Air Pollution, Climate Change, and Ozone Depletion

Chapter 18 and 19

Core Case Study: Volcanoes and Climate Change (1)

Study volcano to understand climate change

Mount Pinatubo – 1991• Second largest volcanic eruption of 20th century• Massive release of air pollution globally

Opportunity to test climate models

Core Case Study: Volcanoes and Climate Change (2)

Predictions matched observations

Global climate change

Mount Pinatubo in the Philippines on June 12, 1991

Fig. 15-1, p. 344

15-1 What Are the Major Air Pollution Problems? (1)

Concept 15-1A 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.

15-1 What Are the Major Air Pollution Problems? (2)

Concept 15-1B The most threatening indoor air pollutants are smoke and soot from wood and coal fires (in developing countries) and chemicals used in building materials and products (in developed countries).

Earth’s Atmosphere

Troposphere• 75–80% earth’s air mass

• 78% N2, 21% O2

Stratosphere

Ozone layer

Layering of the Earth’s Atmosphere

Fig. 15-2, p. 346

Troposphere

Ozone layer

Stratosphere

Tropopause

Stratopause

Mesosphere

Mesopause

Thermosphere

Pressure

Temperature

Outdoor Air Pollution

What is air pollution?

Stationary and mobile sources

Primary pollutants

Secondary pollutants

Types of Major Air Pollutants (1)

Carbon oxides (CO)

Nitrogen oxides and nitric acid (NO, HNO3)

Sulfur dioxide and sulfuric acid (SO2, H2SO4)

Particulates (SPM)

Ozone (O3)

Types of Major Air Pollutants (2)

Volatile organic compounds (VOCs)

Radioactive radon (Rn)

Sources and Types of Air Pollutants

Fig. 15-3, p. 347

Most NO3– and SO4

2– salts

Mobile

Sources Natural Stationary

Secondary Pollutants

Primary Pollutants

Most hydrocarbonsMost suspended particles

CO2CO

SO2

PANs

SO3

NO2NO

H2SO4HNO3

O3H2O2

Science Focus: Using Lichens to Detect Air Pollution

Indicators of air pollution• Mine canaries• Lichens

Isle Royale in Lake Superior

Lichens Growing on Slate Rock

Fig. 15-A, p. 348

Industrial Smog

Burning coal• Sulfur dioxide, sulfuric acid, suspended particles

Developed versus developing countries• Air pollution control in the U.S. and Europe• China, India, Ukraine, Eastern Europe

Photochemical Smog

Photochemical reactions

Photochemical smog• Brown-air smog

Sources

Climate effects

Urban areas

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 (1)

Urban buildings

Hills and mountains

High temperatures

VOC emissions from certain trees and plants

Natural Factors That Increase Air Pollution (2)

Grasshopper effect

Temperature inversions

Acid Deposition

Sulfur dioxides and nitrogen oxides

Wet and dry deposition

Acid rain

Regional air pollution• Midwest coal-burning power plants• Prevailing winds

Acid Deposition

Fig. 15-4, p. 351

Lakes in deepsoil high in limestoneare buffered

Lakes in shallow soillow in limestonebecome acidic

Wet acid deposition(droplets of H2SO4 andHNO3 dissolved in rainand snow)

Dry acid deposition(sulfur dioxide gasand particles ofsulfate and nitrate salts)

Windborne ammonia gasand some soil particles partiallyneutralize acids and form drysulfate and nitrate salts

Sulfur dioxide(SO2) and NO

Nitric oxide (NO)

Acid fog

Transformation to sulfuric acid (H2SO4) and nitric acid (HNO3)

Wind

Current and Potential Problems with Acid Deposition

Fig. 15-5, p. 351

Harmful Effects of Acid Deposition (1)

Respiratory diseases in humans

Toxic metal leaching

Structural damage

Kills fish and other aquatic organisms

Harmful Effects of Acid Deposition (2)

