The document provides a comprehensive overview of the environment, defining it as encompassing both physical elements, like air and water, and living components that make up ecosystems essential for sustaining life. It discusses the functions of the environment, including resource provision, waste assimilation, and enhancing quality of life, emphasizing the urgent need for sustainable management due to the crises caused by overexploitation and pollution. Additionally, it examines the impact of human activities, such as urbanization and industrialization, on global warming and ozone depletion, noting the critical need for international cooperation to address these environmental challenges.

1. 
Environment definition
and functions

2. 
Definition of Environment
▪ The environment encompasses all conditions and factors that
influence human life, including the totality of our surroundings and
the resources that impact our existence and quality of life. This
comprehensive definition highlights both the physical and living
components of the environment. Physical elements consist of air,
water, land, soil, climate, mountains, and minerals—resources
provided by nature as a free gift. Living elements include all forms
of life, such as plants, animals, forests, and fisheries. These biotic
and abiotic components interact continuously, forming ecosystems
that support life. The biosphere, which includes all ecosystems,
reflects the intricate balance between living organisms and their
physical surroundings, crucial for sustaining life on Earth.

3. 
Meaning of Environment
▪ The environment consists of two main components: physical
(abiotic) and living (biotic) elements. Physical elements include
air, water, land, soil, climate, mountains, minerals, and other
natural resources, which together provide the foundation for life.
Living elements, such as birds, plants, animals, forests, and
fisheries, interact with these physical components, creating
complex ecosystems that support biodiversity. The ecosystem
concept describes how living organisms rely on their physical
surroundings to thrive, and studying these relationships helps
understand how human activities affect natural processes and
ecosystems.

4. 
Functions of environment
▪ 1.Offers Resources for Production:-
▪ The environment provides essential physical resources like minerals, wood,
water, and soil, which are used as inputs in various production processes. These
resources are critical for sectors such as agriculture, industry, and energy
production, enabling economic growth and development. Proper management of
these resources is vital to prevent depletion and maintain their availability for
future generations.
▪ 2. Sustains Life:-
▪ Fundamental elements of the environment, including the sun, soil, water, and
air, are vital for sustaining life. These components support both plant and animal
life, ensuring the continuation of ecosystems. Biodiversity within these
ecosystems plays a crucial role in their resilience, allowing ecosystems to adapt
to changes and maintain balance, which is essential for survival.

5. 
▪ 3.Assimilates Waste:-
▪ Human activities, including production and consumption, generate waste, primarily in
the form of garbage and pollutants. The environment has a natural capacity to absorb and
break down these wastes, helping maintain cleanliness and prevent pollution. However,
the environment’s ability to handle waste is limited, and excessive waste generation can
overwhelm natural systems, leading to pollution and environmental degradation.
▪ 4. Enhances Quality of Life:
▪ Natural surroundings such as rivers, oceans, mountains, and forests significantly
enhance the quality of life. These environments provide aesthetic value, recreational
opportunities, and contribute to mental well-being. Scenic beauty and cultural connections
to nature help foster a sense of appreciation and responsibility towards preserving natural
landscapes for future generations.
▪ The carrying capacity of the environment, which is its ability to provide resources and
assimilate waste without becoming degraded, is a key consideration. Exceeding this
capacity can lead to environmental stress, emphasizing the need for sustainable
management.

6. 
Renewable Resources
▪ Renewable resources are those that can be naturally replenished
over time and are not likely to be exhausted if used sustainably.
Examples include wood from trees, sea animals, and other
biological resources. These resources have the ability to
regenerate, ensuring a continuous supply as long as their rate of
consumption does not exceed their rate of regeneration.
Sustainable management practices are essential to ensure the
long-term availability of these resources, particularly in the face of
increasing global demand. Renewable energy sources, such as
solar, wind, and hydropower, are increasingly recognized as vital
alternatives to non-renewable energy sources, helping reduce
environmental impacts.

