ObjectivesObjectives DefineDefine environmental science and compare environmental science and compare

environmental science with ecology.environmental science with ecology. ListList the five major fields of study that contribute the five major fields of study that contribute

to environmental science.to environmental science. DescribeDescribe the major environmental effects of the major environmental effects of

hunter-gatherers, the agricultural revolution, and hunter-gatherers, the agricultural revolution, and the Industrial Revolution.the Industrial Revolution.

DistinguishDistinguish between renewable and between renewable and nonrenewable resources.nonrenewable resources.

ClassifyClassify environmental problems into three environmental problems into three major categories.major categories.

ObjectivesObjectives DefineDefine environmental science and compare environmental science and compare

environmental science with ecology.environmental science with ecology. ListList the five major fields of study that contribute the five major fields of study that contribute

to environmental science.to environmental science. DescribeDescribe the major environmental effects of the major environmental effects of

hunter-gatherers, the agricultural revolution, and hunter-gatherers, the agricultural revolution, and the Industrial Revolution.the Industrial Revolution.

DistinguishDistinguish between renewable and between renewable and nonrenewable resources.nonrenewable resources.

ClassifyClassify environmental problems into three environmental problems into three major categories.major categories.

ObjectivesObjectives DescribeDescribe “The Tragedy of the Commons”.“The Tragedy of the Commons”. ExplainExplain the law of supply and demand.the law of supply and demand. ListList three differences between developed three differences between developed

and developing countries. and developing countries. ExplainExplain what sustainability is, and what sustainability is, and

describe why it is a goal of environmental describe why it is a goal of environmental science.science.

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What Is Environmental What Is Environmental Science?Science? Environmental ScienceEnvironmental Science is the study of is the study of

the air, water, and land surrounding an the air, water, and land surrounding an organism or a community, which ranges organism or a community, which ranges from a small area to Earth’s entire from a small area to Earth’s entire biosphere.biosphere.

It includes the study of the impact of It includes the study of the impact of humans on the environment.humans on the environment.

The Goals of The Goals of Environmental ScienceEnvironmental Science A major goal of environmental science is to A major goal of environmental science is to

understand and solve environmental understand and solve environmental problems.problems.

To accomplish this goal, environmental To accomplish this goal, environmental scientists study two main types of scientists study two main types of interactions between humans and their interactions between humans and their environment:environment:1)1) How our actions alter our environment.How our actions alter our environment.2)2) The use of natural resources.The use of natural resources.

Many Fields of StudyMany Fields of Study

Our Environment Through Our Environment Through TimeTime Wherever humans have hunted, grown Wherever humans have hunted, grown

food, or settled, they have changed the food, or settled, they have changed the environment.environment.

For example, the environmental change For example, the environmental change that occurred on Manhattan Island over that occurred on Manhattan Island over the last 300 years was immense, yet that the last 300 years was immense, yet that period of time was just a “blink” in human period of time was just a “blink” in human history.history.

Hunter-GatherersHunter-Gatherers Hunter-gatherers are people who obtain Hunter-gatherers are people who obtain

food by collecting plants and by hunting wild food by collecting plants and by hunting wild animals or scavenging their remains.animals or scavenging their remains.

Hunter-gatherers affect their environment in Hunter-gatherers affect their environment in many ways:many ways:1)1) Native American tribes hunted buffalo.Native American tribes hunted buffalo.2)2) The tribes also set fires to burn prairies and The tribes also set fires to burn prairies and

prevent the grow of trees. This left the prairie prevent the grow of trees. This left the prairie as an open grassland ideal for hunting bison.as an open grassland ideal for hunting bison.

Hunter-GatherersHunter-Gatherers In North America, a combination of rapid In North America, a combination of rapid

climate changes and overhunting by hunter-climate changes and overhunting by hunter-gatherers may have led to the disappearance gatherers may have led to the disappearance of some large mammal species, including:of some large mammal species, including:1)1) giant slothsgiant sloths2)2) giant bisongiant bison3)3) mastodonsmastodons4)4) cave bearscave bears5)5) saber-toothed catssaber-toothed cats

The Agricultural The Agricultural RevolutionRevolution AgricultureAgriculture is the raising of crops and is the raising of crops and

livestock for food or for other products that are livestock for food or for other products that are useful to humans.useful to humans.

The agricultural revolution allowed human The agricultural revolution allowed human populations to grow at an unprecedented rate.populations to grow at an unprecedented rate.

As populations grew, they began to As populations grew, they began to concentrate in smaller areas placing increased concentrate in smaller areas placing increased pressure on the local environments.pressure on the local environments.

