Air Pollution, Climate Change, and Ozone Depletion

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Air Pollution, Climate Change, and Ozone Depletion

• Chapter 12

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12-1 What Is the Nature of the Atmosphere?

• Concept 12-1 The atmosphere is structured in
  layers, including the troposphere, which supports
  life, and the stratosphere, which contains the
  protective ozone layer.

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The Atmosphere Consists of Several Layers (1)

• Atmosphere varies in
• Density
• Atmospheric pressure

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The Atmosphere Consists of Several Layers (2)

• Troposphere
• 7580 of the earths air mass
• Closet to the earth's surface
• Chemical composition of air
• Rising and falling air currents weather and
  climate
• Involved in chemical cycling

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The Stratosphere Is Our Global Sunscreen

• Stratosphere
• Similar composition to the troposphere, with 2
  exceptions
• Much less water
• O3, ozone layer, filters UV
• Location

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Earth Has Many Different Climates (1)

• Weather
• Climate
• Air circulation in lower atmosphere due to
• Uneven heating of the earths surface by the sun
• Rotation of the earth on its axis
• Properties of air, water, and land

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Earth Has Many Different Climates (2)

• Currents
• Prevailing winds
• Earths rotation
• Redistribution of heat from the sun
• Link between air circulation, ocean currents, and
  biomes

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Greenhouse Gases Warm the Lower Atmosphere

• Greenhouse gases
• H2O
• CO2
• CH4
• N2O
• Greenhouse effect
• Human-enhanced global warming

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12-2 What Are the Major Outdoor Pollution
Problems?

• Concept 12-2 Pollutants mix in the air to form
  industrial smog, resulting mostly from burning
  coal, and photochemical smog, caused by motor
  vehicle, industrial, and power plant emissions.

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Air Pollution Comes from Natural and Human
Sources (1)

• Air pollution
• Natural sources
• Dust blown by wind
• Pollutants from wildfires and volcanoes
• Volatile organics released by plants
• Withdrawing groundwater

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Air Pollution Comes from Natural and Human
Sources (2)

• Human sources mostly in industrialized and/or
  urban areas
• Stationary sources
• Mobile sources

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Air Pollution Comes from Natural and Human
Sources (3)

• Primary pollutants
• Secondary pollutants
• Air quality improving in developed countries
• Much more needs to be done in developing
  countries
• Indoor pollution big threat to the poor

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Burning Coal Produces Industrial Smog

• Chemical composition of industrial smog
• Reduction of this smog in urban cities of the
  United States
• China and smog
• Human deaths

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Sunlight Plus Cars Equals Photochemical Smog

• Photochemical Smog
• Chemical composition
• Sources
• VOCs NO2 Heat Sunlight yields
• Ground level O3 and other photochemical oxidants
• Aldehydes
• Other secondary pollutants
• Human health and environmental impact

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Several Factors Can Decrease or Increase Outdoor
Air Pollution (1)

• Outdoor air pollution may be decreased by
• Settling of particles due to gravity
• Rain and snow
• Salty sea spray from the ocean
• Winds
• Chemical reactions

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Several Factors Can Decrease or Increase Outdoor
Air Pollution (2)

• Outdoor air pollution may be increased by
• Urban buildings
• Hills and mountains
• High temperatures
• Emissions of VOCs from certain trees and plants
• Grasshopper effect
• Temperature inversions

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12-3 What Is Acid Deposition and Why Is It a
Problem?

• Concept 12-3 Acid deposition is caused mainly by
  coal-burning power plant and motor vehicle
  emissions in some regions, it threatens human
  health, aquatic life and ecosystems, forests, and
  human-built structures.

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Acid Disposition Is a Serious Regional Air
Pollution Problem

• Acid deposition, acid rain
• Formation
• Local versus regional problems
• Effects of prevailing winds
• Buffers
• Where is the worst acid deposition?

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Acid Deposition Has a Number of Harmful Effects
(1)

• Human respiratory disorders
• Aquatic ecosystems affected
• Release of toxic metals

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Acid Deposition Has a Number of Harmful Effects
(2)

• Leaching of soil nutrients
• Loss of crops and trees
• Damage to buildings, statues, and monuments

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12-4 Why Is Indoor Air Pollution a Major Problem?

