ENVIRONMENTAL

SCIENCES
 INTRODUCTION

• Environment can be defined as a sum total of all the living and non-living elements and
their effects that influence human life.
• While all living or biotic elements are animals, plants, forests, fisheries, and birds, non-
living or abiotic elements include water, land, sunlight, rocks, and air.
Components of
Environment

▪ Atmosphere
▪ Hydrosphere
▪ Lithosphere
▪ Biosphere
 Atmosphere

• The atmosphere is a mixture of gases that surrounds the Earth.

• It helps make life possible by providing us with air to breathe, shielding us from harmful
ultraviolet (UV) radiation coming from the Sun, trapping heat to warm the planet, and
preventing extreme temperature differences between day and night.

Gases in Earth's Atmosphere

▪ 78% nitrogen(N2)
▪ 21% oxygen (O2),
▪ The remaining less than 1% of the atmosphere is a mixture of gases, including argon(Ar)
and carbon dioxide (CO2)
▪ . There are also many, tiny, solid or liquid particles, called aerosols, in the atmosphere. Aerosols
can be made of dust, spores and pollen, salt from sea spray, volcanic ash, smoke, and
pollutants introduced through human activity.
 Atmosphere

Layers of Earth's Atmosphere

▪ Troposphere
▪ Stratosphere
▪ Mesosphere
▪ Thermosphere
▪ Exosphere
 Atmosphere

1. The Troposphere

• The troposphere is the lowest layer of Earth's atmosphere.

• Most of the mass (about 75-80%) of the atmosphere is in the troposphere.
• Most types of clouds are found in the troposphere, and almost all weather occurs
within this layer.
• The troposphere is by far the wettest layer of the atmosphere (all of the other layers
contain very little moisture).
• Goes upto 12km
• Temperature and air pressure both decrease as you go high
• Temperature decreases upto -53oC.
• ,
 Atmosphere

1. The stratosphere

• The stratosphere is a layer of Earth's atmosphere.

• . It is the second layer of the atmosphere as you go upward.
• The troposphere the lowest layer, is right below the stratosphere.
• OZONE a type of oxygen molecule that is relatively abundant in the stratosphere, heats
this layer as it absorbs energy from incoming ultraviolet radiation from the Sun.
• Temperature increase and comes to -03oC.
 Atmosphere

3. THE MESOSPHERE
• The mesosphere is a layer of Earth's atmosphere. The mesosphere is directly above
the stratosphere and below the thermosphere

• It extends from about 50 to 85 km (31 to 53 miles) above our planet.

• Temperature decreases with height throughout the mesosphere.

• The coldest temperatures in Earth's atmosphere, about -90° C (-130° F), are found
near the top of this layer.
 Atmosphere

4. Thermosphere

• It is the layer that is located between the mesosphere and the exosphere. It has an
extension that begins between 80 to 120 kilometers from the Earth.

• In this layer, the ultraviolet radiation, and especially the gamma rays and X rays
originated by the Sun.

• There is constantly ionization of sodium atoms and various types of molecules going
on. This process of ionization makes the gases due to which temperature of
thermosphere raises by several hundred degrees.

• Temperature rises up to 2000oC

 Atmosphere

Importance of
Atmosphere
 HYDROSPHERE

• Hydrosphere, discontinuous layer of water at or near Earth’s surface. It

includes all liquid and frozen surface waters, groundwater held in soil
and rock, and atmospheric water vapor.
 Water Cycle

• Hydrosphere, discontinuous layer of water at or near Earth’s surface. It

includes all liquid and frozen surface waters, groundwater held in soil
and rock, and atmospheric water vapor.
 BIOSPHERE

• The biosphere is the thin life-supporting stratum of Earth’s surface, extending from a few
kilometres into the atmosphere to the deep-sea vents of the ocean.
• It is composed of living organisms and nonliving factors from which the organisms derive
energy and nutrients.

• The two components of the biosphere are called the abiotic and the biotic.

• The abiotic, or nonliving, portion of each ecosystem includes the flow of energy, nutrients,
water, and gases and the concentrations of organic and inorganic substances in the
environment.

• The second component is the biotic, or living organism, portion, which includes producers,
consumers, and decomposers.
 World Biomes

• Biomes are defined as "the world's major communities, classified according to the
predominant vegetation and characterized by adaptations of organisms to that particular
environment
Forest Biome
The word forest broadly describes an area that has a large number of trees. There are three
general types of forest that exist: temperate, tropical, and boreal. Experts estimate that these
forests cover approximately one-third of Earth’s surface.

Temperate forests are found across eastern North America and Eurasia. The temperatures
of temperate forests vary throughout the year because of the four distinct seasons at these
latitudes. Precipitation is abundant and lends to fertile soil that is able to support
diverse flora like maples, oak, and birch. Deer, squirrels, and bears are just a few examples of
the fauna that call temperate forests home.

Tropical forests are common to areas near the equator, such as Southeast Asia, sub-Saharan
Africa, and Central America. Temperatures in tropical forests have been reported to range
between 20 and 31°C (68 and 88°F).
 World Biomes

Forest Biome

• The third type of forest is the boreal forest, also known as taiga. Boreal forests, one of the
world’s largest land biomes, are found across Siberia, Scandinavia, and North America
(Alaska and Canada).

• Boreal forests have a significant role in removing carbon dioxide from the atmosphere.
Temperatures in boreal forests are, on average, below freezing.
 World Biomes

Desert Biome

• Deserts cover about one fifth of the Earth's surface and occur where rainfall is less than 50
cm/year.

• Although most deserts, such as the Sahara of North Africa and the deserts of the
southwestern U.S., Mexico, and Australia, occur at low latitudes, another kind of desert,
cold deserts, occur in the basin and range area of Utah and Nevada and in parts of
western Asia.