The Agricultural The Agricultural RevolutionRevolution Many habitats were destroyed as Many habitats were destroyed as

grasslands, forests, and wetlands were grasslands, forests, and wetlands were replaced with farmland.replaced with farmland.

Replacing forest with farmland on a large Replacing forest with farmland on a large scale can cause soil loss, floods, and scale can cause soil loss, floods, and water shortages.water shortages.

The Agricultural The Agricultural RevolutionRevolution The slash-and-burn technique was one of The slash-and-burn technique was one of

the earliest ways that land was converted the earliest ways that land was converted to farmland.to farmland.

Much of this converted land was poorly Much of this converted land was poorly farmed and is no longer fertile.farmed and is no longer fertile.

The Industrial RevolutionThe Industrial Revolution The Industrial Revolution involved a shift The Industrial Revolution involved a shift

from energy sources such as animals and from energy sources such as animals and running water to fossil fuels such as coal running water to fossil fuels such as coal and oil.and oil.

This increased use of fossil fuels changed This increased use of fossil fuels changed society and greatly increased the society and greatly increased the efficiency of agriculture, industry, and efficiency of agriculture, industry, and transportation.transportation.

The Industrial RevolutionThe Industrial Revolution In factories, the large-scale production of In factories, the large-scale production of

goods became less expensive than the local goods became less expensive than the local production of handmade goods.production of handmade goods.

On the farm, machinery reduced the amount On the farm, machinery reduced the amount of land and human labor needed to produce of land and human labor needed to produce food.food.

With fewer people producing their own food, With fewer people producing their own food, the populations in urban areas steadily grew.the populations in urban areas steadily grew.

Improving the Quality of Improving the Quality of LifeLife The industrial Revolution introduced many The industrial Revolution introduced many

positive changes such as the light bulb.positive changes such as the light bulb. Agricultural productivity increased, and Agricultural productivity increased, and

sanitation, nutrition, and medical care sanitation, nutrition, and medical care vastly improved.vastly improved.

Improving the Quality of Improving the Quality of LifeLife Many of these products make life easier, Many of these products make life easier,

but we are now beginning to understand but we are now beginning to understand some of the environmental problems they some of the environmental problems they present.present.

In fact, much of environmental science is In fact, much of environmental science is concerned with the problems associated concerned with the problems associated with the Industrial Revolution.with the Industrial Revolution.

Spaceship EarthSpaceship Earth Earth can be compared to a spaceship Earth can be compared to a spaceship

traveling through space as it cannot dispose traveling through space as it cannot dispose of its waste or take on new supplies.of its waste or take on new supplies.

Earth is essentially a closed system.Earth is essentially a closed system. This means that the only thing that enters This means that the only thing that enters

the Earth’s atmosphere in large amounts is the Earth’s atmosphere in large amounts is energy from the sun, and the only thing that energy from the sun, and the only thing that leaves in large amounts is heat.leaves in large amounts is heat.

Spaceship EarthSpaceship Earth This type of closed system has some This type of closed system has some

potential problems.potential problems. Some resources are limited and as the Some resources are limited and as the

population grows the resources will be population grows the resources will be used more rapidly.used more rapidly.

There is also the possibility that we will There is also the possibility that we will produce wastes more quickly than we can produce wastes more quickly than we can dispose of them. dispose of them.

Spaceship EarthSpaceship Earth Environmental problems can occur on Environmental problems can occur on

different scales: local, regional, or global.different scales: local, regional, or global.• A local example would be your community A local example would be your community

discussing where to build a new landfill.discussing where to build a new landfill.• A regional example would be a polluted river A regional example would be a polluted river

1000 miles away affecting the region’s water.1000 miles away affecting the region’s water.• A global example would be the depletion of A global example would be the depletion of

the ozone layer.the ozone layer.

Population GrowthPopulation Growth The Industrial Revolution, modern The Industrial Revolution, modern

medicine, and sanitation all allowed the medicine, and sanitation all allowed the human population to grow faster than it human population to grow faster than it ever had before.ever had before.

Population GrowthPopulation Growth

Population GrowthPopulation Growth In the past 50 years, nations have used In the past 50 years, nations have used

vast amounts of resources to meet the vast amounts of resources to meet the worlds need for food.worlds need for food.

Producing enough food for large Producing enough food for large populations has environmental populations has environmental consequences such as habitat destruction consequences such as habitat destruction and pesticide pollution.and pesticide pollution.