• Concept 12-4 The major indoor air pollutants are
  smoke and soot from wood and coal fires (mostly
  in developing countries) and chemicals used in
  building materials and products, all of which
  threaten human health.

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Indoor Air Pollution Is a Serious Problem (1)

• Developing countries
• Indoor burning
• Poor suffer the greatest risk
• Developed countries
• Indoor air pollution is greater than outdoor air
  pollution

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Indoor Air Pollution Is a Serious Problem (2)

• Why?
• 11 of the common air pollutants higher inside
  than outside
• Greater in vehicles than outside
• Health risks magnified people spend 7098 of
  their time is indoors

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Indoor Air Pollution Is a Serious Problem (3)

• Who are at greatest risk from indoor air
  pollution?
• Children under 5 and the elderly
• Sick
• Pregnant women
• People with respiratory disorders or heart
  problems
• Smokers
• Factory workers

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Indoor Air Pollution Is a Serious Problem (4)

• Four most dangerous indoor air pollutants
• Tobacco smoke
• Formaldehyde
• Radioactive radon-222 gas
• Very small particles
• Sources of these pollutants
• Human health risks

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Indoor Air Pollution Is a Serious Problem (5)

• Other possible indoor air pollutants
• Pesticide residue
• Pb particles
• Living organisms and their excrements
• E.g., Dust mites and cockroach droppings
• Airborne spores of molds and mildews
• Sick-building syndrome

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Case Study Radioactive Radon Gas

• Sources
• Human health risks
• Testing for radon
• Correcting a radon problem

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Your Bodys Natural Defenses against Air
Pollution Can Be Overwhelmed

• Respiratory system protection from air pollutants
• Role of cilia, mucus, sneezing, and coughing
• Effect of smoking and prolonged air pollution
  exposure
• Chronic bronchitis
• Emphysema

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Air Pollution Is a Big Killer

• 3 Million deaths per year world-wide
• Mostly in Asia
• Main causes
• EPA proposed stricter emission standards for
  diesel-powered vehicles
• Link between international trade and air
  pollution
• Cargo ships and pollution

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12-5 How Should We Deal with Air Pollution?

• Concept 12-5 Legal, economic, and technological
  tools can help to clean up air pollution, but
  much greater emphasis should be focused on
  preventing air pollution.

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Laws and Regulations Can Reduce Outdoor Air
Pollution (1)

• United States
• Clean Air Acts 1970, 1977, and 1990
• EPA
• National ambient air quality standards (NAAQs)
  for 6 outdoor criteria pollutants
• National emission standards for 188 hazardous air
  pollutants (HAPs)
• Toxic Release Inventory (TRI)

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Laws and Regulations Can Reduce Outdoor Air
Pollution (2)

• Good news in U.S.
• Decrease in emissions
• Use of low-sulfur diesel fuel
• Cuts pollution
• Developing countries
• More air pollution

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Case Study Lead Can Be a Highly Toxic Pollutant
(1)

• Does not break down in the environment
• Sources
• Human health and environmental impact
• Most vulnerable

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Case Study Lead Can Be a Highly Toxic Pollutant
(2)

• Reduction of lead (Pb)
• Unleaded gasoline
• Unleaded paint
• Still problems
• 2007 toys with Pb paint recalled
• Global ban on lead in gasoline and paint

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Case Study U.S. Air Pollution Laws Can Be
Improved (1)

• Rely on cleanup more than prevention of pollution
• Raise fuel-efficiency for cars, SUVs, and light
  trucks
• Better regulation of emissions of motorcycles and
  two-cycle gasoline engines
• Regulate air pollution for oceangoing ships in
  American ports

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Case Study U.S. Air Pollution Laws Can Be
Improved (2)

• Why are airports exempt from many regulations?
• Regulate greenhouse gas emissions
• Ultrafine particles are not regulated
• Urban O3 levels too high

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Case Study U.S. Air Pollution Laws Can Be
Improved (3)

• What about indoor air pollution?
• Better enforcement of the Clean Air Acts
• Is intense pressure needed from citizens to make
  improvements?

