Ecological Issues

Air Pollution,

Climate Change,

and Ozone Depletion

Fig. 15-1, p. 368

Asian Brown Cloud

• http://www.youtube.com/watch?v=qY

YK-2sDN4U

• http://www.youtube.com/watch?v=v-

SEJfpQLSI&NR=1&feature=fvwp

Core Case Study: South Asia’s

Massive Brown Cloud (1)

• Asian Brown Cloud

• India to Bangladesh to China’s Pacific

coast

• Pollutants from fires, cars, industry

• Skies permanently gray or brown

Core Case Study: South Asia’s

Massive Brown Cloud (2)

• Changing weather patterns

• 700,000 premature deaths per year

• Has traveled to the west coast of the

U.S.

• Made worse by global warming

1: What is the Nature of the

Atmosphere?

• Concept 1 The two innermost layers

of the atmosphere are the

troposphere, which supports life, and

the stratosphere, which contains the

protective ozone layer.

Earth’s Atmosphere

• Troposphere

– Extends upward 5-11 miles above

earth’s surface

– Makes up 75–80% earth’s air mass

– 78% N2, 21% O2

– Weather and climate

• Stratosphere

• Ozone layer

Stratosphere

• Stratosphere – Extends from 11-30 miles above Earth’s

surface

– Volume of water vapor less than Troposphere

– Concentration of ozone much higher

• Ozone Layer – Global sunscreen, keeps 95% of harmful UV

radiation from reaching Earth’s surface

Troposphere

Ozone layer

Stratosphere

Tropopause

Stratopause

Mesosphere

Mesopause

Thermosphere

Pressure

Temperature

Fig. 15-2, p. 370

Atmospheric pressure (millibars)

0 200 400 600 800 1,000

(Sea

Level) Pressure = 1,000 Millibars at ground level

Alt

itu

de

(k

ilo

me

ters

)

Alt

itu

de

(m

ile

s)

75

65

55

45

35

25

15

5

–80 –40 0 40 80 120

Temperature (°C)

120

110

100

90

80

70

60

50

40

30

20

10

0

2 What Are the Major Air

Pollution Problems? (1)

• Concept 2A Three major outdoor air

pollution problems are industrial smog

from burning coal, photochemical

smog from motor vehicle and

industrial emissions, and acid

deposition from coal burning and

motor vehicle exhaust.

2 What Are the Major Air

Pollution Problems? (2)

• Concept 2 The most threatening indoor air pollutants are smoke

and soot from wood and coal fires

(mostly in developing countries) and

chemicals used in building materials

and products.

Air pollution

• http://www.youtube.com/watch?v=Hx

_yWFQvJT4&feature=related

Outdoor Air Pollution

• What is air pollution? – Presence of chemicals in atmosphere in concentrations

that are high enough to be harmful

– Stationary and mobile sources

• Primary pollutants-harmful chemicals

emitted directly into the air

• Secondary pollutants- formed when

primary pollutants react with one another and with

other components of air to form new harmful

chemicals

Types of Major Air Pollutants

• Carbon oxides (CO, CO2)

• Nitrogen oxides and nitric acid

(NO, NO2, HNO3)

• Sulfur dioxide and sulfuric acid

(SO2, H2SO4)

• Particulates (SPM)

• Ozone (O3)

• Volatile organic compounds (VOCs)

Carbon Oxides

Carbon monoxide (CO) colorless, odorless

and highly toxic gas that forms during

incomplete combustion of carbon-containing

materials

– Major sources: motor vehicle exhaust,

burning of forests and grasslands, tobacco

smoke, open fires/inefficient stoves for

cooking

– Reacts with Hb in RBCs to decrease ability

of blood to transport O2 to body cells and

tissues

• Carbon dioxide (CO2)

– Colorless, odorless gas

– 93% of atmospheric CO2 result of

natural carbon cycle

– Rest from burning fossil fuels, clearing

forests and grasslands

– Now classified as air pollutant due to

role in climate change

Nitrogen oxides and nitric acid

– Nitric oxide (NO) colorless gas forms

when N and O react at high combustion temps in auto engines and coal-burning power/industrial plants

