Climate Change and Ozone Loss Chapter 18

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Climate Change and Ozone LossChapter 18
We are embarked on the most colossal ecological
experiment of all time doubling the
concentration in the atmosphere of an entire
planet of one of its most important gases and
we really have little idea of what might
happen. Paul A. Colinvaux
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Key Concepts

• How does the Earths climate fluctuate
• What factors affect climate
• What are the possible effects of global warming
• What can humans do about potential climate change
• How are human activities affecting the ozone
  layer
• What can humans do about changes in the ozone
  layer

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Past Climate Change

• Past global temperatures
• Recent trends in global temperatures

Fig. 18-2 pg 447
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The Natural Greenhouse Effect

• Greenhouse effect
• Greenhouse Gases

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Climate Change and Human Activities

• Increased use of fossil fuels
• Deforestation
• Global warming
• Melting icecaps and glaciers
• Coral reef bleaching

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Projecting Future Changes in Earths Climate

• Climate models (see Spotlight p 457)
• Apparent influence of human activities
• Could be natural changes

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Factors Affecting Changes in Earths Average
Temperature

• Changes in solar output
• Changes in Earths albedo
• Moderating effect of oceans
• Clouds and water vapor
• Air pollution

Fig. 18-13 p 458
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Some Possible Effects of a Warmer World
Fig. 18-16 p 461
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Solutions Dealing with the Threat of Climate
Change
Options

• Do nothing
• Do more research
• Act now to reduce risks
• No-regrets strategy

Fig. 18-20 p 466
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Removing CO2 From The Atmosphere
Tree plantation
Coal power plant
Tanker delivers CO2 from plant to rig
Oil rig
CO2 is pumped down from rig for Deep ocean
disposal
Abandoned oil field
CO2 is pumped down to reservoir through
abandoned oil field
Crop field
Switchgrass field
Spent oil reservoir is used for CO2 deposit
Fig. 18-21 p 467
CO2 deposit CO2 pumping
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Reducing Greenhouse Gas Emissions

• Rio Earth Summit (1992)
• Kyoto Treaty (1997)
• Some US CO2 Reductions

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Ozone Depletion in the Stratosphere
Importance of Ozone

• Terrestrial life
• Reduce sunburn
• Prevents tropospheric ozone

Fig. 18-26, p 473
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Ozone Depleting Chemicals

• Chlorofluorocarbons (CFCs)
• Halons
• Methyl bromide
• Carbon tetrachloride
• Methyl chloroform
• Hydrogen chloride

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Seasonal Thinning at the Poles

• Ozone thinning (hole)

• Polar vortex

Fig. 18-30 pg. 475
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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 yield and decline in productivity

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SolutionsProtecting the Ozone Layer

• CFC substitutes
• Technofixes
• Montreal Protocol

Fig. 18-33 pg. 479