• Most deserts have a considerable amount of specialized vegetation, as well as specialized

vertebrate and invertebrate animals..
 World Biomes
Desert
Biome
Soils often have abundant nutrients because they need only water to become very
productive and have little or no organic matter. Disturbances are common in the form of
occasional fires or cold weather, and sudden, infrequent, but intense rains that cause
flooding.

There are relatively few large mammals in deserts because most are not capable of storing
sufficient water and withstanding the heat. Deserts often provide little shelter from the sun
for large animals. The dominant animals of warm deserts are nonmammalian vertebrates,
such as reptiles. Mammals are usually small, like the kangaroo mice of North American
deserts.
 World Biomes

Grassland
Biome

• Limited annual rainfall.

• The dry climate throughout the year.
• Lack of nutrients in the soil.
• Grasslands are prone to drought and uncertain precipitation.
• Frequent fire due to semi-arid climate and flash lighting.
• Poor vegetation growth dominated by grasses.
 World Biomes

Tundra Biome
• For most of the year, the tundra biome is a cold, frozen landscape.

• This biome has a short growing season, followed by harsh conditions that the plants and
animals in the region need special adaptations to survive.

• Tundra form in two distinct cold and dry regions. Arctic tundra are found on high-latitude
landmasses, above the Arctic Circle—in Alaska, Canada, Russia, Greenland, Iceland, and
Scandinavia, for example—or on far southern regions, like Antarctica. Alpine tundra are
located at very high elevations atop mountains, where overnight temperatures fall below
freezing.

• Tundra regions typically get less than 25 centimeters (10 inches) of precipitation annually,
which means these areas are also considered deserts.

• They have long, cold winters with high winds and average temperatures below freezing for
six to ten months of the year.
 Environmental Pollution

• Environmental Pollution can be defined as any undesirable change in physical,

chemical, or biological characteristics of any component of the environment i.e. air,
water, soil which can cause harmful effects on various forms of life or property.

TYPES OF POLLUTION
Air Pollution
Water Pollution
Land Pollution/ Soil Pollution
Sound Pollution/ Noise Pollution

• Generally, Substances that causes pollution is called as Pollutants.

 WATER POLLUTION
• Water Pollution can be defined as alteration in physical, chemical, or
biological characteristics of water through natural or human activities and
making it unsuitable for its designated use.

• Physical characteristic refers to color, taste, turbidity and smell of water.

• Chemical characteristic refers to: pH, TDS, DO, COD, BOD.

• Biological characteristic refers to- presence of biological components i.e.

bacteria,
fungi, etc.

• On Earth, only 1/3th part of available water from ice and groundwater is pure,
rest is
 WATER POLLUTION

The sources of water pollution can be classified as:

• Municipal Waste Water

• Industrial Pollution- wastes from industries, metals, etc.
• Inorganic Pollutants- fine particles of heavy metals, chlorides,
• Organic Pollutants- oil, phenols, organic acids like HNO3 etc.
• Agricultural Wastes- Chemical fertilizers, pesticides
• Marine Pollution – Grease, oils, detergents,
• Thermal pollution -Thermal plants and nuclear plants
 WATER POLLUTION

EFFECT OF WATER POLLUTION

• Polluted water has less amount of Dissolved oxygen (DO) content which is important
form sensitive organisms, thereby eliminates sensitive organisms.

• Excess of nitrate in drinking water is dangerous for infants and human health, excess
fluoride cause neuromuscular disorder and teeth deformity, hardening of bones and
painful joints.

• Biological magnification and eutrophication.

 WATER POLLUTION

CONTROL OF WATER POLLUTION

• Usage of water should be minimized by changing the techniques involved.

• Recycling and treatment of water should be used to the maximum extent

possible.

• The quantity of discharge of wastewater can be minimized.

• Excessive use of pesticides and fertilizers should be avoided.

• Organic farming and efficient use of animal residues as fertilizers

 AIR POLLUTION

• Air pollution is the introduction of chemicals, particulate matter, or biological materials that cause
harm or discomfort to humans or other living organisms, or cause damage to the natural
environment or built environment, into the atmosphere.

• A substance in the air that can cause harm to humans and the environment is known as an air
pollutant.
 AIR POLLUTION

CAUSES OF AIR POLLUTION

• Carbon dioxide-this happens because of deforestation and fossil fuel burning.

• Sulfur dioxide –Due to the burning of sulfur containing compounds of fossil

fuels (Coal & petroleum).

• Sulfur oxides- very dangerous to humans at a high concentration. Sulfur in the

atmosphere is responsible for acid rain.

• Nitrous Oxide (N2O)- Fossil fuel

• Secondary Pollutants- Photochemical smog(PAN), Acid rain, O3,

 AIR POLLUTION

EFFECT OF AIR POLLUTION

• Cause Global warming due to excess concentration of CO2, NOx, CFC, SO2.

• Causes Green House Effect.

• Causes Acid rain.

• Nitrogen oxides in air cause Problems in the lungs, respiratory systems and
causes
• asthma and bronchitis.

• Suspended particulate matter in air causes lung irritation reduces

development of RBC and pulmonary malfunctioning.

• CO causes severe headache, irritation to mucous membrane, unconsciousness

and death.

• Photochemical smog cause asthma and bronchitis.

 AIR POLLUTION

CONTROL OF AIR POLLUTION

• Policy measures- Environment Protection Act, 1986.

• Modification of industrial process and selection of suitable fuels and its

utilization.

• Collection of pollutants and convert it into less toxic forms b different methods.

• Mass Emission Standards

• Fuel Quality Specifications

• Alternate Fuels-Initiatives