– In air NO reacts with O to form Nitrogen

dioxide (NO2), reddish brown gas – Collectively NO and NO2 called Nitrogen oxides (NOx)

• Some NO2 reacts with water vapor to

form nitric acid (HNO3) and nitrate

salts (NO3-), components of acid

deposition

• Both NO and NO2 play role in formation of photochemical smog: a mixture of chemicals

formed under influence of sunlight in cities

with heavy traffic

• Nitrous oxide (N2O) greenhouse gas,

emitted from fertilizers and animal

wastes and produced by burning

fossil fuels • Nitrogen oxides can irritate eyes, nose, throat; aggravate

lung ailments, suppress plant growth, and reduce visibility

Sulfur dioxide and sulfuric acid

• Sulfur dioxide (SO2) colorless gas with irritating odor

• 1/3 from natural sources, 2/3 from human sources such

as combustion of sulfur containing coal and oil refining

and smelting

• Can be converted to aerosols, microscopic suspended

droplets of sulfuric acid (H2SO4) and suspended

particles of sulfate (SO4) salts that return to Earth as

component of acid deposition

• SO2, H2SO4 droplets, and suspended particles of sulfate

reduce visibility; aggravate breathing problems; also damage

crops, trees, soils and aquatic life, corrode metals, damage

stone on buildings and statues

• Major component of Asian Brown Cloud

Particulates

• Suspended particulate matter (SPM)

• Variety of solid particles and liquid droplets small and

light enough to remain suspended in air for long periods

• 38% from human sources such as coal burning plants,

motor vehicles, road construction, and tobacco smoke

• Major component of Asian Brown Cloud • These particles can irritate nose, throat; damage lungs;

aggravate asthma and bronchitis, and shorten life

• Also contains toxic particulates; can lead to mutations,

reproductive problems, cancer

• Reduce visibility, corrode metals, discolor clothes and

paints

Ozone

• Ozone (O3), colorless, highly reactive gas,

major ingredient of photochemical smog

• Can cause coughing, breathing problems,

aggravate lung and heart disease, reduce

resistance to colds/ pnuemonia, irritate

eyes, nose, throat

• damages plants, rubber in tires, fabrics,

paints

• Ozone in troposphere near ground

level “bad ozone”

• Ozone in stratosphere “good ozone”

b/c protects us from the sun’s harmful

UV radiation

• Same chemical

• Human activities decreasing “good

ozone” increasing “bad ozone”

Volatile organic compounds

(VOCs) • VOC’s are organic compounds that exist as gases in the

atmosphere or that evaporate into the atmosphere

• Ex. hydrocarbons emitted by leaves of many plants and

methane (CH4) a greenhouse gas 20 times more

effective per molecule than CO2 is at warming

atmosphere

• 1/3 from natural sources, 2/3 human sources; rice

paddies, landfills, oil and natural gas wells, cows

• Other VOCs are liquids that evaporate into atmosphere

ex. Benzene and other industrial solvents, dry cleaning

fluids, components of gasoline, plastics, and other

products

Most NO3– and SO4

2– salts

Mobile

Sources Natural Stationary

Secondary Pollutants

Primary Pollutants

Most hydrocarbons

Most suspended particles

CO2 CO

SO2

PANs

SO3 NO2 NO

H2SO4 HNO3

O3 H2O2

Fig. 15-3, p. 371

Sources and types of air pollutants

In Class

• List the major outdoor air pollutants,

describe, and give their harmful effects.

Describe the relationship in the graph below.

Industrial Smog

• Burning coal – Sulfur dioxide, sulfuric acid, suspended particles (gray

air smog)

– Coal-burning a major contributor to Asian Brown

Cloud

• Developed versus developing

countries – Air pollution control in the U.S. and Europe

– China, India, Ukraine

Photochemical Smog

• Photochemical reactions: chemical

rxn activated by sunlight

• Photochemical smog: mixture of primary

and secondary pollutants formed under the influence

of UV radiation from the sun

– Brown-air smog (contains NO2)

