*Unit 9

Question 1

Where are the locations for ozone in the atmosphere?

Answer 1

Troposphere (ozone from photochemical smog, causing the greenhouse effect) and Stratosphere (naturally-occurring ozone that provides protection from UVB/UVC rays)

Question 2

What does stratospheric ozone do?

Answer 2

It prevents radiation (UVB/UVC) from reaching the earth

Question 3

What is the antarctic spring exception for stratospheric ozone?

Answer 3

Antarctic winters create stratospheric ice crystals that contribute to ozone degradation, thinning the ozone layer there.

Question 4

What is the use of chlorofluorocarbons?

Answer 4

• Refrigerant/coolant
• Propellant
• Some types of plastics

Question 5

How do CFCs contribute to stratospheric ozone depletion?

Answer 5

UV light can remove chlorine from CFCs, and the free chlorine catalyzes the conversion of O3 to O2.

Question 6

Why is stratospheric ozone depletion bad?

Answer 6

If the ozone is converted to atmospheric oxygen, then it is not keeping out harmful UVB and UVC rays. This disrupts the process of terrestrial photosynthesis and photosynthesis by phytoplankton. This then disrupts food chains/webs and impacts populations of organisms like amphibians. Additionally, long term exposure to UV light can result in skin cancer and cataracts.

Question 7

How do we reduce stratospheric ozone depletion?

Answer 7

• Montreal Protocol: International treaty which began to phase out the use of chlorofluorocarbons and their manufacture
• Hydrofluorocarbons to replace chlorofluorocarbons (while there are many advantages to this, HFCs are a powerful greenhouse gas)

Question 8

Where does the greenhouse effect occur?

Answer 8

Troposphere

Question 9

What is the greenhouse effect?

Answer 9

1. Solar radiation warms the earth
2. Some energy is reflected, some energy is re-radiated as heat back into space
3. Some re-radiated heat is absorbed by greenhouse gases in the troposphere, then emitted again toward the surface of the Earth as heat

Question 10

What are the different types of greenhouse gases?

Answer 10

• Carbon Dioxide (CO2)
• Methane (CH4)
• Water Vapor (H2O)
• Nitrous Oxide (N2O)
• Chlorofluorocarbons (CF2Cl2 there are other types)
• Hydrofluorocarbons (HCF3)
• Tropospheric ozone (O3)

Question 11

Where does the majority of CO2 emissions come from?

Answer 11

Transportation and electricity

Question 12

Where does the majority of CH4 emissions come from?

Answer 12

Enteric Fermentation, Natural Gas and Petroleum Systems, and Landfills