Environmental Science Notes [For Dibrugarh University 2nd SEM NEP 2023]


For Dibrugarh University 2nd SEM NEP 2023


1.1 Nature, Scope and importance of environmental Science.

1.2 Climate change, causes, societal impacts, adaptation

1.3 Sustainable development and living


Meaning of Environment

The word environment is derived from the French word “environ” meaning surroundings. Hence, everything surrounding us is called environment. Every living beings is surrounded by materials and forces such as social, economical, biological, physical or chemical factors that constitute its environment. Environment is the sum of all social, economical, biological, physical or chemical factors which constitute the surroundings of man, who is both the creator and moulder of his environment.

Components/Segments of Environment

Environment has been classified into four major components:

1. Hydrosphere,

2. Lithosphere,

3. Atmosphere,

4. Biosphere.

Hydrosphere includes all water bodies such as lakes, ponds, rivers, streams and ocean etc. Hydrosphere functions in a cyclic nature, which is termed as hydrological cycle or water cycle. Lithosphere means the mantle of rocks constituting the earth’s crust. The earth is a cold spherical solid planet of the solar system, which spins in its axis and revolves around the sun at a certain constant distance.

Lithosphere mainly, contains soil, earth rocks, mountain etc. Lithosphere is divided into three layers-crusts, mantle and core (outer and inner). Atmosphere The cover of the air, that envelope the earth is known as the atmosphere.

Atmosphere is a thin layer which contains gases like oxygen, carbon dioxide etc. and which protects the solid earth and human beings from the harmful radiations of the sun. There are five concentric layers within the atmosphere, which can be differentiated on the basis of temperature and each layer has its own characteristics. These include the troposphere, the stratosphere, the mesosphere, the thermosphere and the exosphere.

Biosphere it is otherwise known as the life layer, it refers to all organisms on the earth’s surface and their interaction with water and air. It consists of plants, animals and micro-organisms, ranging from the tiniest microscopic organism to the largest whales in the sea. Biology is concerned with how millions of species of animals, plants and other organisms grow, feed, move, reproduce and evolve over long periods of time in different environments. Its subject matter is useful to other sciences and professions that deal with life, such as agriculture, forestry and medicine. The richness of biosphere depends upon a number of factors like rainfall, temperature, geographical reference etc. Apart from the physical environmental factors, the man made environment includes human groups, the material infrastructures built by man, the production relationships and institutional systems that he has
devised. The social environment shows the way in which human societies have organized themselves and how they function in order to satisfy their needs.

Need and Importance of Environmental Education

It can be said that environmental education is education through environment, about environment and for the environment. Environmental education is the educational process dealing with man’s relationship with his natural and man-made surroundings and includes the relation of population, pollution, resource allocation and depletion, conservation, transportation technology and urban and rural planning to the total human environment. Environmental education is the process of recognizing values and clarifying concepts in order to develop
skills and attitudes necessary to understand and appreciate the interrelatedness among man, his culture and his biophysical surroundings. The objectives and the guiding principles for environmental education are:

a) Awareness and sensitivity to the environmental and environmental challenges.

b) Knowledge and understanding of the environment and environmental challenges.

c) Attitude of concern for the environment and motivation to improve or maintain environmental quality.

d) Skills to identify and help resolve environmental challenges.

e) Participation in activities that lead to the resolution of environmental challenges.

Need of Public environmental awareness

The world today is confronted with the great problem of environmental degradation and pollution.

Different types of pollution, fast depleting forest resources, rapid population explosion, expanding industrialization, unplanned urbanization, mining, soil erosion etc. have created ecological imbalances in recent years.

Man’s quest for economic development has been mainly responsible for the ruthless exploitation of natural resources. Moreover, highly materialistic, greedy and luxurious life style attitude of human race indiscriminately exploited or imprudently destroyed the natural resources. All these activities have become a threat to the very existence of a number of living organisms. So creation of public awareness is must to protect the environment from further deterioration.

Scope of Environmental studies

Because of environmental studies has been seen to be multidisciplinary in nature so it is considered to be a subject with great scope. Environment is not limited to issues of sanitation and health but it is now concerned with pollution control, biodiversity conservation, waste management and conservation of natural resources. This requires expert eyes and hence is creating new job opportunities. The opportunities in this field are immense not only for scientists but also for engineers, biologists. There is a good chance of opportunity to find a job in this field as environmental journalists. Environmental science can be applied in the following spheres:

1. Ecosystem Structure and Function: The study of ecosystems mainly consists of the study of the processes that link the leaving organism or in other words biotic component to the non-living organism or a biotic component. So for the study of environment we should aware with biotic and abiotic components.

2. Natural Resource Conservation: For managing and maintenance of forests which are natural resources and for the maintenance of wildlife forms task under natural resource conservation. It is also a scope of environmental studies

3. Environmental Pollution Control: With the knowledge of environmental science everybody can control the pollution. He/she can handle the waste management and also look for ways to control pollution on the aspect of pollution control.

