1. Welcome to Environmental Science

2. Objectives: Define environment
Define and describe the field of environmental science
What is exponential growth
What are the important environmental issues
Define a sustainable system
What role do environmental indicators play

3. Environment: the total of our surroundings
All the things around us with which we interact:
Biotic  Living things
Animals, plants, forests, fungi, etc.
Abiotic  Nonliving things
Continents, oceans, clouds, soil, rocks
Our built environment
Buildings, human-created living centers
Social relationships and institutions
Environment is everything that affects a living organism (any unique form of life).

4. What is Environmental Science?
Its is an interdisciplinary science that uses concepts and information from natural sciences such as ecology, biology, chemistry, and geology and social sciences such as economics, politics, and ethics to help understand –
How the earth works,
How we are affecting the earth’s life-support systems (environment), and
How to deal with the environmental problems we face

5. Environment  Impacts  Humans
Environmental Science is especially broad because it encompasses:
Natural sciences: disciplines that examine the natural world
Environmental Science programs
Social sciences: disciplines that address human interactions and institutions
Environmental Studies programs

6. Environmental Science is NOT Environmentalism
The pursuit of knowledge about the natural world
Scientists try to remain objective
Environmentalism
A social movement dedicated to protecting the natural world

8. The cast of major characters :
Ecologists, who are biological scientists studying relationships between living organisms and their environment.
Environmental scientists, use information to
understand how Earth works,
learn how humans interact with Earth, and 
develop solutions to environmental problems.
Conservation biologists, created a multidisciplinary science in the 1970s to 
investigate human impacts on the diversity of life found on Earth (biodiversity) and
develop practical plans for preserving such biodiversity.

9. Environmentalists, are 1) concerned about the impact of people on environmental quality and 2) believe some human actions are degrading parts of Earth's life-support systems for humans and many other forms of life. Some of their beliefs and proposals for dealing with environmental problems are based on scientific information and concepts, and some are based on their social and ethical environmental beliefs (environmental worldviews). Environmentalists are a broad group of people from different economic groups and with different political persuasions.
Preservationists, are concerned primarily with setting aside or protecting undisturbed natural areas from harmful human activities.
Conservationists, are concerned with using natural areas and wildlife in ways that sustain them for current and future generations of humans and other forms of life.

10. What defines an Environmental Problem?
The perception of what constitutes a problem varies between individuals and societies (place) and time.
Ex. DDT, a pesticide
In developing countries: its welcome because it kills malaria-carrying mosquitoes, lice and other insects
In developed countries: not welcome, due to health risks
(found to be a carcinogen a half century later)

11. What Is Exponential Growth?
Fold a piece of paper in half to double its thickness.
If you could do this 42 times, the stack would reach from Earth to Moon, 386,400 kilometers (240,000 miles) away.
If you could double it 50 times, the folded paper would almost reach the sun, 149 million kilometers (93 million miles) away!

12. Important Environmental Issues
population growth 
increasing resource use
loss of biodiversity
destruction and degradation of wildlife habitats
premature extinction of plants and animals, 
poverty
pollution 
All are interconnected and growing exponentially

13. Populations Growth Human population growth: J-shaped curve
The world’s population has increased sixfold in the past 200 years

14. Resources = Capital
To economists, capital is wealth used to sustain a business and to generate more wealth. By analogy, we can think of 
energy from the sun as solar capital and
the planet's air, water, soil, wildlife, forests, rangelands, fisheries, minerals, and natural purification, recycling, and pest control processes as natural resources, or natural capital
Solar energy includes direct sunlight and indirect forms of solar energy such as  (1) wind power,  (2) hydropower (energy from flowing water), and  (3) biomass (direct solar energy converted to chemical energy stored in biological sources of energy such as wood).

15. Types of Resources
Perpetual Resources – Resources that are renewed continuously
Renewable Resources – Resources that can be replenished fairly rapidly (hours to several decades) through natural processes as long as it is not used up faster than it is replaced
Nonrenewable Resources – Resources that can be environmentally depleted to the point where it costs to much to obtain what is left. The sources can be degraded economically when the cost of extracting and using what is left exceeds its economic value.