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We Can Use the Marketplace to Reduce Outdoor Air
Pollution

• Emission trading or cap-and-trade program
• Mixed reactions to program
• SO2 emissions down significantly
• NO2 will be tried in the future

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There Are Many Ways to Reduce Outdoor Air
Pollution

• 1980 2006
• SO2 emissions from U.S. electric power plants
  decreased by 66
• NOx emissions by 41
• Particulate emissions by 28
• Older plants not governed by the same regulations
• New cars have better emissions

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Reducing Indoor Air Pollution Should Be a
Priority

• Greater threat to human health than outdoor
  pollution
• What can be done?
• Prevention
• Cleanup

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We Need to Put More Emphasis on Pollution
Prevention

• Output approaches
• New shift to preventing outdoor and indoor
  pollution
• Pressure from citizens

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12-6 How Might the Earths Temperature and
Climate Change in the Future?

• Concept 12-6A Evidence indicates that the
  earths atmosphere is warming, mostly because of
  human activities, and that this will lead to
  significant climate change during this century.
• Concept 12-6B The projected rapid change in the
  atmospheres temperature could have severe and
  long-lasting consequences, including increased
  drought and floods, shifts in locations of
  agriculture and wildlife habitats, and rising sea
  levels.

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Global Warming and Global Cooling Are Not New (1)

• Over the past 4.7 billion years the climate has
  been altered by
• Volcanic emissions
• Changes in solar input
• Movement of the continents
• Impacts by meteors
• Over the past 900,000 years
• Glacial and interglacial periods

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Global Warming and Global Cooling Are Not New (2)

• Over the past 10,000 years
• Interglacial period
• Over the past 1,000 years
• Temperature stable
• Over the past 100 years
• Temperature changes methods of determination

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Human Activities Emit Large Quantities of
Greenhouses Gases (1)

• Since the Industrial Revolution
• CO2, CH4, and N2O emissions higher
• Main sources agriculture, deforestation, and
  burning of fossil fuels
• Correlation of rising CO2 and CH4 with rising
  global temperatures
• Countries with the largest CO2 emissions

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Human Activities Emit Large Quantities of
Greenhouses Gases (2)

• Per capita emissions of CO2
• Scientific and economic studies
• 2007 Field and Marland
• Tipping point
• 2008 Aufhammer and Carson
• Chinas CO2 emission growth may be underestimated
• Ice core analysis of air pollutants

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What Is the Scientific Consensus about Future
Temperature Change?

• Mathematical models used for predictions
• Global warming rapid rate
• Human factors are the major cause of temperature
  rise since 1950
• Human factors will become a greater risk factor

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Can the Oceans Save Us?

• Solubility of CO2 in ocean water
• Warmer oceans
• CO2 levels increasing acidity
• Effect on atmospheric levels of CO2
• Effect on coral reefs
• Antarcticas Southern Ocean and the North
  Atlantic Ocean
• Decrease in CO2 uptake
• Significance on global CO2 levels

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There Is Uncertainty about the Effects of Cloud
Cover on Global Warming

• Warmer temperatures create more clouds
• Thick, light-colored low altitude clouds
  decrease surface temperature
• Thin, cirrus clouds at high altitudes increase
  surface temperature
• Effect of jet entrails on climate temperature

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Outdoor Air Pollution Can Temporarily Slow Global
Warming

• Aerosol and soot pollutants
• Will not enhance or counteract projected global
  warming
• Fall back to the earth or are washed out of the
  lower atmosphere
• Reduction especially in developed countries

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Enhanced Global Warming Could Have Severe
Consequences (1)

• Tipping point and irreversible climate change
• Worst-case scenarios
• Ecosystems collapsing
• Low-lying cities flooded
• Wildfires in forests
• Prolonged droughts grasslands become dust bowls
• More destructive storms
• Glaciers shrinking rivers drying up

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Enhanced Global Warming Could Have Severe
Consequences (2)

• Accelerate global warming, lead to more drought
• Biodiversity will decrease
• NPP will decrease
• Dry climate ecosystems will increase
• Other effects of prolonged lack of water

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Enhanced Global Warming Could Have Severe
Consequences (3)

• Why will global warming be worse in the polar
  regions?
• Important climate role of floating sea ice
• Mountain glaciers affected by
• Average snowfall
• Average warm temperatures

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Enhanced Global Warming Could Have Severe
Consequences (4)

• Europes Alps
• Glaciers are disappearing
• South America
• Glaciers are disappearing
• Greenland
• Warmer temperatures

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Enhanced Global Warming Could Have Severe
Consequences (5)

• Expansion of warm water
• Melting of land-based ice
• What about Greenland?