4. Environmental management: There are several independent environmental consultants who are working with Central and State pollution control Board. They offer advice to solve the problems of environment the optimum solution for the upcoming problems. They give direction for controlling pollution due to industrial development.

5. The scope of environmental studies in industry: Environmental scientists work towards maintenance of ecological balance, they also work towards conservation of biodiversity and regulation of natural resources as well as on preservation of natural resources. Most of the industries have a separate environmental research and development section. These sections govern the impact that their industry has on the environment.

6. Research and development: Research and development have tremendous scope due to increment in public awareness regarding the environment. Various universities and governmental organizations offer a scope for such research. These universities conduct research studies in order to develop the methods toward monitoring and controlling the source of environmental pollution. Due to an increasing threat from global warming, many steps are being undertaken for the reduction of greenhouse gases and the adoption of renewable energy resources.

7. Social Development: NGO (Nongovernmental organizations) help in creating awareness regarding the protection of the environment and making the masses aware of various environmental issues. They also generate a public opinion in this field.

Why Environment is Multidisciplinary in Nature

Subjects like botany, zoology, biotechnology, bioengineering, microbiology, genetics, biochemistry etc. helps in understanding biotic components and their interactions.

The basic knowledge of physics, chemistry mathematics, statistics help in understanding the different phenomena in the environment. Computer science and information technology is a part and parcel of environmental education.

Similarly, for control of pollution, environmental engineering is essential. Other branches of engineering e.g. chemical, civil, mechanical including new innovative technologies have been involved in protecting the environment.

Green chemistry finds its distinct and well specific role in protecting the degraded environment. Subjects like sociology, economics, education, philosophy are involved in a number of ways.

Environmental laws are always enacted for the protection of the environment. So environmental education carries the multidisciplinary nature where different aspects are dealt with holistic approach.

Also Read: Environmental Science Chapterwise Notes for 2nd SEM NEP 2023

– Unit 1: Environmental Science Notes

– Unit 2: Environmental Degradation Notes


Climate change

Climate change is a change in the global or regional climate patterns. It is caused by factors such as biotic processes, variations in solar radiation received by the earth, platonic and volcanic eruptions. Certain human activities have also been identified as significant causes of climate change often referred to as ‘Global Warming’. According to Intergovernmental Panel on Climate Change(IPCC) Fourth Assessment, climate change will create more stress on thesustainable development capabilities of countries like India. IPCC studies shows that in near future, the global mean surface temperature will rise by 1.4° to 3.8°C. Warming will be greatest over land areas and at high latitudes. The projected rate of warming is greater that has occurred in last 10,000 years.

Causes of climate change:

a) Burning of fossil fuels such as coal, oil, and gas

b) Deforestation and land-use changes

c) Agriculture and livestock production

d) Industrial processes and transportation

Impacts of climate change:

a) Rising global temperatures, which can cause heatwaves, droughts, and wildfires

b) Sea-level rise, which can lead to coastal flooding and erosion

c) Changes in precipitation patterns, leading to floods or water scarcity

d) Increased frequency and intensity of extreme weather events such as hurricanes, cyclones, and typhoons

e) Impacts on human health, including increased spread of disease and malnutrition

f) Impacts on ecosystems and biodiversity, leading to species extinction and habitat loss.

Climate change mitigation and adaptation measures:

a) Renewable energy: Promoting the use of clean and renewable energy sources like wind, solar, hydro, and geothermal energy to reduce greenhouse gas emissions.

b) Energy efficiency: Encouraging energy-efficient practices and technologies to reduce energy consumption and promote sustainable use of resources.

c) Forest conservation and afforestation: Protecting and expanding forest cover to enhance carbon sequestration and mitigate the impacts of climate change.

d) Sustainable agriculture: Promoting sustainable farming practices, such as conservation agriculture, agroforestry, and crop diversification, to reduce emissions from agriculture and enhance food security.

e) Water conservation and management: Encouraging water conservation and management practices to address water scarcity and reduce water-related impacts of climate change.

f) Disaster risk reduction: Developing strategies and measures to mitigate and manage the impacts of climate-related disasters, such as floods, droughts, and storms.

g) Infrastructure development: Developing climate-resilient infrastructure that can withstand the impacts of climate change, such as sea-level rise, flooding, and extreme weather events.

International agreements on climate change:

The Paris Agreement is an international agreement on climate change, signed in 2015 by 196 countries. Its goal is to limit global warming to well below 2 degrees Celsius above pre-industrial levels and pursue efforts to limit the temperature increase to 1.5 degrees Celsius. Countries are required to submit their own Nationally Determined Contributions (NDCs) outlining their emissions reduction targets and plans for achieving them.