16. Resources Perpetual Nonrenewable Winds, tides, flowing water Fossil
fuels
Metallic
minerals
Non-
metallic
minerals
Direct
solar
energy
(iron,
copper,
aluminum)
(clay,
sand,
phosphates)
Renewable
Fresh
air
Fresh
water
Fertile
soil
Plants and
animals
(biodiversity)

17. Perpetual and Renewable Resources
Solar energy is called a perpetual resource because on a human time scale it is renewed continuously. It is expected to last at least 6 billion years as the sun completes its life cycle.
On a human time scale, a renewable resource can be replenished fairly rapidly (hours to several decades) through natural processes as long as it is not used up faster than it is replaced. Examples are:
forests, 
grasslands, 
wild animals, 
fresh water,
fresh air, and
fertile soil.

18. Increasing Renewable Resource Use
Renewable resources can be depleted or degraded. The highest rate at which a renewable resource can be used indefinitely without reducing its available supply is called sustainable yield.
If we exceed a renewable resource's natural replacement rate (sustainable yield), the available supply begins to shrink, a process known as environmental degradation.

19. Examples of such degradation include:
urbanization of productive land,
waterlogging and salt buildup in soil,
excessive topsoil erosion, 
deforestation,
groundwater depletion, 
overgrazing of grasslands by livestock, 
reduction in Earth's forms of wildlife (biodiversity) by elimination of habitats and species, and 
pollution

20. Nonrenewable Resources
Nonrenewable resources exist in a fixed quantity or stock in Earth's crust. On a time scale of millions to billions of years, geological processes can renew such resources. However, on the much shorter human time scale of hundreds to thousands of years, these resources can be depleted much faster than they are formed.
These exhaustible resources include 
energy resources (such as coal, oil, and natural gas, which cannot be recycled), 
metallic mineral resources (such as iron, copper, and aluminum, which can be recycled), and 
nonmetallic mineral resources (such as salt, clay, sand, and phosphates, which usually are difficult or too costly to recycle).

21. Increased Nonrenewable Resource Use
We never completely exhaust a nonrenewable mineral resource. However, such a resource becomes economically depleted when the costs of extracting and using what is left exceeds its economic value. At that point, we have six choices: 
try to find more, 
recycle or reuse existing supplies (except for nonrenewable energy resources, which cannot be recycled or reused), 
waste less, 
use less, 
try to develop a substitute, or 
wait millions of years for more to be produced.
Some nonrenewable material resources, such as copper and aluminum, can be recycled or reused to extend supplies.

22. Loss of Biodiversity
Biodiversity is the variety of earth's species, the genes they contain, the ecosystem in which they live, and the ecosystem processes of energy flow and nutrient cycling that sustain all life.
It exists on three scales:
Genetic diversity is a measure of the genetic variation among individuals
Species diversity indicates the number of species in a region or in a particular type of habitat.
Ecosystem diversity is a measure of the diversity of ecosystems or habitats that exist in a given region.

23. Environmental Effects of Poverty
Daily life is a harsh struggle for the estimated one of every two people on Earth who try to survive on an income of $1-3 (U.S.) per day.
Such acute poverty is related to environmental quality and people's quality of life because poor people often
Deplete and degrade local forests, soil, grasslands, wildlife, and water supplies for short-term survival. They do not have the luxury of worrying about longterm supplies of natural resources when their daily life is focused on getting enough food and water too survive.
Live in areas with high levels of air and water pollution and with the greatest risk of natural disasters such as floods, earthquakes, hurricanes, and volcanic eruptions.
Spend an average of 4-6 hours 
per day searching for and carrying fuelwood and 
per week drawing and carrying water.

24. Environmental Effects of Poverty
Have many children as a form of economic security.
Must take jobs (if they can find them) that subject them to unhealthy and unsafe working conditions at very low pay.
Die prematurely from preventable health problems. According to the World Health Organization (WHO), each year at least 10 million of the desperately poor die prematurely of
malnutrition (lack of protein and other nutrients needed for good health),
infectious diseases caused by drinking contaminated water, and 
increased susceptibility to infectious diseases

25. Pollution
Pollution is any addition to air, water, soil, or food that threatens the health, survival, or activities of humans or other living organisms.
Pollutants can enter the environment 
naturally (for example, from volcanic eruptions) or 
through human (anthropogenic) activities (for example, from burning coal). Most pollution from human activities occurs in or near urban and industrial areas, where pollutants are concentrated. Industrialized agriculture also is a major source of pollution.

