2. Quick recap What is albedo? What role does it have in helping to control climate? This February was the second coldest Winter on record in parts of the north east United States. How can climate change be real then?

3. Albedo Ability to reflect light – Ice reflects about 80% – Water absorbs about 80% Albedo increases during glacial periods and decreases when melting occurs.

4. Oceans Remove ~30% of excess CO 2 from atm. Increased CO 2 in the atmosphere means increased CO 2 in oceans. – Recall from earlier chapters this increases Carbonic Acid (H 2 CO 3 ) in oceans. Oceans have the ability to store and absorb heat in deep ocean – Delayed due to warming – Heat returns to atm and ends with warming temperatures.

5. Quick Recap People often confuse greenhouse gases, their association with climate change and ozone depletion. Discuss with your neighbor what each is and whether they are all connected or not.

7. Quick Recap Greenhouse effect – Greenhouse gases in the troposphere trap solar radiation (IR) heat in the troposphere. – WITHOUT TROPOSPHERIC COOLING EARTH WOULD BE ABOUT 0 O F AVERAGE Climate change – Alterations to climate patterns (precipitation, temperature, prolonged rainy/dry seasons) – Nonanthropogenic: Cyclic variation in temperatures and levels of atmospheric gases. – Anthropogenic Human activity (primary use of fossil fuels) is increasing concentration of GHG in the troposphere.

8. Greenhouse Gases Gas (time in ATM)SourceRelative Warming Potential CO 2 (50-120 yrs)Burning F.F. plant burning + deforestation 1 CH 4 (12-18 yrs)Natural leaks, cattle, coal23 N 2 O (114-120 yrs)Fertilizers, F.F, livestock waste, industry 296 CFC (11-20 yrs)Air conditioning/ refrigerator coolants, plastic foams 900-8300 HFC (10-400 yrs)“ 13-12700 HalonsFire Extinguishers5500 CCl 4 Cleaning Solvents1400 SF 6 Insulation + power lines23900 Ability to trap heat

9. Ways to measure changes in climate C-14 samples in ice and remains. Plankton and isotopes from ocean. Glacial ice cores – Sulfur dioxide and carbon samples Tree rings – Indicate dry/wet years – Cold vs warm Coral isotopes – C-14 in shells – Thickness of shells and CaCO 3 Historic records Temperature measurements.

11. How is carbon getting from reservoirs back into the atmosphere?

12. What has happened since the industrial revolution.

13. Potential impact of Climate change Flooding of coastal areas Glacial melt Ocean acidification Spread of infectious disease Droughts

14. Ways to reduce the impact..

15. Changes in transportation Increase CAFÉ standards – Increased MPG of cars

16. Changes in transportation Alternative fuels – Electric vehicles may only change nonpoint source to point source pollution – Fuel cells – Hybrids Catalytic converter – In cars to reduce amount of HC, CO and No x in atmosphere

17. Changes in Industry Electrostatic Precipitators and Scrubbers

19. Other ways to help Government taxes on carbon emission. Create cap and trade programs. Switch to cleaner energies Legislation International treaties

20. 1992 Earth Summit Rio de Janeiro 106 nations approved framework on Climate Change 2 principles: – Scientific uncertainty must no be used to avoid Precautionary Principle – Industrialized nations must take lead Reduction in GHG emission by 5.2 % below 1990 levels by 2000 GHG + CLIMATE CHANGE

21. 1992 Earth Summit 2 nd component was the Convention on Biological Diversity – As UN focused on preventing climate change they also focused on the prevention of global loss in biodiversity and prevention of species eradication

22. Kyoto Accord / Protocol Voluntary effort to reduce GHG emissions by 5.2% below 1990 levels by 2012 No requirements on developing countries Emission trading (carbon market) Clean development mechanism – Create reduction programs which offset emission credits Joint implementation – Transfer of credit of one country to another with emission reduction commitment by another GHG + CLIMATE CHANGE

23. The Ozone Hole

24. Seasonal thinning of Ozone Layer Ozone hole is over Antarctica Greatest depletion end of August- beginning of November

27. So how have we remedied the hole? Montreal Protocol – Treaty to cut CFC by 2000 – Also halt the production of CFC – Very effective and have seen a drastic increase of ozone within the stratosphere Copenhagen Protocol of 1992 – Phasing out of Ozone Depleting Compounds (ODC). – End all use of CFC by 1995 Halons by 1993 C-tetra- Cl by 1995 HCFC by 2020

28. Copenhagen Protocol of 1992 Amendment of Montreal to include… Phasing out of Ozone Depleting Compounds (ODC). End all use of – CFC by 1995 – Halons by 1993 – C-tetra- Cl by 1995 – HCFC by 2020