Synonyms
More meanings
Tip: select a single word for meaning & synonyms.
Select multiple words normally to copy text.
Population and Environment: NBSE Class 11 Environment
Get notes, summary, questions and answers, MCQs, extras, and PDFs of Chapter 4 “Population and Environment” which is part of NBSE Class 11 Environment Education. However, the notes should only be treated as references and changes should be made according to the needs of the students.
If you notice any errors in the notes, please mention them in the comments
Summary
The chapter “Population and Environment” explores the relationship between population growth and environmental degradation. It begins by discussing the sharp increase in the world population since World War II, a phenomenon known as population explosion. This growth has led to significant strain on the Earth’s limited resources, including food, water, and energy. The chapter highlights that more people now survive due to better healthcare and food availability, but this also means a heavier burden on resources.
One of the major concerns is overcrowding, which occurs when the population exceeds the capacity of the Earth to support it comfortably. Overpopulation can lead to issues such as poverty, as the government may struggle to provide essential services like education, healthcare, and employment. The chapter discusses the debate on whether population growth causes poverty or poverty leads to population growth, suggesting that both are interlinked.
The chapter also explains how population size affects consumption patterns and technology use, which in turn impact the environment. For example, an increase in population leads to higher carbon dioxide emissions, contributing to global warming and climate change. The greenhouse effect, where carbon dioxide traps heat in the Earth’s atmosphere, is exacerbated by the growing number of people and their energy needs.
Deforestation is another critical issue discussed in the chapter. As more land is cleared for human settlements and agriculture, forests are rapidly disappearing, leading to the extinction of many plant and animal species. This loss of biodiversity poses a severe threat to the environment and human survival.
Textbook solutions
Multiple-Choice Questions
1. Clearance or removal of a forest where the land is later converted into a non-forest use is known as
A. Deforestation
B. Reforestation
C. Afforestation
D. Forestry
Answer: A. Deforestation
2. Which of the following wildlife species is near to extinction in Nagaland?
A. Dipterocarpus
B. Macrocarpus
C. Shore
D. All of these
Answer: D. All of these
3. Which of the following is an inexhaustible source of energy?
A. Coal
B. Fuel Oil
C. Sunlight
D. Natural Gas
Answer: C. Sunlight
4. Population explosion refers to
A. Explosion near a populated place
B. Enormous increase in population
C. Stress felt by people due to depletion of resources
D. Poaching of endangered animal population
Answer: B. Enormous increase in population
5. Which of the following is not a greenhouse gas?
A. Ozone
B. Carbon-dioxide
C. Oxygen
D. Water vapour
Answer: C. Oxygen
Short Answer Questions
1. Define population explosion.
Answer: Population explosion refers to the enormous increase in population.
2. What are the two concerns arising out of population growth?
Answer:
- Poverty: Population growth creates difficulties for the government in providing education, health, housing, and employment.
- Environmental Degradation: Population pressure leads to deforestation, loss of biodiversity, and increased greenhouse gas emissions.
3. How does poverty affect population growth?
Answer: Poverty affects population growth in a two-way process. Rapid growth of population creates difficulties for the government in providing education, health, housing, and employment to all those in need. On the other hand, failure by the government in providing social facilities and fair economic development can lead to conditions under which couples continue to have large families.
4. Define greenhouse effect?
Answer: Greenhouse effect is the process by which carbon dioxide in the atmosphere prevents the escape of outgoing long-wave radiation from the Earth to outer space, leading to an increase in the Earth’s temperature.
5. What would be the effects of global warming on the environment?
Answer: The effects of global warming on the environment include melting of polar icecaps, rising sea levels, changes in regional and global climates, alteration of natural vegetation, and impacts on crop production.
6. Differentiate between exhaustible and flow resources.
Answer:
- Exhaustible resources: The resources which are used up as they are exploited are known as exhaustible resources.
- Flow resources: The resources present in the environment, which can be used again and again, are known as flow or replaceable resources.
