1. Chapter 13: Climate Change & Ozone Loss

2. I. Climate Change A. The Greenhouse Effect is natural. B. Global Warming 1) Enhanced greenhouse effect due to human activity  Fossil fuel combustion, deforestation, etc. 1) First described by Swedish physicist/chemist, Svante Arrhenius in 1896

3. C. A little history… 1)Ice Core Samples: Gas trapped in ancient glaciers tested for air compositions *Increasing CO 2 levels correlate with: Rise in air temperature Increased fossil fuel use Deforestation

6. 2) Since 1861… Avg. global temperature has risen 1°F Sea level has increased 4-10 inches 1990’s and 2000- 2009= warmest decades (2012 = warmest year) 3) Other signs… Unusual weather patterns (ex. El Niño) Shrinking glaciers CO 2 levels higher than in last 420,000 years 20 th century was warmest in last 1,000 years

7. D. Main Greenhouse Gases: 1)CO 2 2)CH 4 3)N 2 O 4)CFCs (synthetic chlorofluorocarbon) 5)PFCs (synthetic perfluorocarbon) 6)SF 5 CF 3 (synthetic trifluoromethyl sulfur pentafluoride) Abundance GWP Global Warming Potential (GWP) describes a gas’ warming “strength” GWP of CO 2 = 1.0 (the standard) GWP of CH 4 = 21.0 In other words… CO 2 equivalent (CO 2 e)

8. Current Greenhouse Gas Emissions United StatesGlobal Source: IPCC (2007)IPCC (2007) Intergovernmental Panel on Climate Change

9. Source: IPCC (2007)IPCC (2007) Greenhouse Gas Emissions by Source Land Use, Land-Use Change, and Forestry in the United States is a net sink and offsets approximately 15% of these greenhouse gas emissions. United StatesGlobal

10. Greenhouse Gas Sources of Atmospheric Increase Carbon Dioxide (CO 2 ) Combustion (fossil fuels & plants) Deforestation Methane (CH 4 ) Agriculture (rice paddies, cows, etc.) Natural gas leaks Anaerobic decomposition (*landfills) Melting permafrost (positive feedback loop) Nitrous Oxide (N 2 ) Combustion of fossil fuels Fertilizers (& production of) Fluorinated Gases Refrigerants (AC’s, refrigerators, etc.) Industrial processes c c c c c c c c c c

11. Source: National CO2 Emissions from Fossil-Fuel Burning, Cement Manufacture, and Gas Flaring: 1751-2008.National CO2 Emissions from Fossil-Fuel Burning, Cement Manufacture, and Gas Flaring: 1751-2008. 2008 Global CO 2 Emissions from Fossil Fuel Combustion and some Industrial Processes (million metric tons of CO 2 )

12. Global Carbon Dioxide (CO2) emissions from fossil-fuels 1990-2008 Source of data: Boden, T.A., G. Marland, and R.J. Andres (2010). Global, Regional, and National Fossil-Fuel CO2 Emissions. Carbon Dioxide Information Analysis Center, Oak Ridge National Laboratory, U.S. Department of Energy, Oak Ridge, Tenn., U.S.A. doi 10.3334/CDIAC/00001_V2010.Boden, T.A., G. Marland, and R.J. Andres (2010). Global, Regional, and National Fossil-Fuel CO2 Emissions. Carbon Dioxide Information Analysis Center, Oak Ridge National Laboratory, U.S. Department of Energy, Oak Ridge, Tenn., U.S.A. doi 10.3334/CDIAC/00001_V2010.

13. Total U.S. Greenhouse Gas Emissions, 1990-2010 All emission estimates from the Inventory of U.S. Greenhouse Gas Emissions and Sinks: 1990- 2010.Inventory of U.S. Greenhouse Gas Emissions and Sinks: 1990- 2010.

14. E. Looking Towards the Future 1) Scientific Consensus: It’s time to change! (see p. 306)

15. Established in 1988 by World Meteorological Organization & the United Nations Environment Program Over 2,000 scientists from 195 countries

17. Signed 1997; first commitment 2008 Amendment 2012 Cooperating countries commit to reduce GHG emissions 2008-2012: 5% below 1990 levels 2013-2020: 18% below 1990 levels Mechanisms: International Emissions Trading Clean Development Mechanism Joint Implementation

18. Kyoto Protocol participation map (commitment period: 2013-2020) Parties; Annex I & II countries with binding targets Parties; Developing countries without binding targets States not Party to the Protocol Signatory country with no intention to ratify the treaty, with no binding targets Countries that have denounced the Protocol, with no binding targets Parties with no binding targets in the second period, which previously had targets

19. E. Looking Towards the Future 2) Reducing Greenhouse Warming (see p. 313-316) Higher energy efficiency Change/tighten government regulations on fossil fuels & emissions Alternate/renewable energy sources Harvest trees sustainably (sustainable yield) Carbon Dioxide Capture & Sequestration

21. Preparing for the effects of global warming…

22. Also… Use & engineer drought-resistant plants

26. II. Ozone Depletion (see p 321)

27. A. Summary of CFC/Ozone Reactions: CCl 3 F + UV Cl + CCl 2 F Cl + O 3 ClO + O 2 ClO + O Cl + O 2

28. Cl F F C C UV CFCl 3 O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O CFCl 2 O O O O O O O O ClO

29. B. Ozone Depleting Chemicals (ODCs) Include… 1) Chlorofluorocarbons (CFCs) a)Released from A/Cs, refrigerators, etc. b)Propellants (spray cans); the US banned use for this purpose in 1986 c)Produced while making/burning plastics d)Very persistent  65-385 years *Released by human activities since the 1950s

30. 2) Other ODCs: a)Halon: fire extinguishers

31. 2) Other ODCs: b) Methyl Bromide: pest fumigant

32. 2) Other ODCs: c) Carbon Tetrachloride (CCL 4 ): used to be in fire extinguishers and solvent

33. 2) Other ODCs: d) Methyl Chloroform/TCE (trichloroethene): dry cleaning solvent

34. 2) Other ODCs: e) HCl: released by space shuttles Good thing we cancelled the program!

35. C. Seasonal Ozone Thinning 1) Thinning is most severe over the poles *Greatest over Antarctica

37. 2) Why seasonal? Polar Winter: No direct solar radiation Chlorine (from CFCs) trapped in the polar vortex Polar Spring: Direct solar radiation Cl released & reacts with ozone 40%-50% ozone loss Polar Summer: Vortex weakens CFCs & Cl disperse Ozone rebuilds

40. Which month?

42. D. Effects on Human Health 1)More sun burns …I was in the Bahamaaas! 2)Eye Cataracts 3)Immune System Suppression 4)Skin Cancer (p. 321)

43. a) Squamous Cell Carcinoma Upper epidermis Least dangerous but can metastasize

44. b) Basal Cell Carcinoma Most common Curable if treated early

45. c) Melanoma Cancerous melanocytes (pigment cells) Metastasizes quickly Most deadly (kills ¼ of victims) *Mostly caused by UV-A

47. E. Environmental Effects 1)Reduced crop yield (up to $2.5 billion loss/year!) 2)Reduced forest productivity 3)Reduced phytoplankton productivity Increased UV exposure

48. F. Solutions 1)Substitutions for CFCs a)HCFCs: less reactive/persistent b)HFCs: non-reactive with ozone *DuPont took 14 years to change production!

49. 2) Montreal Protocol (1987 – present) a)Goal: Reduce ODC emissions/find alternatives b)All UN recognized nations have ratified the treaty