26. Two types of pollutant sources:
Point sources, where pollutants come from single, identifiable sources. Examples are the
smokestack of a coal-burning power plant,
drainpipe of a factory, or 
exhaust pipe of an automobile.
Nonpoint sources, where pollutants come from dispersed (and often difficult to identify) sources. Examples are 
runoff of fertilizers and pesticides (from farmlands, golf courses, and suburban lawns and gardens) into streams and lakes and 
pesticides sprayed into the air or blown by the wind into the atmosphere.
It is much easier and cheaper to identify and control pollution from point sources than from widely dispersed nonpoint sources.

27. Sustainability
Sustainability – Living on Earth in a way that allows humans to use its resources without depriving future generations of those resources.
Example –
Imagine you inherit $1 million. Invest this capital at 10% interest per year, and you will have a sustainable annual income of $100,000 without depleting your capital. If you spend $200,000 a year, your $1 million will be gone early in the 7th year; even if you spend only $110,000 a year you will be bankrupt early in the 18th year.
THE LESSON - Protect your capital!!!
Deplete your capital, and you move from a sustainable to unsustainable lifestyle.

28. What is an Environmentally Sustainable Society?
Living Sustainably means –
living off the natural income replenished by soils, plants, air, and water, and
not depleting the earth’s endowment of natural capital that supplies this income.

29. Four Scientific Principles of Sustainability: Copy Nature
Reliance on
Solar Energy
Biodiversity
Nutrient Recycling
Population Control

30. Scientific Principles of Sustainability
Reliance on solar energy- the sun warms the planet and supports photosynthesis used by plants to provide food for us and other animals.
Biodiversity- a great variety of genes, species, ecosystems, and ecological processes have provided many ways to adapt to changing environmental conditions throughout 3.7 billion year history of life on earth.
Population Control- competition for limited resources among species places a limit on how much any one population can grow. If a population grows beyond those limits, its size decrease from changes in birth rates and death rates.
Nutrient Recycling- Natural processes recycle all chemicals or nutrients that plants and animals need to stay alive. In this recycling process, the wastes or dead bodies of all organisms become food or resources for other organisms.

31. Are We Living Sustainable?
Environmentalists and many leading scientists believe we are living unsustainably by depleting and degrading Earth's natural capital at an accelerating rate as our population and demands on Earth's resources and life-sustaining processes increase exponentially.
Other analysts do not believe we are living unsustainably. They contend that
environmentalists have exaggerated the seriousness of population and environmental problems, and 
any population, resource, and environmental problems we face can be overcome by human ingenuity and technological advances.

32. Environmental Indicators
To describe the health and quality of natural systems, environmental scientists use environmental indicators.
Environmental Indicators describe the current state of an environmental system.
These indicators do not always tell us what is causing a change, but they do tell us when we might need to look more deeply into a particular issue.
This information can be used to guide us toward sustainability, by which we mean living on Earth in a way that allows us to use its resources without depriving future generations of those resources.

35. Solutions
Principles of Sustainability
How Nature Works
Lessons for Us
Runs on renewable
solar energy.
Rely mostly on renewable solar energy.
Recycles nutrients
and wastes. There
is little waste in
nature.
Prevent and reduce
pollution and recycle
and reuse resources.
Preserve biodiversity
by protecting ecosystem services and habitats
and preventing premature extinction of species.
Uses biodiversity to
maintain itself and adapt to new environ-
mental conditions.
Controls a species’
population size and
resource use by interactions with its
environment and other species.
Reduce human births and wasteful resource
use to prevent
environmental overload and depletion and degradation of resources.

37. Conclusion
Environmental science helps us understand our relationship with the environment and informs our attempts to solve and prevent problems.
Identifying a problem is the first step in solving it
Solving environmental problems can move us towards health, longevity, peace and prosperity
Environmental science can help us find balanced solutions to environmental problems for sustainable development