Long Answer Questions
1. Discuss how population growth has resulted in deforestation and species extinction.
Answer: Deforestation, especially the loss of tropical rainforests, has caused the destruction of wildlife and is a threat to the biodiversity of life on earth. Experts agree that population pressure contributes directly to the continuing loss of forest cover. Based on FAO land use estimates, it would appear that in the past three decades or so, 59% of the forests cleared in developing countries were for human settlements, roads, and other non-agricultural developments – almost entirely related to population growth. FAO data have also estimated that a further 20% of cover may have been lost because of clearance for farmland driven by population pressure, not counting new farmland needed to meet increased consumption of food and cash crops per person. In Nagaland, a number of wildlife species are near to extinction or endangered. Some of these plants are Dipterocarpus, Macrocarpus, Shorea, Rhododendron, Mesua, and many rare species of orchids are in danger. Among animals, elephant, sloth bear, tiger-civet, tiger, tailed pig, and Indian bison are in danger.
2. What is the stress on resources caused by increased population?
Answer: An increased population means a greater drain on the world’s limited resources. Timber is needed to provide decent housing. So are iron, copper, aluminium, and other metals. Vehicles to carry people and goods require tremendous amounts of metals. Some of these metals are already scarce. Population pressure upon resources differs from one part of the world to another. There is no unambiguous terminology for describing the relationship between population and resources, but the term “population/resources ratio” is often used – even if there is little agreement about how such a quotient should be measured. Measurement of population presents a few problems, but there are many rival interpretations for resources. Even the simple definition that they are substances which satisfy human needs makes their catalogue vary from culture to culture. Obviously, the range of resources increases with the aims, talents, and efforts of the population, but it must be kept in mind that the resources of a given area are not always exploited by its own people, but often by a foreign company or power, thus making simple analysis difficult. Furthermore, there are two types of resources:
Exhaustible resources: The resources which are used up as they are exploited are known as exhaustible resources.
Replaceable resources: The resources present in the environment which can be used again and again are known as flow or replaceable resources.
Think and Answer
1. Other than implementing family planning programmes, what steps can be taken to decrease environmental degradation due to population pressure?
Answer: The following steps can be taken to decrease environmental degradation due to population pressure:
- Promoting sustainable agricultural practices to increase food production without degrading the environment.
- Encouraging the use of renewable energy sources to reduce dependency on fossil fuels.
- Implementing afforestation and reforestation programmes to restore degraded lands.
- Enhancing water management practices to prevent water scarcity and pollution.
- Promoting education and awareness about the importance of environmental conservation.
- Encouraging urban planning that considers environmental impacts and reduces overcrowding.
- Supporting research and development in technologies that reduce environmental impact.
2. The climatic conditions of Nagaland are different from those of Punjab. Search about the crops and growing techniques suitable for Nagaland to improve the crop production.
Answer: In Nagaland, the following crops and growing techniques are suitable to improve crop production:
- Crops:
- Rice: The main crop, particularly the Jhum (shifting) cultivation variety.
- Maize: Grown during the Kharif season.
- Millets: Such as finger millet, which thrives in the hilly terrain.
- Pulses: Including pigeon pea and black gram.
- Horticultural crops: Fruits like oranges, pineapples, and bananas are suitable.
- Vegetables: Such as potatoes, tomatoes, and leafy greens.
- Growing Techniques:
- Jhum cultivation: Traditional slash-and-burn method, though efforts are being made to transition to more sustainable practices.
- Terrace farming: Helps in reducing soil erosion and retaining water in the hilly regions.
- Organic farming: Given the low use of chemical fertilizers, promoting organic farming is suitable.
- Integrated farming: Combining crop cultivation with livestock and fisheries to make optimal use of resources.
- Agroforestry: Growing trees and crops together to maintain soil fertility and provide additional income.
