6.2 stratospheric ozone

Question 1

formation of ozone

Answer 1

• uv radiation splits oxygen molecule into two oxygen atoms
• oxygen atom reacts with oxygen molecule to form ozone
• ozone is lost by a reaction with other ozone molecule, oxygen atom or trace gas
• converts UV radiation into thermal energy, heating the stratosphere
• dynamic equilibrium

Question 2

impacts of stratospheric ozone

Answer 2

• lets in all UVA, longest wavelength
• some UVB, mid wavelength
• no UVC, shortest wavelength

Question 3

UVB causes

Answer 3

• sunburn, premature aging
• skin cancer
• cataracts
• immune- suppression
• health problems
• reduction in crop production
• reduced phytoplankton growth
• reduction in forest productivity

Question 4

chlorofluorocarbons
CFCs

Answer 4

• ozone depleting substance (ODS)
• long lifetimes
• widely used in coolants, propellants in aerosol, cleaning, polystyrene
• can’t dissipate in the air, not soluble

stratosphere
- UV breaks down CFC molecule producing chlorine atoms
- chlorine atoms react with ozone breaking it down
- destroys ozone equilibrium, ozone depletion
- one molecule CFC destroy 100,00 molecules of ozone

Question 5

ADD 6.2 CHANGES IN STRATOSPHERIC OZONE LEVELS

Answer 5

ADD 6.2 CHANGES IN STRATOSPHERIC OZONE LEVELS

Question 6

montreal protocol

Answer 6

• remove production and consumption of ODS
• legally binding
• reduce production of CFCs
• assist developing countries
• effective in banning CFCs, decreasing concentration in the atmosphere, some increasing - illegal, others not fully phased out
• continually reviewed and changed to be effective
• successful international cooperation

Question 7

challenges with ODS’s

Answer 7

• long lifespan
• present in discarded equipment
• lack of alternatives
• replacement chemical (HCFC) also ODS, shorter life span, GHGs
• illegal trade of ODSs
• lack of enforcement

Question 8

pollution management of ODSs
altering human activity

Answer 8

• education campaign, stop buying ODS
• replacements

Question 9

pollution management of ODSs
controlling release of pollutant

Answer 9

• banning production and use
• policing and enforcement to ensure compliance, stop illegal use

Question 10

pollution management of ODSs
clean up and restoration

Answer 10

• removal and destruction of existing ODSs in products