• Sources

• Health effects

• Urban areas

Fig. 15-4, p. 373

Photochemcial smog in Santiago, Chile

Natural Factors That Reduce Air

Pollution

• Particles heavier than air

• Rain and snow

• Salty sea spray from oceans

• Winds

• Chemical reactions

Natural Factors That Increase

Air Pollution

• Urban buildings

• Hills and mountains

• High temperatures

• VOC emissions from certain trees

and plants

• Grasshopper effect

• Temperature inversions

http://www.lchs.wolfcreek.ab.ca/lcsweb/Staff/sschultz/Sci30/007DA42D

-000F810F.5/Grasshopper%20effect.jpg

http://www.airquality.utah.gov/Public-Interest/Current-Issues/cache-

valley-PM/Images/Inversion.jpg

Acid Deposition

• Sulfur dioxides and nitrogen oxides

• Wet and dry deposition

• Acid rain

• Regional air pollution

– Midwest coal-burning power plants

– Prevailing winds

Lakes in deep soil high in limestone are buffered

Lakes in shallow soil low in limestone become acidic

Wet acid deposition (droplets of H2SO4 and HNO3 dissolved in rain and snow)

Dry acid deposition (sulfur dioxide gas and particles of sulfate and nitrate salts)

Windborne ammonia gas and some soil particles partially neutralize acids and form dry sulfate and nitrate salts

Sulfur dioxide

(SO2) and NO

Nitric oxide (NO)

Acid fog

Transformation

to sulfuric acid

(H2SO4) and nitric

acid (HNO3)

Wind

Fig. 15-5, p. 374

Acid deposition: consists of rain, snow, dust, or gas with pH less than 5.6

Fig. 15-6, p. 375

Potential problem areas because of sensitive soils

Potential problem areas because of air pollution: emissions leading to acid deposition

Current problem areas (including lakes and rivers)

Regions where acid deposition is now a problem and regions with the potential to

develop this problem

Harmful Effects of Acid

Deposition

• Structural damage

• Respiratory diseases in humans

• Toxic metal leaching

• Kills fish and other aquatic organisms

• Leaches plant nutrients from soil

• Acid clouds and fog at mountaintops

Fig. 15-7, p. 376

Reduce air pollution by

improving energy efficiency

Tax emissions of SO2

Remove NOx from motor

vehicular exhaust

Remove SO2 particulates and NOx from smokestack gases

Increase use of renewable

energy resources

Increase natural gas use

Burn low-sulfur coal

Prevention

Reduce coal use

Add phosphate fertilizer to neutralize acidified lakes

Cleanup

Add lime to neutralize acidified lakes

Acid Deposition

Solutions

Indoor Air Pollution

• According to WHO indoor air pollution is

world’s most serious air pollution

problem especially for poor people

• Developing countries

– Indoor cooking and heating

• Often higher concentration in buildings and cars

• Most time is spent indoors or in cars

• EPA – top cancer risk

Major Indoor Air Pollutants

• Tobacco smoke

• Formaldehyde

• Radioactive radon-222 gas

• Very small particles

Fig. 15-8, p. 377

Asbestos Source: Pipe insulation, vinyl ceiling and floor tiles Threat: Lung disease, lung cancer

Carbon monoxide Source: Faulty furnaces, unvented gas stoves and kerosene heaters, woodstoves Threat: Headaches, drowsiness, irregular heartbeat, death

Methylene chloride Source: Paint strippers and thinners Threat: Nerve disorders, diabetes

Tobacco smoke Source: Cigarettes Threat: Lung cancer, respiratory ailments, heart disease

Radon-222 Source: Radioactive soil and rock surrounding foundation, water supply Threat: Lung cancer

Benzo-α-pyrene Source: Tobacco smoke, woodstoves Threat: Lung cancer

Styrene Source: Carpets, plastic products Threat: Kidney and liver damage

Formaldehyde Source: Furniture stuffing, paneling, particleboard, foam insulation Threat: Irritation of eyes, throat, skin, and lungs; nausea; dizziness

Tetrachloroethylene Source: Dry-cleaning fluid fumes on clothes Threat: Nerve disorders, damage to liver and kidneys, possible cancer