Population GrowthPopulation Growth Most scientists think that the human Most scientists think that the human

population will almost double in the 21st population will almost double in the 21st century before it begins to stabilize.century before it begins to stabilize.

Because of these predictions, we can Because of these predictions, we can expect the pressure on the environment expect the pressure on the environment will continue to increase and the human will continue to increase and the human population and its need for food and population and its need for food and resources grow.resources grow.

What are our Main What are our Main Environmental Problems?Environmental Problems? Environmental problems can generally be Environmental problems can generally be

grouped into three categories:grouped into three categories:

1)1) Resource DepletionResource Depletion2)2) PollutionPollution3)3) Loss of BiodiversityLoss of Biodiversity

Resource DepletionResource Depletion Natural ResourcesNatural Resources are any natural are any natural

materials that are used by humans, such materials that are used by humans, such as, water, petroleum, minerals, forests, as, water, petroleum, minerals, forests, and animals.and animals.

Natural resources are classified as either a Natural resources are classified as either a renewable resources or a nonrenewable renewable resources or a nonrenewable resource.resource.

Resource DepletionResource Depletion Renewable resources Renewable resources

can be replaced can be replaced relatively quickly by relatively quickly by natural process.natural process.

Nonrenewable Nonrenewable resources form at a resources form at a much slower rate than much slower rate than they are consumed.they are consumed.

Resource DepletionResource Depletion

PollutionPollution PollutionPollution is an undesirable change in the is an undesirable change in the

natural environment that is caused by the natural environment that is caused by the introduction of substances that are harmful introduction of substances that are harmful to living organisms or by excessive to living organisms or by excessive wastes, heat, noise, or radiationwastes, heat, noise, or radiation

Much of the pollution that troubles us Much of the pollution that troubles us today is produced by human activities and today is produced by human activities and the accumulation of wastes.the accumulation of wastes.

PollutionPollution There are two main types of pollutants:There are two main types of pollutants:

• BiodegradableBiodegradable pollutants, which can be pollutants, which can be broken down by natural processes and broken down by natural processes and include materials such as newspaper.include materials such as newspaper.

• NondegradableNondegradable pollutants, which cannot be pollutants, which cannot be broken down by natural processes and broken down by natural processes and include materials such as mercury.include materials such as mercury.

Loss of BiodiversityLoss of Biodiversity BiodiversityBiodiversity is the variety of organisms in a is the variety of organisms in a

given area, the genetic variation within a given area, the genetic variation within a population, the variety of species in a population, the variety of species in a community, or the variety of communities in an community, or the variety of communities in an ecosystem.ecosystem.

The organisms that share the world with us The organisms that share the world with us can be considered natural resources.can be considered natural resources.

We depend on them for food, the oxygen we We depend on them for food, the oxygen we breathe, and for many other things.breathe, and for many other things.

Loss of BiodiversityLoss of Biodiversity Yet, only a fraction of all the species that once Yet, only a fraction of all the species that once

roamed the Earth are alive today, and many are roamed the Earth are alive today, and many are extinct.extinct.

Scientists think that if the current extinction rates Scientists think that if the current extinction rates continue, it may cause problems for the human continue, it may cause problems for the human population.population.

Many people also argue that all species have Many people also argue that all species have potential economic, scientific, aesthetics, and potential economic, scientific, aesthetics, and recreational value, so it is important to preserve recreational value, so it is important to preserve them.them.

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““The Tragedy of the The Tragedy of the Commons”Commons” In his essay, ecologist Garrett Hardin argued In his essay, ecologist Garrett Hardin argued

that the main difficulty in solving that the main difficulty in solving environmental problems is the conflict environmental problems is the conflict between the short-term interests of the between the short-term interests of the individual and the long-term welfare of individual and the long-term welfare of society.society.

The example he used was the commons, or The example he used was the commons, or the areas of land that belonged to the whole the areas of land that belonged to the whole village.village.

““The Tragedy of the The Tragedy of the Commons”Commons” It was in the best interest of the individual It was in the best interest of the individual

to put as many animals in the commons as to put as many animals in the commons as possible.possible.

However, if too many animals grazed on However, if too many animals grazed on the commons, they destroyed the grass.the commons, they destroyed the grass.

Once the grass was destroyed, everyone Once the grass was destroyed, everyone suffered because no one could raise suffered because no one could raise animals on the commons.animals on the commons.

““The Tragedy of the The Tragedy of the Commons”Commons” The commons were eventually replaced by The commons were eventually replaced by

closed fields owned by individuals. closed fields owned by individuals. Owners were now careful not to put too many Owners were now careful not to put too many

animals on their land, because overgrazing animals on their land, because overgrazing wouldn’t allow them to raise as many animals wouldn’t allow them to raise as many animals next year.next year.

