AIR POLLUTION AND OZONE LOSS - A Chapter 19

AIR POLLUTION AND OZONE DEPLETION CHAPTER 19

This unit is entirely based on Chapter 19 of your textbook. It covers all of Unit 6 and part of Unit 9 from the AP curriculum.

•  6.1 – Introduction to Air Pollution

•  6.2 – Photochemical Smog

•  6.3 – Thermal Inversion

•  6.4 – Atmospheric CO2 and Particulates

•  6.5 – Indoor Air Pollutants

•  6.6 – Reduction of Air Pollutants

•  6.7 – Acid Rain

•  6.8 – Noise Pollution

•  9.1 – Stratospheric Ozone Depletion

•  9.2 – Reducing Ozone Depletion

9.1 – STRATOSPHERIC OZONE

UNEP/WMO, 2006: Fig. Q1-2

OZONE IN THE ATMOSPHERE

•  Stratosphere – Good Ozone – Blocks UV radiation – Hole caused by depletion

due to CFC’s •  Troposphere – Bad Ozone

– Pollution •  Photochemical smog •  Eye irritant

UNEP/WMO, 2006: Fig. Q2-1

HOW IS OZONE FORMED? • Ozone forms a

layer in the stratosphere, thinnest in the tropics (around the equator) and denser towards the poles.

GOOD OZONE

6

NATURAL VARIATIONS OF TOTAL OZONE

•  Fall •  Highest at mid- and high

latitudes

•  Winter and spring •  Lowest in polar regions

(due to movement of chlorine and bromine)

•  Year round •  Low in the tropics (less

dense)

SEASONAL VARIATION

• Ozone thinning (hole) occurs each winter in the Arctic and Antarctica

• Polar vortex traps CFCs over polar regions

WHY WORRY ABOUT OZONE HOLES?

•  Increase health issues •  Sunburns •  Skin cancer •  Cataracts •  Immune system

suppression

•  Environmental Issues •  Lower productivity

OZONE DEPLETION CULPRITS

• CFCs • Other culprits

•  Halons and HBFCs from fire extinguishers

•  Methyl bromide, a fumigant

•  Hydrogen chloride from space shuttles

OZO

NE

DEP

LETI

ON

One CFC molecule removes 100,000 Ozone molecules

9.2 – REDUCING OZONE DEPLETION

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SOLUTION: MONTREAL PROTOCOL 1989

•  An international treaty designed to protect the ozone layer –  phasing out production of number

of substances believed to be responsible for ozone depletion

UNEP/WMO, 2006: Fig. Q15-1

OZONE AND GLOBAL WARMING

Ozone Depletion

•  Loss of O3 in stratosphere

•  Increased UV radiation to Earth’s surface

•  CFCs, HBFCs, Bromines

•  Decreased productivity due to ‘frying’ of photosystems

•  Increased skin cancer and cataracts

•  SUCCESS – Montreal Protocol

Global warming •  Accumulation of GHGs in troposphere

•  Increased trapping of IR radiation in Earth’s troposphere

•  CO2, CH4, N2O, H2O, CFCs, O3

•  Decreased productivity due to shifts in temperature and precipitation

•  Climate shifts

•  Increased tropical diseases

•  No successful policy to date – Kyoto Protocol

UNEP/WMO, 2006: Fig. Q18-1

OZONE ANIMATIONS

•  What is ozone? •  How is ozone destroyed?