Download Subject: Environmental Science Subject Code: L-T-P: 2-0

Subject
: Environmental Science
Subject Code : EV20001
L-T-P: 2-0-0
Prof. Sudha Goel
Civil Engineering
Credit: 2
Prof. Ashok K. Gupta
Civil Engineering
Prof. M. D. Behera
CORAL
Prof. A. Chakraborty
CORAL
Syllabus
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Ecology
Water Pollution
Water and Wastewater Treatment
Solid and Hazardous Waste Management
Air Pollution
Soil Pollution
Noise Pollution
Waste Minimization and Cleaner Production
Environmental Impact Assessment
Environmental science
Definition:
Environmental
science
is
an
interdisciplinary academic field that
integrates physical and biological
sciences (including physics, chemistry,
biology, soil science, geology, and
geography) to the study of the
environment, and the solution of
environmental problems.
• Environmental science provides an integrated,
quantitative, and interdisciplinary approach to
the study of environmental systems.
• Related areas of study include environmental
studies and environmental engineering.
• Environmental study incorporates more of the
social sciences for understanding human
relationships, perceptions and policies towards
the environment.
• Environmental engineering focuses on design
and technology for improving environmental
quality.
The Nature of Science
Science is a process used to solve problems or
develop an understanding of nature that involves
testing possible answers.
The scientific method is a way of gaining
information (facts) about the world by forming
possible solutions to questions, followed by
rigorous testing to determine if the proposed
solutions are valid.
Basic Assumptions in Science
Presumptions
• Specific causes exist for observed events
• These causes can be identified
• General rules or patterns can be used to
describe observations
• Repeated events probably have the same
cause
• Perceptions are not individualistic
• Fundamental rules of nature are universal
Elements of the Scientific Method
• Scientists distinguish between situations that are
merely correlated (happen together) and those that
are
correlated
and
show
cause-and-effect
relationships
• The scientific method requires a systematic search
for information and continual evaluation to
determine if previous ideas are still supported
• Scientific ideas undergo constant reevaluation,
criticism, and modification
Elements of the Scientific Method
• Observation occurs when we use our senses or
extensions of our senses to record an event
• Scientists refer to observations
thoughtful recognitions of events
as
careful,
• Observations often lead to additional questions
about the observations
• The way questions are asked will determine how one
goes about answering them
• Exploring other sources of knowledge is the next
step to gain more information
Elements of the Scientific Method
A hypothesis is a testable statement that
provides a possible answer to a question,
or an explanation for an observation.
A good hypothesis must be logical, account
for all relevant information currently available,
allow prediction of related future events, and
be testable.
– Given a choice, the simplest hypothesis with
the fewest assumptions is the most desirable.
Elements of the Scientific Method
An experiment is a re-creation of an event that
enables an investigator to support or disprove a
hypothesis
A controlled experiment divides the experiment
into two groups (experimental and control) that
differ by only one variable
Reproducibility is important to the scientific
method. A good experiment must be able to be
repeated by independent investigators to ensure
a lack of bias
Natural Environment
The natural environment, commonly referred to simply
as the environment, is all living and non-living things
that occur naturally on Earth or some part of it (e.g. the
natural environment in a country)
This includes complete ecological units that function
as natural systems without massive human
intervention, including all vegetation, animals,
microorganisms, rocks, atmosphere and natural
phenomena that occur within their boundaries
And it includes universal natural resources and
physical phenomena that lack clear-cut boundaries,
such as air, water, and climate, as well as energy,
radiation, electric charge, and magnetism, not
originating from human activity
Environmental Scientist
Environmental scientists work on subjects like ;
understanding of earth processes
evaluating alternative energy systems
pollution control and mitigation
natural resource management
the effects of global climate change
Environmental issues almost always include an interaction of
physical, chemical, and biological processes.
Environmental scientists bring a systems approach to the analysis
of environmental problems.
Key elements of an effective environmental scientist include the
ability to relate space and time relationships as well as
quantitative analysis.
How Environmental Science came alive ?
Environmental science came alive as a substantive, active field of
scientific investigation in the 1960s and 1970s driven by
(a) the need for a multi-disciplinary approach to analyze complex
environmental problems
(b) the arrival of substantive environmental laws requiring specific
environmental protocols of investigation and
(c) the growing public awareness of a need for action in
addressing environmental problems.
Rachael Carson's landmark environmental book Silent Spring along
with major environmental issues becoming very public, such as the
1969 Santa Barbara oil spill, and the Cuyahoga River of
Cleveland, Ohio, "catching fire" (also in 1969), and Gulf Oil Spill
2010 helped increase the visibility of environmental issues and
create this new field of study.