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Enhanced Global Warming Could Have Severe
Consequences (6)

• Projected irreversible effect
• Degradation and loss of 1/3 of coastal estuaries,
  wetlands, and coral reefs
• Disruption of coastal fisheries
• Flooding of
• Low-lying barrier islands and coastal areas
• Agricultural lowlands and deltas
• Contamination of freshwater aquifers
• Submergence of low-lying islands in the Pacific
  and Indian Oceans and the Caribbean

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Enhanced Global Warming Could Have Severe
Consequences (7)

• Carbon present as CH4 in permafrost soils and
  lake bottoms
• 2004 Arctic Climate Impact Assessment
• 1020 of the permafrost might melt this century
• Effect on global warming

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Enhanced Global Warming Could Have Severe
Consequences (8)

• Heat waves and droughts in some areas
• Prolonged rains and flooding in other areas
• Will storms get worse?
• More studies needed
• Hurricanes Katrina and Rita

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Enhanced Global Warming Could Have Severe
Consequences (9)

• Most susceptible ecosystems
• Coral reefs
• Polar seas
• Coastal wetland
• High-elevation mountaintops
• Alpine and arctic tundra

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Enhanced Global Warming Could Have Severe
Consequences (10)

• What about
• Migratory animals
• Forests
• Which organisms could increase with global
  warming? Significance?
• Insects
• Fungi
• Microbes

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Enhanced Global Warming Could Have Severe
Consequences (11)

• Regions of farming may shift
• Decrease in tropical and subtropical areas
• Increase in northern latitudes
• Less productivity soil not as fertile
• Genetically engineered crops more tolerant to
  drought

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Enhanced Global Warming Could Have Severe
Consequences (12)

• Deaths from heat waves will increase
• Deaths from cold weather will decrease
• Higher temperatures can cause
• Increased flooding
• Increase in some forms of air pollution, more O3
• More insects, microbes, toxic molds, and fungi

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12-7 What Can We Do to Slow Climate Change?

• Concept 12-7 We can slow the rate of global
  warming and climate change by sharply reducing
  greenhouse gas emissions, increasing energy
  efficiency, relying more on renewable energy
  resources, and slowing population growth.

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What Are Our Options?

• Two approaches
• Drastically reduce the amount of greenhouse gas
  emissions
• Devise strategies to reduce the harmful effects
  of global warming
• Will we reach a political tipping point before we
  reach irreversible climate change tipping points?

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We Can Reduce the Threat of Climate Change (1)

• Input or prevention strategies
• Improve energy efficiency to reduce fossil fuel
  use
• Stop cutting down tropical forests
• Output strategy
• Capture and store CO2

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We Can Reduce the Threat of Climate Change (2)

• Output solutions
• Massive global tree planting how many?
• Wangari Maathai
• Great Wall of Trees China and Africa
• Plant fast-growing perennials on degraded land
• Capturing and storing CO2

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Is Capturing and Storing CO2 the Answer? (1)

• Carbon capture and storage (CCS)
• Several problems with this approach
• Power plants using CCS
• More expensive to build
• None exist
• Unproven technology
• Large inputs of energy to work
• Increasing CO2 emissions

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Is Capturing and Storing CO2 the Answer? (2)

• Problems with carbon capture and storage cont
• Promotes the continued use of coal (worlds
  dirtiest fuel)
• Effect of government subsidies and tax breaks
• Stored CO2 would have to remain sealed forever
  no leaking

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Governments Can Help to Reduce the Threat of
Climate Change