Para-dichlorobenzene Source: Air fresheners, mothball crystals Threat: Cancer

Chloroform Source: Chlorine-treated water in hot showers Possible threat: Cancer

1,1,1-Trichloroethane Source: Aerosol sprays Threat: Dizziness, irregular breathing

Nitrogen oxides Source: Unvented gas stoves and kerosene heaters, woodstoves Threat: Irritated lungs, children's colds, headaches

Particulates Source: Pollen, pet dander, dust mites, cooking smoke particles Threat: Irritated lungs, asthma attacks, itchy eyes, runny nose, lung disease

Air Pollution and the Human

Respiratory System • Natural protective system; hairs in nose

filter out large particles, mucus captures

particles, cilia (tiny mucus coated, hair-like

structures) transport pollutants they trap

• Lung cancer, chronic bronchitis,

emphysema, asthma

• Premature deaths

• Air pollution kills 2.4 million people

prematurely every year worldwide

Bronchioles

Right lung

Bronchus

Trachea (windpipe)

Pharynx (throat)

Oral cavity

Nasal cavity

Alveolar sac

(sectioned)

Alveoli

Bronchioles

Alveolar duct

Goblet cell

(secreting

mucus)

Mucus

Epithelial cell

Cilia

Fig. 15-9, p. 378

Major components of respiratory system

Fig. 15-10, p. 378

Deaths per 100,000 adults per year

<1 1–5 5–10 10–20 20–30 30+

Premature deaths from

air pollution in US

15-3 How Should We Deal with

Air Pollution?

• Concept 15-3 Legal, economic, and

technological tools can help clean up

air pollution, but the best solution is to

prevent it.

U.S. Outdoor Air Pollution

Control Laws

• Clean Air Acts 1970, 1977, 1990

• Air-quality standards for 6 major

outdoor pollutants – Carbon monoxide (CO), nitrogen dioxide

(NO2), sulfur dioxide (SO2), SPM, ozone

(O3), and lead

• Levels of these 6 pollutants have fallen

dramatically between 1980 and 2008

*Improving Air Pollution Laws (1)

• Emphasize pollution prevention

• Increase fuel economy standards

• Regulate emissions from two-cycle

engines

• Regulate ultra-fine particles

*Improving Air Pollution Laws (2)

• Increase regulations at airports

• Decrease urban ozone

• Increase regulations for indoor air

pollution

• Better enforcement of Clean Air Act

*Using the Marketplace to

Reduce Air Pollution

• Clean Air Act of 1990 authorized

emissions trading (cap and trade) program

– Enables 110 most polluting coal burning

power plants in 21 states to buy and sell SO2

pollution rights

• Proponents – cheaper and more efficient

• Critics – companies buy their way out

• Success depends on cap being gradually

lowered

Fig. 15-11, p. 380

Shift to less polluting

energy sources

Remove pollutants after

combustion

Dispersion or Cleanup

Prevention

Stationary Source Air Pollution

Solutions

Burn low-sulfur coal

Remove sulfur from coal

Convert coal to a liquid

or gaseous fuel

Disperse emissions above

thermal inversion layer with

tall smokestacks

Tax each unit of pollution

produced

Fig. 15-12, p. 381

Give large tax write-offs or rebates for buying low- polluting, energy efficient vehicles

Set strict

emission

standards

Cleanup Prevention

Motor Vehicle Air Pollution

Solutions

Use mass transit

Walk or bike

Use less polluting fuels

Improve fuel efficiency

Get older, polluting

cars off the road

Inspect car

exhaust

systems

twice a year

Require

emission

control devices

Fig. 15-13, p. 381

Solutions

Indoor Air Pollution

Clean ceiling tiles and line AC ducts to prevent release of mineral fibers

Use adjustable fresh air vents for work spaces

Cleanup or Dilution

Prevention

Use exhaust hoods for stoves and appliances burning natural gas

Use efficient venting systems for wood- burning stoves

Circulate a building’s air through rooftop greenhouses

Change air more frequently

Increase intake of outside air

Use less polluting substitutes for harmful cleaning agents, paints, and other products

Use office machines in well- ventilated areas

Prevent radon infiltration

Set stricter formaldehyde emissions standards for carpet, furniture, and building materials