7. 
Non-Renewable Resources
▪ Non-renewable resources are finite and will eventually be
depleted with continued use. Examples include fossil fuels like
coal, oil, and natural gas, which take millions of years to form but
are consumed much faster than they can be naturally
replenished. Once these resources are exhausted, they cannot
be replaced on a human time scale, posing significant
challenges for future energy and resource needs. The depletion
of these resources highlights the importance of transitioning to
more sustainable alternatives, such as renewable energy
sources, to meet future demands without causing further
environmental degradation.

8. 
ENVIRONMENTAL CRISIS
▪ We can appreciate the concept of environmental crisis better, if we
understand these two terms:
▪ Carrying Capacity of Environment:-it refers to the state of balance
between the rate at which natural resources are exploited and the
rate at which these resources are regenerated. Implying that the
resource endowment remains Intact. In other words, carrying
capacity permits exploitation of resources only to the extent that the
total resource endowment does not deplete, or it does not diminish,
but remains intact.
▪ Absorptive Capacity of Environment: It refers to ability of the
environment to absorb wastes occurring due to production and
consumption activities in the economy.

9. 
Factors causing Environmental Crisis
▪ Excessive exploitation of natural resources challenging (or exceeding) the carrying capacity of the
environment
▪ Generation of waste exceeding the absorptive capacity of the environment
▪ Impact: Environmental crisis manifest themselves in the form of global warming, climate change, ozone
depletion’ besides the depletion (or even extinction) of certain resources.
▪ It is a serious threat to the availability of production resources to the future generations. Implying that the
speed or pace of growth today would ultimately become unsustainable, threatening the quality of life of
future generations.
▪ The world today is facing environmental crisis of unprecedented levels. There is huge pressure on
environment on account of rising population and affluent consumption & production patterns.

10.  Environmental Crisis has high
opportunity cost
▪ Opportunity cost is the sacrifice made for enjoying an opportunity. This may be categorised as (1) avoidable,
and (ii) unavoidable. It is unavoidable when, for example, wheat is grown on a piece of land in place of rice.
Loss of output of rice is an unavoidable opportunity cost of producing wheat. Opportunity cost is avoidable
when, for example excessive smoke is emitted (than the permissible-limit), because of the poor
maintenance of the vehicles.
▪ Environmental crisis have high opportunity costs because of the following reasons:
▪ (i) The unsustainable development practices have polluted water bodies and dried up some rivers and
aquifers, which has made water an economic good.
▪ (ii) Intensive and extensive extraction of resources has exhausted some of the vital resources and now,
huge amounts of finances need to be devoted towards research and development to explore new
resources.
▪ (iii) Degradation of environment has increased the cost of maintaining a healthy lifestyle, air and water
pollution have resulted in increased incidence of respiratory and water borne diseases.
▪ (iv) Due to increasing emissions of greenhouse gases and the threat of unprecedented rate of climate
change

11. 
Causes of Environmental Crisis
▪ Principal causes of environmental crisis are as under:
▪ (1) Population Explosion: One of the main causes of population explosion. Pressure of population on land
has tremendously increased and consequently land has been ruthlessly exploited. Population explosion has
caused substantial conversion of forest land into industrial and residential buildings. Environmental crisis is
▪ (2) Widespread Poverty: A large section of the Indian population is absolutely wide. These people cut trees
for fuel wood which they sell to earn ther livelihood. This causes a massive erosion of natural capital
ultimately leading to a crisis.
▪ (3) Increasing Urbanisation: Increasing urbanisation has caused pressure on housing and other civic
amenities. It has resulted in increasing demand for land and excessive exploitation of other natural
resources.

