How much should it How much should it cost?cost?

Rank the following items in order of Rank the following items in order of their importance to you. Then, next their importance to you. Then, next to each item, write down how much to each item, write down how much you would be willing to pay for it.you would be willing to pay for it.

Fresh, clean drinking waterFresh, clean drinking water Clean air to breatheClean air to breathe An endangered plant containing a An endangered plant containing a

substance that can cure cancersubstance that can cure cancer Gas for your family carGas for your family car

What Is What Is Environmental Environmental

Science?Science?What do you think this class What do you think this class

will be about? will be about?

What will you learn?What will you learn?

What do you What do you wantwant to learn? to learn?

Environmental ScienceEnvironmental Science The study of how we and other species interact The study of how we and other species interact

with one another & with the nonliving with one another & with the nonliving environment (matter & energy)environment (matter & energy)

Includes:Includes: Physics, chemistry, biology, ecology, geology, Physics, chemistry, biology, ecology, geology,

meteorology, geography, resource technology, meteorology, geography, resource technology, engineering, resource conservation & engineering, resource conservation & management, demography, economics, politics, management, demography, economics, politics, sociology, psychology, ethicssociology, psychology, ethics

The environment The environment is difficult!is difficult!

The environment is difficult to study The environment is difficult to study because…because…

A hypothesis must be testableA hypothesis must be testable

VARIABLES must be controlled and isolatedVARIABLES must be controlled and isolated Too many interactions – known & unknownToo many interactions – known & unknown

More problemsMore problems

Scale is often a problemScale is often a problem Populations over timePopulations over time Environmental factors over centuriesEnvironmental factors over centuries

Measurement is difficultMeasurement is difficult Species, pollutants, tons of soilSpecies, pollutants, tons of soil

We do our best…We do our best… At best, we provide trends & estimatesAt best, we provide trends & estimates

Rely on models Rely on models

CorrelationsCorrelations Example: BPA findings (1:34) Example: BPA findings (1:34)

http://www.npr.org/templates/story/story.php?storyId=94699105http://www.npr.org/templates/story/story.php?storyId=94699105

ModelsModels

A representation or simulation of a A representation or simulation of a system being studiedsystem being studied

Can be mental, physical, graphical, Can be mental, physical, graphical, mathematical, conceptualmathematical, conceptual

CorrelationCorrelation Relationship between two separate Relationship between two separate

eventsevents More CO2 and higher global More CO2 and higher global

temperaturestemperatures

Correlation DOES NOT Correlation DOES NOT mean causation…mean causation…

More lemons imported causes more traffic More lemons imported causes more traffic accidents?accidents?

SYSTEMS & FEEDBACK LOOPS

System Vocabulary• INPUT

matter, energy, information entering a system

• THROUGHPUT rate flow of matter, energy, or information

through a system

• OUTPUT matter, energy, information leaving a system

Stuff goes inStuff is

processedStuff comes

out

Input Throughput Output

FEEDBACK LOOPS

Change induces change

Stuff goes inStuff is

processedStuff comes

out

Feedback Loop

Negative Feedback Loops

• The change counteracts the situation

Examples:

What happens when you’re hot?

What happens when you’re cold?

Positive feedback Loops

• The change compounds the situation = Snowball Effect!

Example:

As long as there are more human births than deaths, population will continue to

increase.

Pesticides:

Urban Sprawl

Positive or Negative

• 1 person in a group of 10 has cold.

• That person passed the cold to another and soon 5 people now have the cold.

• Those 5 students then each pass the cold to another.

Feedback Loops in Context

Global warming hypothesizes that the average temperature of Earth is increasing. During analysis, scientists have identified possible positive and negative feedback loops to explain atmospheric climate change.

• http://science.howstuffworks.com/global-warming.htm

Radiation and Reflection

Positive or Negative?

• The warming of the oceans causes

dissolved CO2 to bubble out into the

atmosphere. This atmospheric CO2 helps

to trap heat near the earth. This trapped

heat continues to warm the ocean.

Positive or Negative?

• Warmer water temperatures cause greater

water evaporation, which increases the

formations of clouds. A lot of water vapor

in the air also traps heat inside the

atmosphere.

Positive or Negative?

• The increased cloud cover from example 2

might also act to reflect sunlight back into

space, preventing it from entering our

atmosphere. This might cool the earth.

Positive or Negative?

• Sunlight striking the earth is absorbed by

dark colors and reflected by light colors.

The polar ice caps act like huge mirrors,

reflecting sunlight back into space.

Warmer water temperatures are melting

these ice caps and decreasing these big

“mirrors,” leaving dark water behind.

Positive or Negative?

• Warmer temperatures cause greater water

evaporation, which falls to earth as

precipitation. Therefore global warming

may cause increased snow fall in the polar

regions, leading to increased ice

formation.

How did you do?

• 1. Positive

• 2. Positive

• 3. Negative

• 4. Positive

• 5. Negative

Contemplate this…• What would Earth look like if there weren't

any greenhouse effect at all?

• It would probably look a lot like Mars.

• Mars doesn't have a thick enough atmosphere to reflect enough heat back to the planet, so it gets very cold there.

Hmmmmm….• Some scientists have suggested that we

could terraform the surface of Mars by sending "factories" that would spew water vapor and carbon dioxide into the air.

• If enough material could be generated, the atmosphere might start to thicken enough to retain more heat and allow plants to live on the surface.

Just like early Earth…• Once plants spread across Mars, they

would start producing oxygen.

• After a few hundred or thousand years, Mars might actually have an environment that humans could simply walk around in

-- all thanks to the greenhouse effect.