Transcript ch18_lecture - La Habra High School

Climate Change and Ozone Loss
G. Tyler Miller’s
Living in the Environment
13th Edition
Chapter 18
Modified by Charlotte Kirkpatrick
Dr. Richard Clements
Chattanooga State Technical Community College
Key Concepts
 How does the Earth’s 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
Past Climate Change
 Past global
temperatures
 Recent trends in
global temperatures
Fig. 18-2 p. 447
The Natural Greenhouse Effect
Greenhouse effect Greenhouse gases
(Refer to Table 18-1 p. 448)
Fig. 6-13 p. 128
Climate Change and Human Activities
Increased use of fossil fuels
Deforestation
Refer to Table 18-2 p. 451
Global warming
Melting icecaps and glaciers
Coral reef bleaching
Projecting Future Changes in Earth’s
Climate
 Climate models
(see Spotlight p. 457)
 Apparent influence
of human activities
 Could be natural
changes
Fig. 18-11 p. 455
Factors Affecting Changes in Earth’s
Average Temperature
 Changes in solar output
 Changes in Earth’s albedo
 Moderating effect of
oceans
 Clouds and water vapor
 Air pollution
Fig. 18-13 p. 457
Some Possible Effects of a
Warmer World
Fig. 18-16
p. 461
Solutions: Dealing with the Threat
of Climate Change
Fig. 18-20 p. 466
Options
 Do nothing
 Do more research
 Act now to reduce
risks
 No-regrets strategy
Removing CO2 From the Atmosphere
Tree
plantation
Coal
power plant
Tanker delivers
CO2 from plant
to rig
Abandoned
oil field
CO2 is pumped
down to reservoir
through abandoned oil field
Oil rig
CO2 is
pumped down
from rig for
Deep ocean
disposal
Crop field Switchgrass
field
Spent oil reservoir is
used for CO2 deposit
= CO2 deposit
= CO2 pumping
Fig. 18-21
p. 467
Reducing Greenhouse Gas Emissions
Rio Earth Summit (1992)
Kyoto Treaty (1997)
Some US CO2 Reductions
Refer to Fig. 18-25 p. 472
Ozone Depletion in the Stratosphere
Importance of
Ozone
 Terrestrial
life
 Reduce
sunburn
 Prevents
tropospheric
ozone
Fig. 18-26 p. 473
Ozone Depleting Chemicals
Chlorofluorocarbons (CFCs)
Halons
Methyl bromide
Carbon tetrachloride
Methyl chloroform
Hydrogen chloride
Sources of CFCs
Seasonal Thinning at the Poles
Ozone thinning (hole) Polar vortex
Fig. 18-30 p. 475
Reasons for Concern
 Increased incidence and severity of sunburn
 Increase in eye cataracts
 Increased incidence of skin cancer
 Immune system suppression
Refer to
Fig. 18-32 p. 476
 Increase in acid deposition
 Lower crop yields and decline in productivity
Solutions: Protecting the Ozone Layer
CFC substitutes (see Table 18-3 p. 477)
Technofixes
Montreal Protocol
Fig. 18-33 p. 479