12. 
▪ (4) Increasing Use of Insecticides, Pesticides and Chemical Fertilizers Increasing use of
chemical fertilizers, pesticides and insecticides has also added to environmental pollution.
▪ (5) Rapid Industrialisation: Rapid industrialisation has also contributed to air, water and noise
pollution. Industrial smoke is a serious pollutant.
▪ (6) Multiplicity of Transport Vehicles: Multiplicity of transport vehicles has substantially
increased noise and air pollution.
▪ (7) Disregard for the Civic Norms: The general public in India tends to disregard the civic
norms. Often, the roads are littered, and horns & loudspeakers are indiscriminately used.
▪ Briefly, environmental pollution is the consequence of rapid urbanisation and
industrialisation, besides man’s disregard to the civil norms. It is culminating into global
crisis, and needs urgent redressal at the national and international levels.

13. 
Global warming
▪ Meaning: It is a situation referring to a gradual but consistent increase in global temperature, thanks to environmental
pollution and deforestation’.
▪ Present Senario (Data): Owing to emission of Greenhouse Gases (carbon dioxide in particular, along with methane
and other such gases), the earth’s surface is becoming increasingly warmer, showing a rise of 0.6°C (or 1.1° F) during
the past century. The atmospheric concentrations of CO2 and CH4 have increased by 31 per cent and 149 per cent
respectively above pre-industrial levels since 1750.
▪ Causes: The major reasons for emission of greenhouse gases are:
▪ (i) burning of coal and petroleum products (emitting CO₂, methane, nitrous oxide),
▪ (ii) deforestation leading to increase in the amount of CO₂ in the atmosphere,
▪ (iii) increased cattle production and animal waste is a source of methane. Increased cattle production also leads to
deforestation, as more land is needed to accommodate increased number of animals, which indirectly leads to
increase in the amount of CO₂ in the atmosphere

14. 
▪ Impact: Warming temperature is escalating the melt of polar ice, in
turn, implying a rise in sea level. Consequently, ecological balance
is impaired, inflicting greater incidence of natural calamities.
Ultimately, it implies a threat to human life, though poor countries
are to be the first and worst sufferers.
▪ Steps Taken: To address the issue of climate change, an
international agreement, known as Kyoto Protocol was signed in
1997 at a UN Conference on Climate Change held in Kyoto, Japan.
The agreement focuses on reductions in emissions of greenhouse
gases by industrialised nations.

15. 
Ozone depletion
▪ Meaning: It refers to reduction in ozone (a protective layer) in the stratosphere.
▪ Causes: This occurs owing to the excessive presence of chlorine and bromine
compounds, like chlorofluorocarbons (CFCs) [used as cooling substances in air
conditioners & refrigerators and in aerosol propellants] and bromofluorocarbons
(halons) [used in fire extinguishers].
▪ Direct Impact: As ozone depletes, there is greater ultraviolet radiation reaching
the earth which is a danger to living organisms. In the recent past, nearly 5 per
cent depletion in ozone layer has been recorded which is an issue of global
concern.
▪ Ozone Depletion: A Reduction in Protective Layer in the Atmosphere
▪ Steps Taken: The Montreal Protocol has banned the use of CFC compound as
well as other chemical compounds which lead to depletion of ozone, such as
carbon tetrachloride, trichloroethane (also known as methyl chloroform), and
bromine compounds known as halons.

16.  The biggest question arises is:
▪ Are environmental problems new to this century? If so, why?
▪ The answer to this question requires some elaboration. In the early days when civilisation
just began, or before this phenomenal increase in population, and before countries took to
industrialisation, the demand for environmental resources and services was much less than
their supply. This meant that pollution was within the absorptive capacity of the environment
and the rate of resource extraction was less than the rate of regeneration of these resources.
Hence environmental problems did not arise. But with population explosion and with the
advent of industrial revolution to meet the growing needs of the expanding population, things
changed. The result was that the demand for resources for both production and consumption
went beyond the rate of regeneration of the resources; the pressure on the absorptive
capacity of the environment increased tremendously — this trend continues even today.
Thus what has happened is a reversal of supply-demand relationship for environmental
quality — we are now faced with increased demand for environmental resources and
services but their supply is limited due to overuse and misuse. Hence the environmental
issues of waste generation and pollution have become critical today.