossil fuels, cutting of forests and clearing of forest cover for expansion and establishment of urban centres, have led to a considerable increase in the emissions of carbon dioxide. CO2 emission is a major contributor to climate change which is most likely to cause rise in temperatures, lead to more intense weather patterns, aid the spread of infectious diseases, and exert more pressure on the environment.

The United States is the prime contributor of overall carbon dioxide emissions and it also among the countries with highest per capita rates. According to the World Resource Institute, the U.S. per capita CO2 emission rates have increased from 19.2 metric tons per person to 19.9 metric tons between the year 1990 and 2002. Per capita usage has also experienced a rise in China, from being 2.2 to 2.9 metric tons between 1990 and 2002. China surpassed the United States in total carbon dioxide emissions in the year 2010 and currently it is the prime contributor of overall CO 2 emission in the world.

Burning of fossil fuels contribute to the enormous majority of energy production. The growing use of fossil fuels is having an ill effect on the environment and degrading air and water. Air pollution from greater usage of coal and vehicular exhaust has caused acid rain which is responsible for damaging forests, lakes, and streams. Increasing fossil fuel utilization is leading to a significantly higher build-up of carbon dioxide in the atmosphere, more greenhouse gas emissions, which are consequently resulting in global warming.

Since the usage of fossil fuels as energy resources have such an adverse affect on the environment, efforts are being made to decrease the level of their usage. Renewable resources such as water and sunlight are being used to produce energy. This is being fulfilled by converting the energy stored in these resources with the help of hydropower plants and solar power plants. These alternative energy sources are more efficient and do not have harmful effects on environment, therefore, reducing the environmental costs from energy consumption. These methods ensure adequate supply of energy for the existing and future generations.

Not all humans are responsible for environmental degradation. The depletion of environment depends mainly on the consumption patterns and use of resources, which may be high in some countries and low in the other countries. In some countries, the people may consume resources wastefully while in some places there may not be enough resources to fulfil the basic requirements of the population.

Possible solutions for reducing population growth and environmental degradation

There have been theories which believe that if humans will not find ways to limit the population and burden on earth, the planet itself will find ways of doing that. Population growth is a serious issue which cannot be ignored, but it is ironical that the United Nations which is an eminent global organization has conducted only three world conferences under the domain of population and development. However, the government agencies across the globe have started to recognise the seriousness and significance of the situation, and are taking measures to reduce the environmental impacts of growing populations and consumption. The United Nations Climate Change Conference in Paris was conducted in December 2015 is one example; however, to organize such a meet, all the international organizations and their policies should be backed up and equipped with practical solutions at the individual, local, regional and national level.

Control of Population Growth

The rate of population growth should be reduced through implementation of effective family planning measures. This is important since the proportion of overall population in the working/labour force will grow further in the coming years as a result of alterations in the age structure of population.

Economic Development:

The objective of population control is not merely bringing a decline in the rate of fertility but it is also responsible for improving the quality of life of people. This is achieved through a rapid economic expansion. Therefore, an efficient family planning policy must be put together with a process to speed up economic development.

The developing countries which are currently in the phase of demographic transition can attain economic growth and advancement in the quality of life by commercialization of agricultural practices, industrialization, urbanization and growing advances in infrastructure which is increasing the chances of employment which is resulting in rise in income levels. These advancements will facilitate the country in achieving the much needed economic shift from low economic growth to high income growth. Consequently, this will raise the quality of life of the people and the population will automatically come under control.

Improving Health and Nutrition:

The food security for the weaker sections of the society in developing countries should be considered as a right along with their right to work, health, education and information. The government agencies have designed policies for agriculture, health, nutrition, maternal and child health care for the people of such countries.

It should be kept in mind that guarantee of good nutrition and absence of hunger is two very distinct issues. The prime effort should be done to remove hunger of the poor and then the long-term focus should be to provide nutrition to all the people so that it helps in the development of their overall well-being.

Improvement of health and proper nutrition levels are very significant factors which contribute to the social development of developing countries. To achieve this, the people under weaker sections of the society who do not utilize the adequate benefit of health, family welfare and nutrition services, must be made aware of such facilities to improve their status of health and nutrition.

Public Participation:

Public awareness and participation are highly successful for improvising environmental conditions. Education and environmental awareness programmes educating the masses have a very efficient successful rate in controlling environmental degradation. For examples: now-a-days, the electronic appliances come with labels which give the information regarding their levels of being eco-friendly, these measures can help the customers to select the product which will not harm them and the nature.

Public participation can also turn into costless and a useful support in afforestation, conservation of wildlife, maintenance of parks, improvement of sanitation and drainage systems and in flood control. Use of indigenous institutions, local voluntary organizations and NGOs can turn out to be of help in educating the masses about the harmful consequences of environmental degradation.

Summary

It is evident from this write-up that man’s unique power to manoeuvre things and build up on experiences has enabled him to overcome the barriers of temperature, aridity, space, seas and mountains that have always proven to be a limiting factor in case of other species to particular habitats within a restricted range. Human beings were able to perform functions which the other organisms could not do with the help of devices like fire, clothing, shelter, tools etc. and these devices facilitate them to change the original formation of any material in to a significant object for their benefit. This was the prime reason why human beings were able to spread to the entire globe with time and have been able to sustain for more than 1,50,000 years now and are increasing in number with each passing day. However, population growth has had its own impact on environment which led to deterioration in the quality as well as quantity of resources available on earth. Over population was featured with uneven distribution of resources, over-consumption and other population dynamics. Researchers have highlighted ways in which population variables such as age, sex composition, household composition, fertility, mortality, morbidity, etc. have had useful as well as harmful effects on the environment. The local institutions, non-government organizations, international bodies of environmental policy makers have been taking steps to monitor the distribution of resources to the population all over the globe, however, small yet significant measures are to be taken by the people so that there is enough to meet the needs of the present generation while keeping in mind the requirements of the future generations as well.

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    Suggested Readings

• Ahlburg, D. A., Kelley, A. C., & Mason, K. O. (Eds.). (2013). The impact of population growth on well-being in developing countries. Springer Science & Business Media.
• Goudie, A. S. (2013). The human impact on the natural environment: past, present, and future. John Wiley & Sons.
• Ramphal, S. S., & Sinding, S. W. (1996). Population growth and environmental issues. Greenwood Publishing Group.