Components of EVS
• Ecology
• Atmospheric
• Science
• Environmental
Chemistry
• Geosciences
Ecology
An interdisciplinary analysis of an ecological system which is
being impacted by one or more stressors might include several
related environmental science fields.
For example, one might examine an estuarine setting where a
proposed industrial development could impact certain species
by water and air pollution.
For this study,
 biologists would describe the flora and fauna
 chemists would analyze the transport of water pollutants to the
marsh
 physicists would calculate air pollution emissions

 geologists would assist in understanding the marsh soils and
bay mud
Atmospheric Sciences
It focuses on the Earth's atmosphere, with an emphasis upon its interrelation to
other systems. Atmospheric sciences can include studies of meteorology,
greenhouse gas phenomena, atmospheric dispersion modeling of
airborne contaminants, sound propagation phenomena related to
noise pollution, and even light pollution.
Taking the example of the global warming phenomena,
 physicists create computer models of atmospheric circulation
and infra-red radiation transmission
 chemists examine the inventory of atmospheric chemicals and
their reactions
 biologists analyze the plant and animal contributions to carbon
dioxide fluxes
 meteorologists and oceanographers add additional breadth in
understanding the atmospheric and ocean dynamics.
Environmental Chemistry
It is the study of chemical alterations in the environment. Principal areas of
study include soil contamination and water pollution. The topics of analysis
include chemical degradation in the environment, multi-phase transport of
chemicals (for example, evaporation of a solvent containing lake to yield
solvent as an air pollutant), and chemical effects upon biota.
As an example study, consider the case of a leaking solvent tank which has
entered the habitat soil of an endangered species of amphibian.
As a method to resolve or understand the extent of soil contamination and
subsurface transport of solvent,
 Computer specialist with mathematics and physics background
will help to develop or implement a computer model
 Chemists would then characterize the molecular bonding of the
solvent to the specific soil type
 biologists would study the impacts upon soil arthropods,
plants, and ultimately pond-dwelling organisms that are the
food of the endangered amphibian
Geosciences
It includes,
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Environmental geology
Environmental soil science
Volcanic phenomena and evolution of the Earth's crust
Hydrology
Oceanography
As an example study of soils erosion,
 Soil scientists will do the calculations of surface runoff
 Fluvial geo-morphologists would assist in examining sediment
transport in overland flow
 Physicists would contribute by assessing the changes in light
transmission in the receiving waters
 Biologists would analyze subsequent impacts to aquatic flora and
fauna from increases in water turbidity
An Ecosystem Approach
• An ecosystem is a region in which the
organisms and the physical environment
form an interacting unit
• The task of an environmental scientist is
to recognize and understand the natural
interactions and changes taking place in
the world, and to integrate these with the
uses humans make of the natural world
The study of environmental science is
so
interesting,
frustrating,
and
challenging
because
of
the
interrelatedness
among
seeming
unrelated factors.
“When we try to pick out anything by itself, we find it
hitched to everything else in the Universe.”
John Muir
My First Summer in the Sierra, 1911
Climate System
About Climate System
Nature of the Climate System
The climate system is a compositing
of five major interactive adjoint
components: the atmosphere, the
hydrosphere with the oceans, the
cryosphere, the lithosphere, and the
biosphere.
The atmosphere, hydrosphere, cryosphere, and
biosphere act as cascading system linked by
complex physical processes involving fluxes of
energy, momentum, and matter across the
boundaries and generating numerous feedback
mechanisms.
The components of the climatic system are
heterogeneous thermo-hydrodynamical systems,
which can be characterized by their chemical
composition
and
their
thermodynamic
and
mechanical states. The thermodynamic states are
specified, in general, by certain intensive variables
(e.g., temperature, pressure, specific humidity,
specific energy, density and salinity) whereas the
mechanical state is defined by other intensives
variables that characterize the motions (e.g. , forces
and velocities).
Thermodynamic System
Feedback System
Consequences for Human Wellbeing
The loss of services
derived
from
ecosystems is a
significant barrier to
the achievement of
the Millennium.
Development Goals
to reduce poverty,
hunger, and disease.
Unprecedented Change
• Humans have made unprecedented changes to
ecosystems in recent decades to meet growing
demands for food, fresh water, fiber, and energy
• These changes have helped to improve the lives of
billions, but at the same time they weakened nature’s
ability to deliver other key services such as
purification of air and water, protection from
disasters, and the provision of medicines
• The pressures on ecosystems will increase globally
in coming decades unless human attitudes MEA and
actions change
Key Problems
Among the outstanding
problems identified by this
assessment are the dire
state of many of the
world’s fish stocks; the
intense vulnerability of the
2 billion people living in
dry regions to the loss of
ecosystem
services,
including water supply;
and the growing threat to
ecosystems
from
climate
change
and
nutrient pollution.
Environmental Ethics
 Ethics is one branch of philosophy; it seeks to
define what is right and what is wrong.
