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Topics for Today What can we do about the ozone hole (Part 1)? Quiz #6!!

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Presentation on theme: "Topics for Today What can we do about the ozone hole (Part 1)? Quiz #6!!"— Presentation transcript:

1 Topics for Today What can we do about the ozone hole (Part 1)? Quiz #6!!

2 Readings for Today Just review sections 2.11 and 2.12

3 Topics for Monday Where did my gasoline come from? Burning a gallon of gasoline…

4 Readings for Monday 3.6 Quantitative Concepts: Mass 3.7 Quantitative Concepts: Molecules and Moles

5 Announcements!!

6 Announcements!!

7 Announcements!! Exam #2 next Friday (the 16 th ) Same deal as last time… Non- memory calculators OK. Please sit in dark seats Exams will be handed out at the door (at 8:35) Periodic Table will be attached…

8 Topics for Today What can we do about the ozone hole (or, what have we done)? Quiz #6!!

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10 1974 Rowland and Molina report CFC damage to the ozone layer. Both won the Nobel Prize (Chemistry) in 1995)

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12 The ozone layer can only return to its 1970s status if all nations join in the effort to eliminate the emission of ozone- depleting substances into the atmosphere. Failure to ratify the ozone treaties may hinder international efforts to protect the earth from the damage caused by ozone- layer depletion. While such damage will have a global impact, developing countries are likely to be the most severely affected. party%20montreal%20protocol.shtml

13 Help!

14 Early 1970s… The US decided that ozone depletion is a national problem.

15 Early 1970s… The US decided that ozone depletion is a national problem. Banned the use of “non-essential” CFCs in 1978.

16 Uses of CFCs Propellants!

17 Early 1970s… Banned the use of “non-essential” CFCs in A few countries joined in (Canada and Sweden), but this was still NOT an international issue.

18 The Vienna Convention 1985 “The International community legitimized stratospheric ozone depletion as an international issue.” PETER M. MORRISETTE – Columbia college

19 Montreal Protocol 1987 International Meeting (24 countries attended)! Agreed to work together to limit CFC use and emissions We won’t go into the details here…

20 By 1989, 36 countries ratified the Protocol What exactly did the Protocol call for?

21 By 1989, 36 countries ratified the protocol How many countries have ratified it today?

22 By 1989, 36 countries ratified the protocol "Perhaps the single most successful international agreement to date...". Kofi Annan For the developed countries, the protocol stipulates that the production and consumption of Group I compounds are to be frozen at 1986 levels beginning in Production and consumption of Group I compounds must be reduced to 80 percent of 1986 levels by 1994, and 50 percent of 1986 levels by 1999.

23 “At present, 191 nations have become party to the Montreal Protocol. Those 5 that are not as of November 2006 are Andorra, Iraq, San Marino, Timor-Leste and Vatican City.”

24 4/7/06 - Fiji To Sign And Ratify Amendments to the Montreal Protocol

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28 One reason that the Montreal Protocol was so successful…

29 1985 Vienna 1987 Montreal 1990 London 1992 Copenhagen 1995 Vienna 1997 Montreal 1999 Beijing 2003 Nairobi 2004 Prague 2005 Dakar, Senegal PERSISTANCE!!

30 The Montreal Protocol on Substances that Deplete the Ozone Layer as adjusted and/or amended in London 1990 Copenhagen 1992 Vienna 1995 Montreal 1997 Beijing 1999 UNEP Ozone Secretariat United Nations Environment Programme The details (FYI)

31 As of 19 February 2007, the status of ratification is as follows: Ratification of: Vienna Conventi on Montreal Protocol London Amendm ent Copenhagen Amendment Montreal Amendme nt Beijing Amendm ent Total number of countries Accessed March 7, 2007

32 Has the Montreal Protocol been successful?

33 "Perhaps the single most successful international agreement to date...". Kofi Annan

34 Has the Montreal Protocol been successful? "Perhaps the single most successful international agreement to date...". Kofi Annan Let’s look at the data…

35 A paper on the subject involving researchers from CU-Boulder, NOAA, the University of Wisconsin Madison, the University of Chicago and the University of Illinois the team documented a leveling off of declining ozone levels between 1996 and 2002, and even measured small increases in some regions.

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37 Alternatives! Another reason the Montreal Protocol was so effective?

38 CFCs are bad for 2 reasons 1) Make their way up to the stratosphere 2) Contain Cl First replacement…

39 Uses of CFCs Foaming Agents! Styrofoam® C = C H HH Styrene 6

40 Uses of CFCs Refrigerants!

41 CFC-12 (dichlorodifluoromethane) C Cl F F C H F F HCFC-22 chlorodifluoromethane OR C C F F Cl H H H HCFC-142a 1-chloro-1,1-difluoroethane

42 Why HCFCs?

43 H Cl H Cl | | | | H – C – C – Cl H – C – C – Cl | | | | H F HCFC-141b H F HCFC-141b1,1-chloro-1-fluoroethane HCFCs (hydrochlorofluorocarbons) Atmospheric life-time of about 10 years! Why is this so different from CFCs?

44 H Cl H Cl | | | | H – C – C – Cl H – C – C – Cl | | | | H F HCFC-141b H F HCFC-141b1,1-chloro-1-fluoroethane HCFCs (hydrochlorofluorocarbons) Results in lower ability to deplete ozone

45 What are the problems with HCFCs?

46 1) Rapidly Increasing

47 CFCs are bad for 2 reasons 1) Make their way up to the stratosphere 2) Contain Cl

48 2) Still deplete ozone WHY? Contain Cl!

49 Alternatives to the alternative?

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51 HFCs (hydrofluorocarbons) F F F F | | | | H –– C –– C –– F H –– C –– C –– F | | | | H F H F R-134a What is the name of this molecule?

52 HFCs (hydrofluorocarbons) F F F F | | | | H –– C –– C –– F H –– C –– C –– F | | | | H F H F R-134a What is the name of this molecule? 1,1,1,2-tetrafluoroethane

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54 HFCs Contain no Cl Do not deplete ozone

55 HFCs Contain no Cl Do not deplete ozone Problems with HFCs?

56 HFCs Contain no Cl Do not deplete ozone Problems with HFCs? They are extremely potent greenhouse gases (stay tuned)!

57 Any other alternatives?

58 O=C=O O::OC::.. carbon dioxide!!

59 “Researchers are making progress in perfecting automotive and portable air-conditioning systems that use environmentally friendly carbon dioxide as a refrigerant instead of conventional, synthetic global- warming and ozone-depleting chemicals.”

60 Why CO 2 ? Easy to get… It is in the atmosphere already It does not deplete ozone

61 “Toyota Motor Corporation a claimed world- first non-fluorocarbon car air conditioner using natural refrigerant, carbon dioxide (CO 2 ).” Dec 2002

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63 END EXAM #2


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