Leaches plant nutrients from soil

Acid clouds and fog at mountaintops

Impacts of Air Pollution on Trees and Water

Fig. 15-6, p. 353

Leachingof soilnutrients

AcidsRelease oftoxicmetal ions

Rootdamage

Reduced nutrientand water uptake

Tree death

Increasedsusceptibility todrought, extremecold, insects,mosses, anddisease organisms

Reducedphotosynthesisand growth

Direct damage toleaves and bark

Soil acidification

Groundwater

Lake

OthersO3

NOx

Emissions

SO2

H2O2

PANs

Aciddeposition

Reducing Acid Deposition

Fig. 15-7, p. 353

Indoor Air Pollution

Often higher concentration in buildings and cars

Most time is spent indoors or in cars

EPA – top cancer risk

Sick-building syndrome (SBS)

Developing countries • Indoor cooking and heating

Major Indoor Air Pollutants

Tobacco smoke

Formaldehyde

Radioactive radon-222 gas

Very small particles

Important Indoor Air Pollutants

Fig. 15-8, p. 354

AsbestosSource: Pipe insulation, vinylceiling and floor tilesThreat: Lung disease, lung cancer

Carbon monoxideSource: Faulty furnaces,unvented gas stoves andkerosene heaters,woodstovesThreat: Headaches,drowsiness, irregularheartbeat, death

Methylene chlorideSource: Paint strippers and thinnersThreat: Nerve disorders, diabetes

Tobacco smokeSource: CigarettesThreat: Lung cancer, respiratoryailments, heart disease

Radon-222Source: Radioactive soiland rock surroundingfoundation, water supplyThreat: Lung cancer

Benzo-α-pyreneSource: Tobacco smoke,woodstovesThreat: Lung cancer

StyreneSource: Carpets,plastic productsThreat: Kidney andliver damage

FormaldehydeSource: Furniture stuffing,paneling, particleboard,foam insulationThreat: Irritation of eyes,throat, skin, and lungs;nausea; dizziness

TetrachloroethyleneSource: Dry-cleaningfluid fumes on clothesThreat: Nerve disorders,damage to liver andkidneys, possible cancer

Para-dichlorobenzeneSource: Air fresheners,mothball crystalsThreat: Cancer

ChloroformSource: Chlorine-treated water inhot showersPossible threat: Cancer

1,1,1-TrichloroethaneSource: Aerosol spraysThreat: Dizziness,irregular breathing

Nitrogen oxidesSource: Unvented gasstoves and keroseneheaters, woodstovesThreat: Irritated lungs,children's colds,headaches

ParticulatesSource: Pollen, petdander, dust mites,cooking smoke particlesThreat: Irritated lungs,asthma attacks, itchyeyes, runny nose,lung disease

Air Pollution and the Human Respiratory System

Natural protective system

Lung cancer, chronic bronchitis, emphysema, asthma

Premature deaths

Fossil fuels• Coal• Diesel engines

Human Respiratory System

Fig. 15-9, p. 355

Bronchioles

Right lung

Bronchus

Trachea (windpipe)

Pharynx (throat)

Oral cavity

Nasal cavity

Alveolar sac(sectioned)

Alveoli

Bronchioles

Alveolar duct

Goblet cell(secretingmucus)

Mucus

Epithelial cell

Cilia

Healthy and Diseased Lungs

Fig. 15-10, p. 356

Premature Deaths from Air Pollutionin the United States

Fig. 15-11, p. 356

15-2 How Should We Deal with Air Pollution?

Concept 15-2 Legal, economic, and technological tools can help clean up air pollution, but scientists call for much greater emphasis on preventing air pollution.

