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Climate Change and Ozone Loss. G. Tyler Miller’s Living in the Environment 13 th Edition Chapter 18. Key Concepts. How does the Earth’s climate fluctuate? What factors affect climate? What are the possible affects of global warming? How are human activities affecting the ozone layer?.

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climate change and ozone loss
Climate Change and Ozone Loss

G. Tyler Miller’s

Living in the Environment

13th Edition

Chapter 18

key concepts
Key Concepts

How does the Earth’s climate fluctuate?

What factors affect climate?

What are the possible affects of global warming?

How are human activities affecting the ozone layer?

past global temperatures
Past Global Temperatures

Average temperature over past 900,000 years

17

16

15

14

13

Average surface temperature (°C)

12

11

10

9

900

800

700

600

500

400

300

200

100

Present

Thousands of years ago

past global temperatures1
Past Global Temperatures

Temperature change over past 22,000 years

2

Agriculture established

1

0

-1

End of

last ice

age

Temperature change (°C)

-2

-3

Average temperature over past

10,000 years = 15°C (59°F)

-4

-5

20,000

10,000

2,000

1,000

200

100

Now

Years ago

recent trends in global temperature
Recent Trends in Global Temperature

Temperature change over past 1,000 years

1.0

0.5

0.0

Temperature change (°C)

-0.5

-1.0

1000

1100

1200

1300

1400

1500

1600

1700

1800

1900

2000

2101

Year

recent trends in global temperature1
Recent Trends in Global Temperature

Average temperature over past 130 years

15.0

14.8

14.6

14.4

Average surface temperature (°C)

14.2

14.0

13.8

13.6

1860

1880

1900

1920

1940

1960

1980

2000

2020

Year

climate change
Climate Change
  • Past globaltemperatures
  • Recent trends in global temperatures
how do we know what past temperature changes were
Radioisotopes in rocks and fossils

Plankton and radioisotopes in ocean sediments

Pollen from lake bottoms

Ice cores from ancient glaciers

Tree rings

Radioisotopes in corals

Historical records

Temperature measurements

How do we know what past temperature changes were?
slide10

LOW

PRESSURE

HIGH

PRESSURE

Heat released

radiates to space

Condensation

and

precipitation

Cool, dry

air

Rises, expands, cools

Falls, is compressed, warms

Warm,

dry air

Hot, wet

air

Flows toward low pressure,

picks up moisture and heat

HIGH

PRESSURE

Moist surface warmed by sun

LOW

PRESSURE

HIGH

PRESSURE

LOW

PRESSURE

Natural Cooling Process

climate change and human activities
Climate Change and Human Activities

Increased use of fossil fuels (CO2 ,CH4)

Deforestation (CO2 ,N2O)

Cultivation of Rice Patties (N2O)

Global warming = Enhanced greenhouse effect

Melting icecaps and glaciers

Coral reef bleaching

Other

connections
Connections

14.7

8.4

380

8.0

14.6

375

7.6

14.5

7.2

14.4

365

6.8

14.3

Fossil fuels burn

(billions of metric tons of oil equivalent)

CO2 concentration (ppm)

Temperature (Cº)

355

6.4

14.2

6.0

345

14.1

5.6

14.0

335

5.2

13.9

13.8

4.8

325

1970

1980

1990

2000

2005

Year

Fossil fuels

Temperature

CO2

projecting future changes in earth s climate
Projecting Future Changes in Earth’s Climate

Fig. 18-11 p. 455

  • Climate models(see Spotlight p. 457)
  • Apparent influence of human activities
  • Could be natural changes
factors affecting changes in earth s average temperature
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
slide20

Six Degrees Could

Change the World

some possible effects of a warmer world
Some Possible Effects of a Warmer World

Water Distribution

Plant and Animal Biodiversity Loss

Ocean Currents and Sea Levels

Extreme Weather

Human Population and Health

Agriculture and Forests

solutions dealing with the threat of climate change
Solutions: Dealing with the Threat of Climate Change

Fig. 18-20 p. 466

Options

  • Do nothing
  • Do more research
  • Act now to reduce risks
  • Act now no-regrets strategy
removing co 2 from the atmosphere
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

reducing greenhouse gas emissions
Reducing Greenhouse Gas Emissions

Rio Earth Summit (1992)

106 nations

Scientific uncertainty must not be used as justification to do nothing.

Industrialized nations must take lead in slowing down rate and degree of global warming.