Hardin’s point being that someone or some Hardin’s point being that someone or some group must take responsibility for maintaining group must take responsibility for maintaining a resource or it will become depleted.a resource or it will become depleted.

““The Tragedy of the The Tragedy of the Commons”Commons” Hardin’s point can be applied to our modern Hardin’s point can be applied to our modern

commons, natural resources.commons, natural resources. Humans live in societies, and in societies, we Humans live in societies, and in societies, we

can solve environmental problems by planning, can solve environmental problems by planning, organizing, considering the scientific evidence, organizing, considering the scientific evidence, and proposing a solution.and proposing a solution.

The solution may be to override the short-term The solution may be to override the short-term interests of the individual and improve the interests of the individual and improve the environment for everyone in the long run.environment for everyone in the long run.

““The Tragedy of the The Tragedy of the Commons”Commons”

Costs and BenefitsCosts and Benefits The cost of environmental solutions can The cost of environmental solutions can

be high.be high. A cost-benefit analysis balances the cost A cost-benefit analysis balances the cost

of the action against the benefits one of the action against the benefits one expects from it.expects from it.

Often, environmental regulations are Often, environmental regulations are passed on to the consumer or taxpayer.passed on to the consumer or taxpayer.

Developed and Developed and Developing CountriesDeveloping Countries Developed countries have higher incomes, Developed countries have higher incomes,

slower population growth, diverse slower population growth, diverse industrial economies, and stronger social industrial economies, and stronger social support.support.

Developing countries have lower average Developing countries have lower average incomes, simple agriculture-based incomes, simple agriculture-based communities, and rapid population growth.communities, and rapid population growth.

Population and Population and ConsumptionConsumption Almost all environmental problems can be Almost all environmental problems can be

traced back to two root causes:traced back to two root causes:• The human population in some areas is The human population in some areas is

growing too quickly for the local environment growing too quickly for the local environment to support.to support.

• People are using up, wasting, or polluting People are using up, wasting, or polluting many natural resources faster than they can many natural resources faster than they can be renewed, replaced, or cleaned up.be renewed, replaced, or cleaned up.

Local Population Local Population PressuresPressures In severely overpopulated regions, forests In severely overpopulated regions, forests

are stripped bare, topsoil is exhausted, are stripped bare, topsoil is exhausted, and animals are driven to extinction.and animals are driven to extinction.

In these areas, malnutrition, starvation, In these areas, malnutrition, starvation, and disease can be constant threats.and disease can be constant threats.

Local Population Local Population PressuresPressures In developing countries, millions of people In developing countries, millions of people

are starving.are starving. Yet these human populations tend to the Yet these human populations tend to the

grow the fastest.grow the fastest. Food production, education, and job Food production, education, and job

creation cannot keep pace with the creation cannot keep pace with the population growth, so each person gets population growth, so each person gets fewer resources as time goes by.fewer resources as time goes by.

Consumption TrendsConsumption Trends To support the higher quality of life, developed To support the higher quality of life, developed

countries are using much more of Earth’s countries are using much more of Earth’s resources.resources.

Developed nations use about 75 percent of the Developed nations use about 75 percent of the world’s resources, although they make up only world’s resources, although they make up only 20 percent of the world’s population.20 percent of the world’s population.

This rate of consumption creates more waste This rate of consumption creates more waste and pollution per person then in developing and pollution per person then in developing countries.countries.

Consumption TrendsConsumption Trends

Ecological FootprintsEcological Footprints

Ecological footprintsEcological footprints are calculations are calculations that show the productive area of Earth that show the productive area of Earth needed to support one person in a needed to support one person in a particular country.particular country.

Ecological FootprintsEcological Footprints An ecological An ecological

footprint is one way footprint is one way to express the to express the differences in differences in consumption consumption between nations.between nations.

A Sustainable WorldA Sustainable World SustainabilitySustainability is the condition in which is the condition in which

human needs are met in such a way that a human needs are met in such a way that a human population can survive indefinitely.human population can survive indefinitely.

Sustainability is a key goal of Sustainability is a key goal of environmental science.environmental science.

A Sustainable WorldA Sustainable World

A sustainable world is not unchanging as A sustainable world is not unchanging as technological advances and human technological advances and human civilizations continue to be productive.civilizations continue to be productive.

However, our current world is not However, our current world is not sustainable as the developed countries sustainable as the developed countries are using resources faster than they can are using resources faster than they can be replaced.be replaced.