U.S. Outdoor Air Pollution Control Laws

Clean Air Acts

National Ambient Air Quality Standards

Hazardous Air Pollutants

Good news

Bad news

Improving Air Pollution Laws (1)

Emphasize pollution prevention

Increase fuel economy standards

Regulate emissions from two-cycle engines

Regulate ocean-going ships

Increase regulations at airports

Improving Air Pollution Laws (2)

Specifically regulate CO2

Increase regulations for indoor air pollution

Better enforcement of Clean Air Act

Using the Marketplace to Reduce Air Pollution

Emissions trading (cap and trade) program

Proponents – cheaper and more efficient

Critics – companies buy their way out

Success depends on cap

Good news and bad news

Solutions: Stationary Source Air Pollution

Fig. 15-12, p. 358

Solutions: Motor Vehicle Air Pollution

Fig. 15-13, p. 359

Solutions: Indoor Air Pollution

Fig. 15-14, p. 359

What Can You Do?

Fig. 15-15, p. 360

Solutions: Air Pollution

Fig. 15-16, p. 360

15-3 How Might the Earth’s Temperature and Climate Change in the Future?

Concept 15-3 Evidence indicates that the earth’s atmosphere is warming, mostly because of human activities, and that this will lead to significant climate change during this century.

Past Climate Changes

Glacial and interglacial periods

Measurement of past temperature changes• Rocks and fossils• Ocean sediments• Ice cores from glaciers• Boreholes deep in earth’s surface

Estimated Changes in the Average Global Temperature

Fig. 15-17a, p. 361

Fig. 15-17b, p. 361

Fig. 15-17c, p. 361

Fig. 15-17d, p. 361

Fig. 15-17, p. 361

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

Ice Cores: Records of Past Climates

Fig. 15-18, p. 361

The Greenhouse Effect

Earth’s natural greenhouse effect

Natural greenhouse gases• Water vapor (H2O)

• Carbon dioxide (CO2)

• Methane (CH4)

• Nitrous Oxide (N2O)

Enhanced greenhouse effect • Global warming

Evidence to Support Global Warming (1)

2007 IPCC report

Rise in average global surface temperature

13 warmest years on record since 1990

Arctic temperatures have risen twice as fast

Evidence to Support Global Warming (2)

Changes in glaciers, rainfall patterns, hurricanes

Sea level rise in this century 4–8 inches

Melting of Alaska’s Muir Glacier

Fig. 15-19, p. 363

Fig. 15-19, p. 363

Stepped Art

Average Drop in Arctic Sea Ice (1979-2005)

Fig. 15-20, p. 363

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

Simplified Model to Determine Average Temperature and Greenhouse Gas Content

Fig. 15-B, p. 364

Troposphere

CO2 emissions fromland clearing,fires, and decay

CO2 removalby plants andsoil organisms

Heat andCO2 removal

Heat andCO2 emissions

Shallow ocean

Long-termstorage

Deep ocean

Land and soil biota

Ice and snow cover

Natural and human emissions

Coolingfromincrease

Warmingfromdecrease

Greenhousegases

Aerosols

Sun

Measured Average Temperatures and Future Predictions

Fig. 15-C, p. 365

Potential Consequences of Enhanced Global Warming (1)

Rate and extent of temperature changes

Tipping point

Droughts and floods

Extinctions

Intense storms and hurricanes

Potential Consequences of Enhanced Global Warming (2)

Diseases

Economic and social disruption

Factors Affecting the Earth’s Temperature

Ability of oceans to store carbon dioxide

Effects of cloud cover

Aerosol pollutants

Photosynthesis

15-4 What Are Some Possible Effects of a Warmer Earth?

Concept 15-4 Some areas will benefit from a warmer climate and others will suffer from melting ice, rising sea levels, more extreme weather events, increased drought and floods, and shifts in locations of wildlife habitats and agricultural areas.

Beneficial Effects of Global Warming

Less severe winters

More precipitation in dry areas

Less precipitation in wet areas

Increased food production for some areas

Harmful Effects of Global Warming (1)

Excessive heat

Drought

Decreased food production

Arctic ice and snow melt

Harmful Effects of Global Warming (2)

Rising sea levels

Melting permafrost

Changing ocean currents

Extreme weather

Harmful Effects of Global Warming (3)

Threat to biodiversity

Change location of agricultural crops

Threats to human health

Rising Sea Levels Threaten Low-lying Islands

Fig. 15-21, p. 369

15-5 What Can We Do about Global Warming?

