ECOL 1000 Ecological Basis of Environmental Issues University of Georgia Spring 2015 Lecture 6 Air Quality Ozone Ozone trioxygen Molecule consisting of three atoms Ozone in lower atmosphere is a pollutant Ozone in the upper atmosphere is beneficial Ozone layer Highest levels of ozone are in the stratosphere Ozone filters out Sun s UV light rays which are harmful but also used for production of vit D Ozone is produced naturally from UV rays reacting with O2 CFC Production Invention of chlorofluorocarbons CFCs in the 1920s Safer alternative to the sulfur dioxide and ammonia refrigerants used at the time Chlorofluorocarbons were chosen for safety and for their advantageous chemical properties low in toxicity nonflammable noncorrosive and nonreactive with other chemical species and have desirable thermal conductivity and boiling point characteristics Principal uses of CFCs coolants in refrigeration systems and air conditioners solvents to clean electronic components blowing agents in the production of plastic foams and propellants in air conditioners CFC uses Of the 682 000 000 kg of chlorofluorocarbons consumed globally during 1991 DuPont Co estimated the use for various applications 32 for refrigerants 28 for blowing agents 20 for cleaning agents 18 for propellants CFC Consumption Worldwide CFC s CFC s are are light light and and float float up up into into the the stratosphere stratosphere 3 3 loss loss of of ozone ozone You You are are here here Ozone Ozone absorbs absorbs UV UV light light CFC s CFC s destroy destroy ozone ozone therefore therefore CFC s CFC s permit permit increased increased UV UV radiation radiation Increased Increased UV UV radiation radiation is is hazardous hazardous to to your your health health Through Through their their influence influence on on UV UV CFC s CFC s are are secondarily secondarily hazardous hazardous to to your your health health Frank Sherwood Rowland video The 1987 Montreal Protocol International treaty created to reduce the damage being caused to the stratospheric ozone layer by air pollutants such as refrigerant gases Under the Protocol production and use of substances that have been identified to deplete the ozone layer were to be be phased out by 2000 All United Nations member states have approved Montreal Protocol It is expected that the ozone layer will recover by 2050 Perhaps the single most successful international agreement to date has been the Montreal Protocol Kofi Annan Industrialized countries have reduced ozone emmisions Stratosphere Stratosphere Ozone Ozone is is good good Ozone Ozone is is bad bad Troposphere Troposphere Atlanta s ozone smog Hydrocarbons Hydrocarbons NO NOxxUV UV Light Light O O33 Ozone Ozone in in the the lower lower atmosphere atmosphere is hazardous is hazardous to to your your health health NO NOxx is is produced produced by by automobile automobile exhaust exhaust Hydrocarbons Hydrocarbons are are produced produced by by Automobile Automobile exhaust exhaust Trees Trees e g e g turpentine turpentine Hyrdocarbons Hyrdocarbons and and nitrous nitrous oxide oxide are are heavy heavy and and sink sink to to ground ground level level Nitrous Nitrous Oxide Oxide Increasing Increasingrisk riskof of Asthma Asthma Bronchitis Bronchitis Heart Heartattack attack Etc Etc Increased Increasedrisk riskof ofdying dyingfrom fromlung lungdisease diseaseof ofover over30 30 in in cities citieswith withhigh highozone ozonelevels levels Atmospheric Atmospheric Ozone Ozone Ozone Change Stratospher e 7 miles Troposphere 7 miles Destroyed by CFC s Biological Effects UV Penetration Trend improvi ng Atmospheric Atmospheric Ozone Ozone Ozone Change Stratospher e 7 miles Destroyed by CFC s Created Troposphere by NOx and 7 miles hydrocarbon s Biological Effects Trend UV Penetration improvi ng Irritation of eyes respiratory systems etc worseni ng Brief BriefHistory Historyof ofOzone Ozone 1970 1970 CFC s detected in the air CFC s detected in the air 1974 1974 Rowland warns of harmful effects Rowland warns of harmful effects 1978 1978 U S bans CFC production U S bans CFC production Dupont begins research on alternatives Dupont begins research on alternatives 1980 1980 Reagan discredits facts Reagan discredits facts Brief BriefHistory Historyof ofOzone Ozone 1981 1981 DuPont stops research on alternatives DuPont stops research on alternatives 1982 1982 DuPont states CFC production will not increase but global production actually doubles to 1 1 metric tons yr DuPont states CFC production will not increase but global production actually doubles to 1 1 metric tons yr DuPont discredits facts DuPont discredits facts 1985 1985 Rowland s numbers verified Rowland s numbers verified Hole in the ozone proven Hole in the ozone proven 1986 1986 DuPont seeks alternatives DuPont seeks alternatives Brief BriefHistory Historyof ofOzone Ozone 1987 1987 Montreal Protocol Signed Montreal Protocol Signed Compromise CFC production reduced by 50 by 1998 Compromise CFC production reduced by 50 by 1998 1990 1990 Montreal Protocol updated Montreal Protocol updated Total elimination by the year 2000 Total elimination by the year 2000 1992 1992 DuPont researches alternatives DuPont researches alternatives 1993 1993 DuPont announces chlorine free coolant DuPont announces chlorine free coolant Brief Brief History History of of Ozone Ozone 1997 1997 Rowland Rowland wins wins Nobel Nobel Prize Prize What What to to do do Get an annual pollution control check up for your car Buy fuel efficient cars Use creams in tubes not propellant foams in cans Use paper cups not styrofoam cups Use washable not dry clean only clothing