Developed countries voluntarily committed to reducing CO2 to 1990 levels by the year 2000

reducing greenhouse gas emissions1
Reducing Greenhouse Gas Emissions

Kyoto Treaty (1997)

161 nations

Required 38 developed countries to cut greenhouse emissions 5.2% below 1990 levels by 2012..

Did not require developing countries to make cuts.

Allowed emission trading among participating countries.

Was not ratified until 2005

Approximately 180 participating countries.

united states did not ratify kyoto treaty
United States did not ratify Kyoto Treaty -

Treaty fails to require emission reductions from developing countries (81% of world’s population)

Economists predicted it would have devastating impact on U.S. economy and workers

some u s co 2 reductions
Some U.S. CO2 Reductions

Concern among leaders of some U.S. companies.

Several major companies have established targets to reduce greenhouse gas emissions by 10-65% from 1990 levels by 2010.

Automobile companies investing in hybrid gas-electric and fuel cell engines.

Local governments established programs to reduce greenhouse gas emissions.

California first state to require a reduction in CO2 emissions from motor vehicles beginning in 2009.

slide29

A growing number of analysts suggest we should begin to prepare for the possible effects of long-term atmospheric warming and climate change!

slide31

Photochemical ozone

40

25

35

20

Stratosphere

30

Benefical Ozone

25

Stratospheric ozone

15

Altitude (kilometers)

Altitude (miles)

20

10

15

10

5

Troposphere

Harmful Ozone

5

0

0

0

5

10

15

20

Ozone concentration (ppm)

ozone depletion in the stratosphere
Ozone Depletion in the Stratosphere

Importance of Ozone

Essential for terrestrial life

Reduces sunburn

Prevents tropospheric ozone

slide34

Sun

Cl

Cl

C

Cl

F

UV radiation

O

O

O

O

O

Cl

Cl

Cl

Cl

Cl

O

O

O

O

O

Ultraviolet light hits a chlorofluorocarbon (CFC) molecule, such as CFCl3, breaking off a chlorine atom and leaving CFCl2.

Once free, the chlorine atom is off to attack another ozone molecule

and begin the cycle again.

A free oxygen atom pulls

the oxygen atom off

the chlorine monoxide

molecule to form O2.

The chlorine atom attacks an ozone (O3) molecule, pulling an oxygen atom off it and leaving an oxygen

molecule (O2).

The chlorine atom and

the oxygen atom join to

form a chlorine monoxide

molecule (ClO).

Stepped Art

Fig. 20-18, p. 486

ozone depleting chemicals
Ozone Depleting Chemicals
  • Chlorofluorocarbons (CFCs)
  • Methyl bromide (fumigant)
  • Halons (fire extinguishers)
  • Carbon tetrachloride (solvent)
  • Methyl chloroform (cleaning solvent and propellant)
  • N-propyl bromide (solvent)
ozone depletion in the stratosphere2
OZONE DEPLETION IN THE STRATOSPHERE

During four months of each year up to half of the ozone in the stratosphere over Antarctica and a smaller amount over the Artic is depleted.

seasonal thinning at the poles
Seasonal Thinning at the Poles
  • Ozone thinning (hole)
  • Polar vortex

Fig. 18-30 p. 475

reasons for concern
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
slide39

This long-wavelength

(low-energy) form of UV radiation causes aging of the skin, tanning, and sometimes sunburn. It penetrates deeply and may contribute to skin cancer.

This shorter-wavelength (high-energy) form

of UV radiation causes sunburn, premature

aging, and wrinkling. It is largely responsible

for basal and squamous cell carcinomas

and plays a role in malignant melanoma.

Ultraviolet

A

Ultraviolet

B

Thin layer of

dead cells

Hair

Squamous cells

Epidermis

Basal layer

Sweat

gland

Melanocyte cells

Dermis

Basalcell

Blood

vessels

Squamous Cell Carcinoma

Melanoma

Basal Cell Carcinoma

Fig. 20-22, p. 489

solutions protecting the ozone layer
Solutions: Protecting the Ozone Layer
  • Use CFC substitutes
  • Montreal Protocol (1987)
    • only CFCs
  • Copenhagen Protocol (1992)
    • all ODCs
characteristics of global warming and ozone depletion
Characteristics of Global Warming and Ozone Depletion

Global Warming

CO2, CH4, NOx (greenhouse gases)

Absorbs infrared (IR) radiation

Raising the earth’s surface temperature

Decrease burning of fossil fuels

Ozone Depletion

O3, O2, and CFCs

Absorbs ultraviolet (UV) radiation

Decreasing O3 concentration in the stratosphere

Eliminate CFCs