Concept 15-5A We can slow the rate of climate change by increasing energy efficiency, relying more on renewable energy resources, and reducing greenhouse gas emissions.

Concept 15-5B Governments can tax greenhouse gas emissions, subsidize energy efficiency and renewable energy use, and cooperate internationally, and individuals and institutions can sharply reduce their greenhouse gas emissions.

Difficulties in Dealing with Climate Change

Problem is global

Long-lasting effects

Long-term political issue

Impacts are not spread evenly

Change can disrupt economies and lifestyles

Options to Deal with Climate Change

Basic approaches:• Drastically reduce greenhouse gas emissions• Develop strategies to reduce its harmful effects

Mix both approaches

Governments beginning to act

Solutions to Global Warming

Fig. 15-22, p. 371

Removing Carbon Dioxide from the Atmosphere

Fig. 15-23, p. 372

CO2 is pumpeddown from rig fordisposal in deepocean or underseafloor sediments

Deep, saltwater-filled cavern

Spent coalbed cavern

CO2 is pumpedunderground

Spent oil ornatural gasreservoir

Crop fieldSwitchgrass

Abandonedoil field

Tree plantationCoal powerplant

Tanker deliversCO2 from plantto rig

Oil rig

Government Roles in Reducing the Threat of Climate Change (1)

Regulate carbon dioxide as a pollutant

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

Act locally

What Can You Do?

Fig. 15-24, p. 375

Preparing for Climate Changes

Fig. 15-25, p. 375

Expand existingwildlife reservestoward poles

Prohibit new constructionon low-lying coastal areasor build houses on stilts

Stockpile 1- to 5-yearsupply of key foods

Move people awayfrom low-lyingcoastal areas

Waste less water

Develop crops thatneed less water

Connect wildlifereserves with corridors

Move hazardous material storagetanks away from coast

15-6 How Have We Depleted Ozone in the Stratosphere and What Can We Do about It?

Concept 15-6A Widespread use of certain chemicals has reduced ozone levels in the stratosphere, which allows more harmful ultraviolet radiation to reach the earth’s surface.

Concept 15-6B To reverse ozone depletion, we must 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

Seasonal and long-term depletion of ozone

Causes – chlorofluorocarbons (CFCs)

Individuals Matter: Banning of Chlorofluorocarbons (CFCs)

Chemists Rowland and Molina

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

Ozone Thinning

Seasonal changes

More severe over Antarctica than the Arctic

Consequences

Effects of Ozone Depletion

Fig. 15-26, p. 377

What Can You Do?

Fig. 15-27, p. 378

Reversing Ozone Depletion

Stop producing ozone-depleting chemicals

Slow recovery

Montreal Protocol

Copenhagen Protocol

International cooperation

Animation: pH Scale

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Animation: Half-Life

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Animation: Nitrogen Cycle

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Animation: Sulfur Cycle

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Animation: Thermal Invasion and Smog

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Animation: Formation of Photochemical Smog

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Animation: Acid Deposition

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Animation: Effects of Air Pollution in Forests

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Animation: Climate and Ocean Currents Map

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Animation: Air Circulation and Climate

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Animation: Air Circulation

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Animation: Greenhouse Effect

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Animation: Increasing Greenhouse Gases

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Animation: El Nino Southern Oscillation

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Animation: Coastal Breezes

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Animation: Upwelling Along Western Coasts

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Animation: Humans Affect Biodiversity

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Animation: Habitat Loss and Fragmentation

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Animation: How CFCs Destroy Ozone

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Video: Air Pollution in China

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Video: Clean Air Act

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Video: China Computer Waste

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Video: U.S. Earth Summit

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Video: Melting Ice

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Video: Global Warming

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Video: Dinosaur Discovery

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Video: Desertification in China

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Video: Ozone Layer Depletion

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