Science & The Environment

Section #1:Understanding Our

Environment

What exactly does the term ENVIRONMENT mean?

• includes everything around you• natural world• things produced by humans• more that just what can be seen by

the naked eye• complex web of relationships –

everything is connected to everything else

Discussion Question:• It is often

difficult for people to reach an agreement about environmental issues.

• Why?

What is Environmental Science?

• the study of how humans interact with the environment

• major goal = to understand & to solve environmental problems

• focus on how we use natural resources & how our actions alter our environment

Fields of Study• Biology – living organisms (zoology,

botany, microbiology, ecology)• Earth Science – nonliving systems

(geology, paleontology, climatology, hydrology)

• Physics – matter & energy (engineering)• Chemistry – chemicals & their

interactions (biochemistry, geochemistry)• Social Sciences – human populations

(geography, anthropology, sociology)

An Interdisciplinary Science

• One field plays a key role . . .

•Ecology – the study of how living things interact with each other and with their nonliving environment

How Have We Changed Our Environment Over Time?

How Have We Changed Our Environment Over Time?

• Hunter-Gatherers– small groups that migrated to find

food– burned prairies to maintain open

grasslands for some species– spread plants to other areas– over-hunting lead to disappearance

of some species (mass graves)

How Have We Changed Our Environment Over Time?

How Have We Changed Our Environment Over Time?

• Agricultural Revolution (10,000 yrs. ago)– stopped migrating, staying in one place– smaller areas could support greater

populations leading to rapid population growth

– saved seeds of the “good” plants, leading to the domestication of wild plants

– slash & burn destroyed habitats, leading to soil loss, flooding, water shortages

– over time the fields lost fertility

How Have We Changed Our Environment Over Time?

How Have We Changed Our Environment Over Time?

• Industrial Revolution (mid 1700s)– shift in animal power to fossil fuels– how did this change society?– how did this change the efficiency

of•agriculture•industry•transportation

Discussion Question:

•How have the things that make life easier also lead to more problems?

•What are some more recent problems we’re facing as technological advances continue?

What is a CLOSED system?

• Earth – it cannot get rid of used material nor can it take on new supplies

• What problems do you see on a – local scale?– regional scale?– global scale?

Compare the differences in population growth in the past 50 years. Why do

you think this is happening?

Population Growth

• being able to produce more food & transport that food to a sprawling nation has spurred a growth in the world’s population

• improvements to modern medicine & sanitation have also added in the survival rate

Graph – Population Growth

What are Our Main Environmental Problems?

•Resource Depletion

•Pollution

•Loss of Biodiversity

Resource Depletion

•Renewable vs. Nonrenewable•Any natural resource,

renewable or nonrenewable, can become depleted when a large fraction of the resource has been used up

Pollution

•An undesired change in air, water, or soil that adversely affects the health, survival, or activities of humans or other organisms

•Name some forms of pollution from human activites

2 Types of Pollutants

• Biodegradable = can be broken down by natural processes (ex. include human sewage & a stack of newpapers)

• Nondegradable = cannot be broken down by natural processes (ex. include mercury, lead, some types of plastic)

Loss of Biodiversity

• Extinctions, even mass extinctions, are a natural process & have occurred many times in Earth’s history

• Some scientists believe the rate of current extinctions is high & this may cause problems for humans down the road