The OZONE!!The OZONE!!By: The Green Squirrels

Names of Team Members

April 20,2005

Goals of this presentationGoals of this presentation

• Inform you of the ozone depletion of course!!– Background and History– Chemical Principles – Some Facts – HOW IT AFFECTS YOU!

Why Should You Know about the Ozone….

Why Should You Know about the Ozone….

• YOU…yes you…are one of the main factors in what is causing ozone depletion

• Because of ozone depletion you are susceptible to diseases such as cataracts, malignant melanoma, etc.

• Ozone depletion affects you and the world we live in

Location, Location, LocationLocation, Location, Location

• The Ozone (O3) all around us

• 90% of the Ozone is contained in the stratosphere approx. 15 to 50 km above the earth

STRATOSPHERIC OZONESTRATOSPHERIC OZONE

What is this Ozone that I speak of?What is this Ozone that I speak of?

• Studies of the upper atmosphere dates back to the 1800’s!

• 1930 – Sidney Chapman

• Multiple studies before 1970 do not take into account humans

• Click Me

What The Ozone DoesWhat The Ozone Does

• Earth’s Natural Sunscreen

• UV-A: relatively harmless; causes tanning not burning

• UV-B: harmful; causes sunburn, skin cancer, and other disorders

• UV-C: extremely harmful; but almost completely absorbed by ozone

Causes Of Ozone DepletionCauses Of Ozone Depletion

• Chlorofluorocarbons: refrigerants, solvents, foam blowing agents

• Methyl Chloroform: solvent

• Carbon Tetrachloride: industrial chemical

• Halons: fire extinguishing agents

• Methyl bromide: produce and soil fumigant

all uv-c and most uv-b never reaches the Earth’s surface

Ozone (O3) is a molecule made up of three atoms of oxygen (O)

high energy ultraviolet light = UV-C

O2 + UV-C photon —› O + O

O + O2 —› O3 (ozone)

O3 + UV-B photon —› O + O2

O + O3 —› O2 + O2

O2 + UV-C photon —› O + O

O + O2 —› O3 (ozone)

O3 + UV-B photon —› O + O2

O + O3 —› O2 + O2

CHAPMAN CYCLECHAPMAN CYCLE

Causes Of Ozone DepletionCauses Of Ozone Depletion

• Chlorofluorocarbons: refrigerants, solvents, foam blowing agents

• Methyl Chloroform: solvent

• Carbon Tetrachloride: industrial chemical

• Halons: fire extinguishing agents

• Methyl bromide: produce and soil fumigant

PROS and CONS of Ozone DepletionPROS and CONS of Ozone DepletionPROS

• There are no positives to ozone depletion.

CONS• Less plant production• Less frogs and

amphibians• Increase of skin cancer

and cataracts in humans

Ozone Depletion Since 1980Ozone Depletion Since 1980

Affects on Human HealthAffects on Human Health

Ultra Violet – B radiation damages human skin

• Non-melanoma skin Cancer

• Cataracts

The Antarctic Ozone HoleThe Antarctic Ozone Hole

• Ozone levels have dropped 33% since 1975

• Most depletion happens from September to December

• 3 – 5 degree increase in temperature predicted for 2020

Where did all this info come from??

Where did all this info come from??

• Barid, Colin, Wendy Gloffke. Chemistry in Your Life. W.H. Freeman 2003. New York

• CIESIN Thematic Guides: Ozone Depletion and Global Environmental Change– http://www.ciesin.org/TG/OZ/oz-home.html

• Hardy, John T., Climate Change Causes, Effects, and Solutions. John Wiley & Sons 2003. West Sussex, England.

• Miller, Tyler. Environmental Science. Thompson Brook/Cole. 2004. California

• http://www.ozonediw.org• The Ozone Hole

– http://www.theozonehole.com/ozonecreation.htm• U.S. EPA: Ozone Depletion Science

– http://www.epa.gov/ozone/science/index.html