Earth 2

Tuesday, April 27th, 1999
Announcements: The final exam is scheduled for Monday, May 3. The exam concentrates mostly on the last 1/3 of the notes, however, it is cumulative.

Lecture notes:

Global Warming

Driver: the combustion of fossil fuels and deforestation. Human subset also produces CFC's, nitrous oxides, and methane.

Issue: gases are selective absorbers

Result: some form of global warming

Future: can be seen through 1) Observations 2) Models

Response: (these all help to make decisions)

• Winners & Losers
• Uplacement (for driver)?
• Economics
• Valuation (of environment)

Action: ?

Stratospheric Ozone

Driver: propelant; solvent; air conditioning

Issue: chloroflourocarbons (from the air conditioning)

Result: stratospheric ozone depletion...ending up with a loose chlorine atom acting as a catalyst

Future: Destructed ozone "shield" will promote skin cancer, gene mutations, depression of immune systems, etc.

Response:

• Limit ozone depleting chemicals (through treaty's)
• Losers (no one wants those things)
• Replacement was easy (it was simple to switch over)
• No questions about the future

Action: It was taken immediately, and actually served the problem

Deforestation

Driver: economic growth for specific luumber products, farms, cattle ranches, developing countries

Issue: land cover change

Result: nutrient loss, precipitation loss, erosion, loss of biodiversity

Future:

• Substantial depletion of forests
• Will have a global effect
• CO2 increases from tropical rain forest combustion
• Circulation changes

Response:

• Dealing with nations
• Economics are substantial
• Valuation of Species
• Future perceptions are uncertain

Nuclear War

Driver: Energy...Weapons

Issue: Inexpensive energy...potent weapons

• DANGER--Reactors, Waste
• WAR--Nuclear Winter

Result: Weak energy industry, accumulated waste over 100,000 years

Future: ? (difficult to predict on a 100,000 year time scale)

Response: ?

Action:

• Clear Threat
• No winners
• Technology Ready

Little Action:

• Technology not ready
• Winners & Losers
• Future is uncertain
• Valuation

Future

1) Continue

2) Managed Earth

3) Managed Humans