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

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

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

The Greenhouse Effect Greenhouse effect Greenhouse gases (Refer to Table 21-1 p. 464)

Projecting Future Changes in Earth’s Climate Climate models Modeling from the 1990 Apparent influence of human activities Could be natural changes

Climate Change and Human Activities Increased use of fossil fuels Global warming Melting icecaps and glaciers Planet in Peril – Sea Level Rise Rising sea level Deforestation

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

Some Possible Effects of a Warmer World

Possible Benefits from a Warmer Atmosphere Solutions: Dealing with the Threat of Climate Change Less severe winters More precipitation in some dry areas Less precipitation in some wet areas Increased food production in some areas Expanded population and ranges of some species Options Do nothing Do more research Act now to reduce risks Precautionary principle

Removing CO2 from the Atmosphere Capture and sequester Reducing Greenhouse Gas Emissions Kyoto Treaty (1997) U.S. withdraws from Kyoto Treaty (2001) Other reductions in CO2

Loss of the Ozone Layer: Reasons for Concern Increased incidence and severity of sunburn Increase in eye cataracts Increased incidence of skin cancer Skin Cancer Immune system suppression Increase in acid deposition Lower crop yields and decline in productivity Seasonal Ozone Layer Thinning at the Poles Ozone thinning (hole) Polar vortex

Ozone Depleting Chemicals Chlorofluorocarbons (CFCs) Halons Methyl bromide Carbon tetrachloride Methyl chloroform Hydrogen chloride Ozone Depletion in the Stratosphere

Former Uses of CFCs Solutions: Protecting the Ozone Layer Air Conditioners Refrigerators Spray cans Cleaners for electronic parts Sterilizing medical instruments Fumigants for granaries and cargo ships Solutions: Protecting the Ozone Layer CFC substitutes Montreal Protocol Copenhagen Protocol