Unit 6.2 Stratospheric ozone

Question 1

What is Ozone

Answer 1

molecule made up of three oxygen atoms (O3)

Question 2

Where is Ozone found

Answer 2

highest concentration of ozone occurs in the so-called ozone layer, in the lower stratosphere.

Question 3

Ozone layer

Answer 3

The highest concentration of ozone occurs in the so-called ozone layer, in the lower stratosphere.

Question 4

Importance of Ozone layer

Answer 4

Stratospheric ozone is a key component of the atmospheric system because it protects living systems by blocking incoming ultraviolet (UV) radiation from the Sun.

Question 5

Ozone depletion substance (ODS)

Answer 5

1. Chlorofluorocarbons (CFCs) and HCFCs (persist 100 years after)
2. Methyl bromide
3. Nitrogen oxides (NOx)

Used in aerosols, gas-blown plastics, pesticides, flame retardants and refrigerants.

Question 6

Human activities that lead to ozone depletion

Answer 6

refrigeration
air conditioning
aerosol propellants

Question 7

Ozone depletion and climate change

Answer 7

1. absorbs solar ultraviolet radiation, which heats the stratosphere.
2. absorbs infrared radiation emitted by the Earth’s surface, trapping heat in the troposphere

Question 8

Ozone depletion

Answer 8

The result of air pollution by chemicals that are mostly human-made.

Question 9

Management strategies for ODS

Answer 9

Replace:
1. gas blown plastics
2. CFCs with carbon dioxide
3. aerosoles with pump actions
4. methyl bromide pesticides

Regulate:
1. recover and recycle CFCs from refrigerators and AC units
2. Legislate to have fridges returned to the manufacturer and coolants removed and stored
3. Capture CFCs from scrap car air conditioner units

Restoration:
1. Add ozone (not practical)

Question 10

The Montreal Protocol

Answer 10

Global/international agreement to protect the Earth’s ozone layer by phasing out the production and consumption of ODS

Signed in 1987 in Montreal (Canada). Came into effect in 1989

197 countries have ratified

Question 11

Success of the Montreal Protocol

Answer 11

1. Universal participation on 16 September 2009
2. Strong industry cooperation
3. Strong civic engagement
4. First protocol to recognize different countries could phase out chemicals at different times
5. Funding

Question 12

Effects of increased exposure of UV

Answer 12

1. Genetic mutation
2. Damage to living tissues
3. Cataract formation in eyes
4. Skin cancers
5. Suppression of the immune system
6. Damage to photosynthetic organisms (phytoplankton)
7. Damage to consumers of photosynthetic organisms (zooplankton