Ban smoking or limit it to well-ventilated areas

Fig. 15-14, p. 381

Fig. 15-15, p. 382

Solutions

Air Pollution

Indoor Outdoor

Rely more on renewable energy (especially solar cells, wind, geothermal and solar-produced hydrogen)

Improve energy efficiency to reduce fossil fuel use Rely more on lower-polluting natural gas

Transfer energy efficiency, renewable energy, and pollution prevention technologies to developing countries

Distribute cheap and efficient cookstoves or solar cookers to poor families in developing countries

Develop simple and cheap tests for indoor pollutants such as particulates, radon, and formaldehyde

Reduce or ban indoor smoking

Reduce poverty

15-4 How Might the Earth’s

Climate Change in the Future?

• Concept 15-4 Considerable scientific

evidence indicates that emissions of

greenhouse gases into the earth’s

atmosphere from human activities will

lead to significant climate change

during this century.

Climate Change

• http://www.youtube.com/watch?v=oJ

AbATJCugs

Past Climate Changes

• Glacial and interglacial periods over past

900,000 yrs

• Global cooling and global warming

• Measurement of past temperature changes

– Radioisotopes in rocks and fossils

– Tiny bubbles of ancient air found in ice cores

from glaciers

– Tree rings

– Historical measurements since 1861

Stepped Art

AVERAGE TEMPERATURE (over past 900,000 years AVERAGE TEMPERATURE (over past 130 years

TEMPERATURE CHANGE (over past 22,000 years TEMPERATURE CHANGE (over past 1,000 years

Fig. 15-16, p. 383

Fig. 15-17, p. 383

Ice cores are extracted by drilling deep holes into ancient glaciers at various sites like

this one in Antarctica. .

The Greenhouse Effect

• Life on Earth is totally dependent on natural

greenhouse effect

• Without this greenhouse effect, the world would

be too cold to support the forms of life we find

today

• Natural greenhouse gases

– Water vapor (H2O)

– Carbon dioxide (CO2)

– Methane (CH4)

– Nitrous Oxide (N2O)

List the 4 natural greenhouse gasses.

What is the importance of the

greenhouse effect?

• http://earthguide.ucsd.edu/earthguide/

diagrams/greenhouse/

Evidence to Support Global

Warming (1)

• Intergovernmental Panel on Climate

Change

• 2007 IPCC report

• Rise in average global surface

temperature

• 10 warmest years on record since

1970

Evidence to Support Global

Warming (2)

• Annual greenhouse gas emissions up

70% between 1970 and 2008

• Changes in glaciers, rainfall patterns,

hurricanes

• Sea level rise in this century 4–8

inches

Melting of Alaska’s Muir Glacier in Glacier Bay National Park and Preserve between

1948 and 2004. Mountain glaciers are now melting everywhere in the world.

Fig. 15-19, p. 385

Sept. 1979

Russia

Alaska (U.S.)

Canada

Greenland North pole

*

Sept. 2008

Russia

Alaska (U.S.)

Canada

Greenland North pole

*

The big melt. Each summer, some of the floating sea ice in the Arctic Sea melts and

Then refreezes during winter. But in recent years, rising atmospheric and ocean temps

have caused more and more ice to melt. Satellite data show a 39% drop in the average

Cover of summer Arctic ice between 1979 and 2007. Such summer ice may be gone by

2037, and perhaps earlier.

CO2 Emissions Are the Major Culprit

• 1850: 285 ppm (Start of the Industrial Revolution)

• 2009: 388 ppm

• Over 450 ppm is tipping point (could set into

motion large-scale climate changes for hundreds to thousands of

years)

• 350 ppm as intermediate goal

Science Focus: Scientific Consensus about

Future Global Temperature Changes?