Extras MCQs
1. What has nearly doubled since World War II?
A. Earth’s population
B. Food production
C. Medical advancements
D. Urban areas
Answer: A. Earth’s population
Q. What term is used to describe the enormous increase in the number of people?
A. Population density
B. Population growth
C. Population explosion
D. Overcrowding
Answer: C. Population explosion
Q. How many people are predicted to join our planet’s population every year?
A. 60 million
B. 70 million
C. 80 million
D. 90 million
Answer: C. 80 million
Q. What do many countries promote to control population growth?
A. Migration programs
B. Food distribution
C. Family planning programs
D. Educational reforms
Answer: C. Family planning programs
Q. What is the foodgrain production of India in 2012-13?
A. 174.77 million tonnes
B. 196.81 million tonnes
C. 230.78 million tonnes
D. 255.36 million tonnes
Answer: D. 255.36 million tonnes
Q. What do some experts fear might be necessary to control population growth?
A. Economic sanctions
B. Laws limiting family size
C. Improved healthcare
D. Urban expansion
Answer: B. Laws limiting family size
Q. At what rate is a new desert being created around the Sahara in Africa?
A. 170 acres an hour
B. 420 acres an hour
C. 100 acres an hour
D. 250 acres an hour
Answer: B. 420 acres an hour
Q. Which organisation announced an Action Plan for Tropical Forests in 1985?
A. United Nations
B. World Bank
C. World Health Organization
D. Green Peace
Answer: B. World Bank
Q. How many species are estimated to face extinction each day due to deforestation and population growth?
A. 10-50
B. 50-100
C. 100-150
D. 150-200
Answer: B. 50-100
Q. What proportion of the world’s electricity is currently generated by water power?
A. One-third
B. One-fourth
C. Half
D. Two-thirds
Answer: A. One-third
11. Which resources are considered exhaustible?
A. Timber and iron
B. Coal and oil
C. Copper and aluminium
D. Water and sunlight
Answer: B. Coal and oil
Extra Questions and Answers
1. What are the reasons for the Earth’s population nearly doubling since World War II?
Answer: More and better food and medical care have kept alive many people who would otherwise have died, contributing to the Earth’s population nearly doubling since World War II.
Q. What term is used to describe the enormous increase in the number of people?
Answer: The enormous increase in the number of people is called population explosion.
Q. What does a doubled population mean for the world’s resources?
Answer: A doubled population means a greater drain on the world’s limited resources.
Q. What is population pressure?
Answer: Population pressure is the strain imposed on natural resources by human overpopulation.
Q. How many people join the Earth’s population every year, according to recent predictions?
Answer: According to recent predictions, over 80 million people join our planet’s population every year.
Q. Why can environmental conditions deteriorate even as the growth of population slows down?
Answer: Environmental conditions can deteriorate even as the growth of population slows down because population variables interact with consumption patterns, technologies, and political and economic structures, influencing environmental change.
Q. What is the foodgrain productivity in Nagaland compared to Punjab?
Answer: The foodgrain productivity in Nagaland is presently assessed at only 11.54 kg per capita per month, while it is 79.19 kg per capita per month in Punjab.
Q. What concerns do biologists have regarding overcrowding?
Answer: Biologists are increasingly concerned with many troubles that arise from overcrowding and feel that the population should not grow beyond the capacity of the Earth to house people in basic comfort.
Q. How does population multiply the use of resources and space?
Answer: One theory states that whatever the levels of consumption, involving whatever technology, population will multiply the use of resources and space as well as the output of waste, other things being equal. This theory also stresses the impact on the environment of population growth in affluent societies.
Q. What role does population play in the increase in carbon dioxide emissions?
Answer: Population appears to be a vital factor in the increase in carbon dioxide emissions. According to an estimate, over a third of the doubling of fossil fuel emissions in developed countries between 1960 and 1988 was due to increased population, and nearly half of the tripling of CO₂ emissions in developing countries was due to the same cause.
Q. What potential effects does global warming have on the environment?
Answer: A significant global warming of the atmosphere would have profound environmental effects. It would hasten the melting of the polar icecaps, raise sea levels, change the climate regionally and globally, alter natural vegetation, and affect crop production. These changes would, in turn, have an enormous impact on human civilisation.
