Do Now

• Name/List 3 reasons why the field of environmental science is important?

Humans and the Environment

Objective: Students will be able to define sustainability and describe ways to conserve

natural resources.

What is Environmental Science?

• Environmental Science is the study of the impact of humans on the environment

• It is considered an applied scienceapplied science – meaning that it focuses on tangible problems more than theoretical ideas

• Environmental Science is also interdisciplinaryinterdisciplinary – it involves many areas of study

• Some of the sciences that are a part of environmental science are:– Ecology, chemistry, geology, botany, zoology,

paleontology– Economics, law, politics, and geography

Population Growth

• The Industrial Revolution, modern medicine, and sanitation all allowed the human population to grow faster than it ever had before.

Population Growth

• In the past 50 years, nations have used vast amounts of resources to meet the worlds need for food.

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

Population Growth

• Most scientists think that the human population will almost double in the 21st century before it begins to stabilize.

What is the current world population?

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

What environmental problems have you heard of?

3 Categories of Environmental Problems

1. Resource Depletion

2. Pollution

3. Loss of Biodiversity

1. Resource Depletion

• Renewable resourceRenewable resource – a resource that is replaced by natural processes relatively fast

• Nonrenewable Nonrenewable resourceresource – a resource that is consumed much faster than it is replaced

Any natural material used by humans is called a natural resourcenatural resource

• A resource is depleteddepleted if a large fraction of the resource is used up much faster than it can be replaced

• Can nonrenewable resources be depleted?

• Can renewable resources be depleted?

2. Pollution

• PollutionPollution is an undesired change in air, water, or soil that adversely affects health, survival, or activities of humans, or other organisms

• Pollution happens when wastes are produced faster than be disposed of and accumulate in the environment

Biodegradable v. Non-biodegradable

• Pollutants that can be broken down in the environment are called biodegradablebiodegradable

• These become a problem when they accumulate faster than the environment can break them down

• Can you name some biodegradable pollutants?

Biodegradable v. Non-biodegradable

• Non-biodegradableNon-biodegradable pollutants are those that cannot be broken down easily or at all in the environment

• Because they do not break down it’s easy for them to build up to dangerous levels in the environment

• Can you name some non-biodegradable pollutants?

3. Loss of Biodiversity

• BiodiversityBiodiversity – the number and variety of species that live in an area

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

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

Loss of Biodiversity

• Only a fraction of the hundreds of millions species that have ever lived on earth are still alive – most are extinctextinct

• Extinction is a natural process – so why should people be concerned about modern extinction of species?

Sustainability

• SustainabilitySustainability - When human needs are met in such a way that a human population can survive indefinitely

• One of the key goals of environmental science is to achieve sustainability

“The Tragedy of the Commons”

• The main difficulty in solving environmental problems is the conflict between short-term interests of individuals and long-term welfare of society

• Someone has to take responsibility for maintaining a resource, or it will become overused and depleted.

Economic Pressures

• Law of Supply and DemandLaw of Supply and Demand – the greater the demand for a limited supply of something, the greater the worth

• Cost-Benefit AnalysisCost-Benefit Analysis – balances the cost of doing something with the benefits of not doing it

• Risk AssessmentRisk Assessment – determination of the risks of an undesirable outcome

Ecological Footprints

• An ecological footprint shows the productive area of Earth needed to support one person in a country

• It includes estimates for :– Land used for crops, grazing animals, forest

products, housing, waste storage– Ocean area for harvesting seafood– Forest area needed to absorb air pollution

Ecological Footprint Activity

• You will calculate your ecological footprint by taking a survey

• Survey will evaluate your usage in different categories (water, food, energy, etc.)

• Assign yourself points based on the answer choice that BEST matches your routine

• Add all points together and divide by 300 to get your ecological footprint

Exit Ticket

• List the three categories of environmental problems.  Give one example of each.