Global Warming

Global warming means increase in the average temperature of the Earth’s near-surface air and the oceans. Climate change results from the global warming and caused in turn the presence and accumulation of greenhouse gases in the atmosphere. The gases like carbon dioxide (CO2) and methane (CH 4), are released into the air by the burning of fossil fuels such as coal, oil and gas as well as biomass. The emission of these greenhouse gases is a main reason for global warming. Global warming is also caused by land use change, for example in the burning of forests that reduces forest cover and leads to deforestation. The IPCC warned that by the end of the 21stcentury, it is possible that the earth’s temperature would rise by 2.40 to 6.40 degree celcius.

Causes and effects of global warming:

1. The primary cause of global warming is the increase in greenhouse gas emissions, primarily carbon dioxide, methane, and nitrous oxide, from human activities such as burning fossil fuels, deforestation, and agricultural practices.

2. The effects of global warming include rising sea levels, melting glaciers and ice caps, more frequent and severe weather events, and changes in precipitation patterns. These effects can have significant impacts on the environment and human health.

Greenhouse gases and their sources:

Greenhouse gases are gases that trap heat in the Earth’s atmosphere and contribute to the greenhouse effect.

The major greenhouse gases include carbon dioxide (CO2), methane (CH4), nitrous oxide (N2O), and fluorinated gases. CO2 is mainly produced by burning fossil fuels, deforestation, and cement production. CH4 is produced by livestock and rice cultivation, while N2O is produced by agricultural practices and industrial processes.

The increase in greenhouse gas concentrations in the atmosphere is a major cause of global warming and climate change.

Impacts of global warming on the environment and human health:

Global warming can lead to various impacts, including more frequent and severe heatwaves, droughts, and wildfires, changes in precipitation patterns, rising sea levels, and more frequent and severe storms and floods.

These impacts can have adverse effects on human health, such as increased respiratory and cardiovascular illnesses, as well as impacts on ecosystems, including the loss of biodiversity and the disruption of food chains.

Mitigation and adaptation strategies to address global warming:

a) Mitigation strategies aim to reduce greenhouse gas emissions by promoting renewable energy sources, improving energy efficiency, and promoting sustainable land use practices.

b) Adaptation strategies aim to reduce the vulnerability of communities and ecosystems to the impacts of global warming by promoting resilient infrastructure, implementing disaster risk reduction measures, and improving water management practices.

Meaning of Unsustainable and Sustainable development

Unsustainable development is characterized by an emphasis on economic growth at the expense of environmental protection and social well-being. It results in the depletion of natural resources, pollution, and other negative impacts on society that can have long-term consequences.

Sustainable development, on the other hand, aims to promote economic growth that is compatible with environmental protection and social well-being. It seeks to balance economic, social, and environmental considerations to ensure that development meets the needs of present and future generations.

why the shift from unsustainable development to sustainable development is necessary?

1. Environmental concerns: Unsustainable development harms the environment, whereas sustainable development promotes environmental protection and conservation.

2. Economic stability: Unsustainable development can lead to economic instability, whereas sustainable development promotes responsible resource management and investment in sustainable practices and technologies.

3. Social well-being: Unsustainable development can lead to social inequality, whereas sustainable development aims to promote social equality and improve quality of life for all.

4. Global challenges: Unsustainable development exacerbates global challenges, whereas sustainable development seeks to address these challenges by promoting responsible resource use, reducing greenhouse gas emissions, and investing in sustainable practices and technologies.

Aims of sustainable development:

1. Environmental protection: Sustainable development aims to protect the environment and natural resources to maintain their ecological balance and biodiversity.

2. Economic growth: Sustainable development aims to promote economic growth that is compatible with environmental protection and social well-being.

3. Social well-being: Sustainable development aims to improve the quality of life for all, including access to basic needs such as clean water, food, and healthcare.

Objectives of sustainable development:

1. Promoting sustainable resource use: The objective of sustainable development is to encourage the sustainable use of natural resources through responsible management and conservation practices.

2. Reducing greenhouse gas emissions: Sustainable development seeks to reduce greenhouse gas emissions and combat climate change through the promotion of clean energy sources and reducing fossil fuel consumption.

3. Promoting social equality: Sustainable development aims to promote social equality by ensuring access to basic needs, education, and healthcare for all.

Importance of sustainable development:

1. Environmental protection: Sustainable development is crucial for protecting the environment and natural resources, which are essential for maintaining ecological balance and biodiversity.

2. Economic growth: Sustainable development can promote long-term economic growth and stability by reducing reliance on non-renewable resources and encouraging investment in sustainable technologies and practices.

3. Social well-being: Sustainable development can improve the quality of life for all, including access to basic needs such as clean water, food, and healthcare.

4. Addressing global challenges: Sustainable development is necessary to address global challenges such as climate change, biodiversity loss, and poverty. It requires a coordinated effort by governments, businesses, and individuals to achieve a more sustainable future.

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