Q. How does population pressure contribute to deforestation?
Answer: Experts agree that population pressure contributes directly to the continuing loss of forest cover. Based on FAO land use estimates, it would appear that in the past three decades or so, 59% of the forests cleared in developing countries were for human settlements, roads, and other non-agricultural developments, almost entirely related to population growth.
Q. What is happening to wildlife species in Nagaland?
Answer: In Nagaland, a number of wildlife species are near to extinction or endangered. Some of these plants are dipterocarpus, macrocarpus, shore, rhododendron, mesua, and many rare species of orchids are in danger. Among animals, the elephant, sloth bear, tiger-civet, tiger, tailed pig, and Indian bison are in danger.
Q. What is the current rate of extinction estimated to be?
Answer: The current extinction rate has been variously estimated between 50 and 100 species a day, with millions of species facing extinction in the present decade. Much of this is attributed to population growth.
Q. How is water use related to population growth?
Answer: Water use is closely related to population growth. About a decade ago, it was estimated that between 2.7 billion and 3.5 billion people could be living in water-stressed or water-scarce countries in 30 years’ time. Under the United Nations’ medium population projection for 2050, water scarcity is likely to affect nearly 10 billion people.
Q. What is meant by “population/resources ratio”?
Answer: “Population/resources ratio” is a term often used to describe the relationship between population and resources, though there is little agreement about how such a quotient should be measured. The terminology for describing this relationship is not unambiguous, and the resources of a given area are not always exploited by its own people but often by foreign companies or powers.
Q. What are exhaustible resources?
Answer: The resources which are used up as they are exploited are known as exhaustible resources.
Q. What are replaceable resources?
Answer: The resources present in the environment which can be used again and again are known as flow or replaceable resources.
Q. What is population explosion? Why is it considered a significant danger?
Answer: Population explosion refers to the enormous increase in the number of people, which many experts believe is the greatest danger facing mankind. This phenomenon results from more babies being born and more people being kept alive due to better food and medical care. A doubled population means a greater drain on the world’s limited resources, and the strain imposed on natural resources by human overpopulation is referred to as population pressure. According to recent predictions, over 80 million people join our planet’s population every year.
Q. How does population growth affect food security? What measures are suggested to address mass hunger?
Answer: Even today, more than half of the people in the world do not have enough to eat. Agricultural experts have developed new kinds of rice and wheat plants that yield higher crops per acre, which can help prevent hunger. However, ways still need to be found to obtain more protein-rich food from the sea or by growing other varieties like synthetic chemical foods. The distribution of food must be changed, with countries that have excessive food needing to make sacrifices to feed underfed countries to avoid mass hunger.
Q. How does population growth contribute to global warming and the greenhouse effect?
Answer: Population growth is a vital factor in the increase in carbon dioxide emissions, contributing significantly to global warming and the greenhouse effect. Over a third of the doubling of fossil fuel emissions in developed countries between 1960 and 1988 was due to increased population. In developing countries, nearly half of the tripling of CO₂ emissions was due to the same cause. As more heat is produced and less escapes due to carbon dioxide in the atmosphere, the Earth’s temperature increases, leading to global warming with profound environmental effects.
Q. What role does population pressure play in deforestation and species extinction?
Answer: Population pressure directly contributes to the continuing loss of forest cover. According to the UN Food and Agricultural Organisation (FAO), changes in local population density can predict deforestation. In the past three decades, 59% of the forests cleared in developing countries were for human settlements, roads, and other non-agricultural developments, almost entirely related to population growth. Additionally, population growth drives deforestation for farmland and increases the consumption of food and cash crops, leading to the loss of biodiversity and species extinction.
23. What are exhaustible and replaceable resources?
Answer: Exhaustible resources are those which are used up as they are exploited, such as coal, oil, and natural gas. In contrast, replaceable resources, also known as flow resources, can be used again and again, such as solar and wind energy. This distinction is vital when considering the future capacity of an area to support its population. The Conservation Movement has highlighted the irretrievable damage caused by humans to the environment and the need to conserve resources, emphasizing the importance of managing both exhaustible and replaceable resources sustainably.