• Temperature as a function of

greenhouse gases

• Mathematical models

• Model data and assumptions

• Predictions and model reliability

• Recent warming due to human

activities

Troposphere

CO2 emissions from land clearing,

fires, and decay

CO2 removal by plants and soil organisms

Heat and CO2 removal

Heat and CO2 emissions

Shallow ocean

Long-term storage

Deep ocean

Land and soil biota

Ice and snow cover

Natural and human emissions

Cooling from increase

Warming from decrease

Greenhouse gases

Aerosols

Fig. 15-A, p. 386

Simplified model of some major processes that interact to determine the average

temperature and greenhouse gas content of the lower atmosphere and thus the Earth’s

climate. Red arrows show processes resulting in warming; blue cooling.

Fig. 15-B, p. 387

What Role for Oceans in

Climate Change?

• Oceans help to moderate earth’s avg surface

temp and thus climate by removing about 25-

30% of CO2 pumped into lower atmosphere by

human activities

• Absorb heat from lower atmoshere and slowly

transfer some CO2 to deep ocean

• CO2 solubility decreases with increasing

temperature

• Upper ocean getting warmer

• Acidity of ocean increasing

15-5 What Are Some Possible Effects

of a Projected Climate Change?

• Concept 15-5 The projected change

in the earth’s climate during this

century could have severe and long-

lasting consequences, including

increased drought and flooding, rising

sea levels, and shifts in locations of

agriculture and wildlife habitats.

Potential Severe Consequences

• Rapid projected temperature increase

• 2 Cº inevitable

• 4 Cº possible

• Effects will last for at least 1,000

years

Fig. 15-20, p. 389

Harmful Effects of Global

Warming (1)

• Excessive heat

• Drought

• Ice and snow melt

• Rising sea levels

• Extreme weather

Harmful Effects of Global

Warming (2)

• Threat to biodiversity

• Food production may decline

• Change location of agricultural crops

• Threats to human health

Fig. 15-21, p. 390

Glaciers covering about 80% of Greenland, the world’s largest island, contain about 10%

of the world’s freshwater. This is enough water to raise global sea level by 23 ft if they all

melt. Complete melting unlikely, but partial summer melting of some of its glacial ice

increased dramatically between 1982 and 2007.

Fig. 15-22, p. 391

Areas of Florida that will be flooded (red) if the average sea level rises by 1 meter

(3.3 ft).

S45

15-6 What Can We Do to Slow

Projected Climate Change?

• Concept 15-6 To slow the rate of

projected climate change, we can

increase energy efficiency, sharply

reduce greenhouse gas emissions,

rely more on renewable energy

resources, and slow population

growth.

Options to Deal with Climate

Change

• Two approaches:

1. Drastically reduce greenhouse gas

emissions

2. Develop strategies to reduce its

harmful effects

• Mix both approaches

• Governments beginning to act

Fig. 15-23, p. 393

Solutions

Slowing Climate Change

Cleanup Prevention

Limit urban sprawl

Sequester CO2 deep underground (with no leaks allowed)

Cut fossil fuel use (especially coal)

Shift from coal to natural gas Improve energy efficiency

Shift to renewable energy resources

Transfer energy efficiency and renewable energy technologies to developing countries

Reduce deforestation

Slow population growth

Reduce poverty

Use more sustainable agriculture and forestry

Remove CO2 from smokestack and vehicle emissions

Store (sequester) CO2 by planting trees

Sequester CO2 in soil by using no-till cultivation and taking cropland out of production

Use animal feeds that reduce CH4 emissions from cows (belching)

Repair leaky natural gas pipelines and facilities

Sequester CO2 in the deep ocean (with no leaks allowed)

Reducing the Threat of Climate

Change (1)

• Improve energy efficiency to reduce

fossil fuel use

• Shift from coal to natural gas

• Improve energy efficiency

• Shift to renewable energy sources

Reducing the Threat of Climate

Change (2)

• Transfer appropriate technology to

developing countries

• Reduce deforestation

• Sustainable agriculture and forestry

• Reduce poverty

• Slow population growth

Reducing the Threat of Climate

Change (3) • Decrease CO2 emissions

• Sequester CO2

– Plant trees

– Agriculture

– Underground

– Deep ocean

• Repair leaking natural gas lines

• Reduce methane emissions from animals

Science Focus: Is Capturing and

Storing CO2 the Answer? (1)

• Global tree planting

• Restore wetlands

• Plant fast-growing perennials

Science Focus: Is Capturing and

Storing CO2 the Answer? (2)