 Ethics can help us understand what actions are
wrong and why they are wrong.
 Not all cultures share the same ethical
commitments. Cultural relativism in ethics
acknowledges these differences exist.
 Despite the presence of some differences, there
are many cases in which ethical commitments
can and should be globally agreed upon.
Ethics and Laws
• Ideally, the laws of a nation or community
should match the ethical commitments of
those living there
• In the case of environmental issues, care
needs to be taken over when it is appropriate
to legislate something and when action
should be left to the individual’s sense of
right and wrong
• A strong personal ethical commitment can
help guide behavior in the absence of
supporting laws
Conflicting Ethical Positions
• Sometimes an individual’s ethical commitments
can conflict with each other.
• A mayor might have an ethical commitment to
preserving land in a city but also have an ethical
commitment to bringing in jobs associated with
construction of a new factory.
In many cases, what is good for the environment
is also good for people.
• While forest protection may reduce logging jobs,
a healthier forest might lead to new jobs in
recreation, fisheries, and tourism.
Three Philosophical Approaches to
Environmental Ethics
Anthropocentrism (human-centered)
•
This view holds that all environmental responsibility is derived from
human interests.
– Assumes that only humans are morally significant.
– Assumes nature is an instrument for human manipulation.
Biocentrism (life-centered)
•
All life forms have an inherent right to exist.
Ecocentrism
•
This view maintains that the environment deserves direct moral
consideration, not consideration derived from human or animal
interests.
Three Philosophical Approaches to
Environmental Ethics
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“A thing is right when it tends to preserve the
integrity, stability, and beauty of the biotic
community. It is wrong when it tends
otherwise….We abuse land because we regard
it as a commodity belonging to us. When we see
land as a community to which we belong, we
may begin to use it with love and respect.”
—Aldo Leopold
A Sand County Almanac, 1949
Environmental Attitudes
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Because ethical commitments pull in different
directions at different times, it is often easier to
talk in terms of environmental attitudes or
approaches.
The three most common attitudes/approaches
are:
• Development approach
• Preservation approach
• Conservation approach
Environmental Attitudes
Development,
preservation,
and
conservation are different attitudes toward
nature.
These attitudes reflect a person’s ethical
commitments.
Development
This approach is the most anthropocentric.
• It assumes the human race is, and should be, master
of nature.
• It assumes that the Earth and its resources exist
solely for our benefit and pleasure.
• This approach is reinforced by the capitalist work
ethic.
• This approach thinks highly of human creativity and
holds that continual economic growth is a moral ideal
for society.
Preservation
This approach is the most ecocentric.
• It holds that nature has intrinsic value apart from
human uses.
– Preservationists such as John Muir, Ralph Waldo
Emerson, Henry David Thoreau, and Walt Whitman
articulated their positions differently, but all viewed
nature as a refuge from economic activity, not as a
resource for it.
Some preservationists wish to keep large parts of
nature intact for aesthetic or recreational reasons
(anthropocentric principles).
Conservation
This approach finds a balance between
unrestrained
development
and
preservationism.
Conservationism promotes human wellbeing but considers a wider range of longterm human goods in its decisions about
environmental management.
Many of the ideas in conservationism have
been incorporated into an approach known
as sustainable development.
Sustainable Development
Sustainable Development
is often defined as:
“Meeting the needs of the present without
compromising
the
ability
of
future
generations to meet their own needs”
World Commission on Economic Development.
(1987). Our Common Future. England: Oxford
University Press.
Environmental Justice
• In 1998, the Environmental Protection Agency (EPA)
defined environmental justice as fair treatment,
meaning:
“No group of people, including racial, ethnic, or
socioeconomic
groups,
should
bear
a
disproportionate
share
of
the
negative
environmental
consequences
resulting
from
industrial, municipal, and commercial operations or
the execution of federal, state, local, and tribal
programs and policies.”
• Environmental justice is closely related to civil
rights.
Green Business Concepts
• It makes little sense to preserve the environment
if preservation causes economic collapse.
• Nor does it make sense to maintain industrial
productivity at the cost of breathable air, clean
water, wildlife, parks, and wilderness.
• Natural capitalism is the idea that businesses
can both expand their profits and take good care
of the environment.
• The 3M Company is estimated to have saved up
to $500 million over the last 20 years through its
Pollution Prevention Pays (3P) program.
Green Business Concepts
• Industrial ecology links industrial production and
environmental quality.
• It models industrial production and biological
production, forcing industry to account for where
waste is going.
• In nature, nothing is wasted or discarded; all
materials ultimately get reused.
• A pollutant is a resource out of place.
• Good environmental practices are good economics.
References
Environmental Science by J. Miller
Physics of Climate by Peixoto and Oort
Web sources.