• Strictly regulate CO2 and CH4 as pollutants
• Cap-and-trade approach
• Increase subsidies to encourage use of
  energy-efficient technology
• Technology transfer

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Governments Can Enter into International Climate
Negotiations The Kyoto Protocol

• 1997 Treaty to slow climate change
• The Kyoto Protocol
• Reduce emissions of CO2, CH4, and N2O by 2012 to
  levels of 1990
• Trading greenhouse gas emissions among countries
• Not signed by the U.S.
• President G.W. Bushs reasons

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We Can Move Beyond the Kyoto Protocol

• 2004 Stewart and Wiener
• New treaty needed
• Should be led by the U.S.
• Include the developing countries
• Cap-and-trade emissions program
• Set up 10 year goals

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Some Governments, Corporations, and Individuals
Are Leading the Way (1)

• Costa Rica goal to be carbon neutral by 2030
• Norway aims to be carbon neutral by 2050
• China and India must change energy habits
• U.S. cities and states taking initiatives to
  reduce carbon emissions

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Some Governments, Corporations, and Individuals
Are Leading the Way (2)

• Major global companies reducing greenhouse gas
  emissions
• Alcoa
• DuPont
• IBM
• Toyota
• GE
• Wal-Mart
• Fluorescent light bulbs
• Auxiliary power units on truck fleets

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Some Governments, Corporations, and Individuals
Are Leading the Way (3)

• Colleges and universities reducing greenhouse gas
  emissions
• Oberlin College, Ohio, U.S.
• 25 Colleges in Pennsylvania, U.S.
• Yale University, CT, U.S.
• What is your carbon footprint?
• What can you do?

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We Can Prepare for Global Warming (1)

• Reduce greenhouse gas emissions as much as
  possible
• Move people from low-lying coastal areas
• Limit coastal building
• Remove hazardous material storage tanks away from
  the coast

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We Can Prepare for Global Warming (2)

• Genetically engineer crops more tolerant to
  drought
• Stockpile 15 years of key foods
• Waste less water
• Connect wildlife reserves with corridors

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12-8 How Have We Depleted Ozone in the
Stratosphere and What Can We Do?

• Concept 12-8A Widespread use of certain
  chemicals has reduced ozone levels in the
  stratosphere, which has allowed more harmful
  ultraviolet radiation to reach the earths
  surface.
• Concept 12-8B To reverse ozone depletion, we
  must stop producing ozone-depleting chemicals,
  and adhere to the international treaties that ban
  such chemicals.

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Human Activities Threaten the Ozone Layer

• Ozone Thinning
• Seasonal depletion in the stratosphere
• Antarctica and Arctic
• 1930 Midgely
• Discovered the first CFC
• 1984 Rowland and Molina
• CFCs were depleting O3
• Other ozone-depleting chemicals

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Science Focus Rowland and MolineA Scientific
Story of Courage and Persistence

• Research
• CFCs are persistent in the atmosphere
• Rise into the stratosphere over 11-20 years
• Break down under high-energy UV radiation
• Halogens produced accelerate the breakdown of O3
  to O2
• Each CFC molecule can last 65-385 years
• 1988 Dupont stopped producing CFCs
• 1995 Nobel Prize in chemistry

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We Can Reverse Stratospheric Ozone Depletion (1)

• Stop producing all ozone-depleting chemicals
• 60100 years of recovery of the O3 layer
• 1987 Montreal Protocol
• 1992 Copenhagen Protocol
• Ozone protocols prevention is the key

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We Can Reverse Stratospheric Ozone Depletion (2)

• Substitutes for CFCs are available
• More are being developed
• HCFC-22
• Substitute chemical
• May still be causing ozone depletion

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Ozone Levels over the Earths Poles Drop for a
Few Months Each Year

• Seasonal fluctuations
• Antarctic
• Arctic

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Why Should We Worry about Ozone Depletion?

• Damaging UV-A and UV-B radiation
• Increase eye cataracts and skin cancer
• Impair or destroy phytoplankton
• Significance?

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Science Focus Skin Cancer

• UV-B ionizing radiation
• Risk factors
• Children and adolescents
• Blistering sunburns
• Caucasians
• Tanning parlors