The document summarizes key concepts about climate change and the ozone layer. It discusses how human activities like burning fossil fuels and deforestation have increased greenhouse gas levels and global temperatures over the past century. It also explains how certain chemicals released into the atmosphere deplete the stratospheric ozone layer, increasing health and environmental risks. A variety of international efforts aim to reduce emissions and protect the ozone.

1. Shohail Motahir Choudhury G. Tyler Miller’s Living in the Environment 14th Edition Chapter 21 Climate Change and Ozone Loss

2. Key Concepts Changes in Earth’s climate over time Factors affecting climate Possible effects of global warming Adapting to climate change Human impacts on the ozone layer Protecting and restoring the ozone layer

3. Past Climate Changes Past global temperatures Recent trends in global temperatures

5. The Greenhouse Effect Fig: 6-14

7. Table 21-1 Page 464 Table 21-1 Major Greenhouse Gases from Human Activities Greenhouse Gas Carbon dioxide (CO2) Methane (CH4) Nitrous oxide (N2O) Chlorofluorocarbons (CFCs)* Hydrochloro- fluorocarbons (HCFCs) Hydrofluorocarbons (HFCs) Halons Carbon tetrachloride Average Time in the Troposphere 100–120 years 12–18 years 114–120 years 11–20 years (65–110 years in stratosphere) 9–390 15–390 65 42 Human Sources Fossil fuel burning, especially coal (70–75%), deforestation, and plant burning Rice paddies, guts of cattle and termites, landfills, coal production, coal seams, and natural gas leaks from oil and gas production and pipelines Fossil fuel burning, fertilizers, livestock wastes, and nylon production Air conditioners, refrigerators, plastic foams Air conditioners, refrigerators, plastic foams Air conditioners, refrigerators, plastic foams Fire extinguishers Cleaning solvent Relative Warming Potential (compared to CO 2 ) 1 23 296 900–8,300 470–2,000 130–12,700 5,500 1,400

8. Climate Change and Human Activities Increased use of fossil fuels Deforestation Global warming Melting icecaps and glaciers Rising sea level

13. Oceans 5% Bare sand 30–60% Grass 15–25% Figure: The Albedo or reflectivity of the incoming solar energy. Clouds 50–55% Snow 80–90% City 10–15% Forest 5%

14. Factors Affecting the Earth’s Temperature Changes in solar output Changes in Earth’s albedo Moderating effect of oceans Clouds and water vapor Air pollution

15. Today’s sea level Years before present Present 250,000 200,000 150,000 100,000 50,000 0 – 130 0 – 426 0 Height above or below present sea level (meters) Height above or below present sea level (feet)

16. Troposphere Aerosols Greenhouse gases Warming from decrease Cooling from increase CO 2 removal by plants and soil organisms CO 2 emissions from land cleaning, fires, and decay Heat and CO 2 removal Heat and CO 2 emissions Ice and snow cover Natural and human emissions Land and soil Shallow ocean Long-term storage Deep ocean

17. Antarctica Greenland Greenland

18. Some Possible Effects of a Warmer World

21. Solutions: Dealing with the Threat Options Do nothing Do more research Act now to reduce risks Precautionary principle

22. Tree plantation Coal power plant Tanker delivers CO 2 from plant to rig Oil rig Crop field Switchgrass Spent oil reservoir is used for CO 2 deposit CO 2 is pumped down to reservoir through abandoned oil field Abandoned oil field CO 2 is pumped down from rig for deep ocean disposal = CO 2 deposit = CO 2 pumping Removing CO 2 from the Atmosphere

24. Figure 21-20 Page 483

27. Loss of the Ozone Layer: Reasons for Concern Increased incidence and severity of sunburn Increase in eye cataracts Increased incidence of skin cancer Immune system suppression Increase in acid deposition Lower crop yields and decline in productivity

29. Ozone Depleting Chemicals Chlorofluorocarbons (CFCs) Halons Methyl bromide Carbon tetrachloride Methyl chloroform Hydrogen chloride

31. Ozone Depletion in the Stratosphere

32. Seasonal Ozone Layer Thinning at the Poles During four months of each year, up to half of the ozone in the stratosphere over Antarctica is depleted. Ozone loss is often called the ozone hole, but it is actually ozone thinning. The total area of stratosphere that suffers from ozone thinning varies from year to year. In 2003, the area was the second largest ever. The primary culprits are CFCs and other ODCs.

35. Basal Cell Carcinoma Melanoma Squamous Cell Carcinoma

37. Solutions: Protecting the Ozone Layer CFC substitutes Montreal Protocol Copenhagen Protocol