• Preserve natural forests

• Seed oceans with iron to promote

growth of phytoplankton

• Sequester carbon dioxide

underground and under the ocean

floor

CO2 is pumped

down from rig for

disposal in deep

ocean or under

seafloor sediments

Deep, saltwater-filled cavern

Spent coal

bed cavern

CO2 is pumped

underground

Spent oil or

natural gas

reservoir

Crop field Switchgrass

Abandoned

oil field

Tree plantation Coal power

plant

Tanker delivers

CO2 from plant

to rig Oil rig

Fig. 15-C, p. 394

= CO2 pumping

= CO2 deposit

• What are the limitations to carbon capture

and storage?

Government Roles in Reducing the

Threat of Climate Change (1)

• Regulate carbon dioxide and

methane as pollutants

• Carbon taxes

• Cap total CO2 emissions

• Subsidize energy-efficient

technologies

• Technology transfers

Government Roles in Reducing the

Threat of Climate Change (2)

• International climate negotiations

• Kyoto Protocol (US withdrew in 2001)

• Act locally – Costa Rica, aims to be first country to be carbon

neutral

– U.S. states; 30 US states had greenhouse gas

reduction programs by 2009

– Large corporations such as Alcoa, DuPont, IBM,

Toyota, General Electric have set goals for reducing

greenhouse gas emissions

– Colleges and universities; such as Oberlin College

Fig. 15-24, p. 396

Expand existing

wildlife reserves

toward poles

Prohibit new construction

on low-lying coastal areas

or build houses on stilts

Stockpile 1- to 5-year

supply of key foods

Move people away

from low-lying

coastal areas

Waste less water

Develop crops that

need less water

Connect wildlife

reserves with corridors

Move hazardous material storage

tanks away from coast

Fig. 15-25, p. 396

Ways to prepare for possible long term harmful effects of climate change.

15-7 How Have We Depleted Ozone in the

Stratosphere and What Can We Do about It?

• Concept 15-7A Widespread use of

certain chemicals has reduced ozone

levels in the stratosphere and allowed

more harmful ultraviolet radiation to reach

the earth’s surface.

• Concept 15-7B To reverse ozone

depletion, we need to stop producing

ozone-depleting chemicals and adhere to

the international treaties that ban such

chemicals.

Human Impact on

the Ozone Layer

• Location and purpose of the ozone

layer

– Blocks UV-A and UV-B radiation

• Seasonal and long-term depletion of

ozone

• Threat to humans, animals, plants

• Causes – chlorofluorocarbons (CFCs)

Individuals Matter: Banning of

Chlorofluorocarbons (CFCs) • Chemists Rowland and Molina –

– Nobel Prize in 1995

• Called for ban

– Remain in atmosphere

– Rise into stratosphere

– Break down into atoms that accelerate ozone depletion

– Stay in stratosphere for long periods

• Defended research against big industry

Former Uses of CFCs

• Coolants in air conditioners and

refrigerators

• Propellants in aerosol cans

• Cleaning solutions for electronic parts

• Fumigants

• Bubbles in plastic packing foam

Fig. 15-26, p. 398

Fig. 15-27, p. 398

Reversing Ozone Depletion

• Stop producing ozone-depleting

chemicals

• Slow recovery

• Montreal Protocol

• Copenhagen Protocol

• International cooperation

Three Big Ideas from This

Chapter - #1

All countries need to step up efforts to

control and prevent outdoor and

indoor air pollution.

Three Big Ideas from This

Chapter - #2

Reducing the possible harmful effects

of projected rapid climate change

during this century requires

emergency action to cut energy

waste, sharply reduce greenhouse

gas emissions, rely more on

renewable energy resources, and

slow population growth.

Three Big Ideas from This

Chapter - #3

We need to continue phasing out the

use of chemicals that have reduced

ozone levels in the stratosphere and

allowed more harmful ultraviolet

radiation to reach the earth’s surface.

Teacher’s Guide to Climate Change

• http://hdgc.epp.cmu.edu/teachersguid

e/teachersguide.htm

• http://education.usgs.gov/secondary.h

tml