ENVIRONMENTAL SCIENCE

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ENVIRONMENTAL SCIENCE
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CHAPTER 15Air Pollution, Climate Change, and
Ozone Depletion
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Core Case Study South Asias Massive Brown Cloud
(1)

• Asian Brown Cloud
• India to Bangladesh to Chinas Pacific coast
• Pollutants from fires, cars, industry
• Skies permanently gray or brown

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Core Case Study South Asias 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

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15-1 What is the Nature of the Atmosphere?

• Concept 15-1 The two innermost layers of the
  atmosphere are the troposphere, which supports
  life, and the stratosphere, which contains the
  protective ozone layer.

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Earths Atmosphere

• Troposphere
• 5-11 miles above earths surface
• 7580 earths air mass
• 78 N2, 21 O2
• Weather and climate
• Stratosphere
• Ozone layer

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

• Concept 15-2A 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.

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

• Concept 15-2B 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.

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Outdoor Air Pollution

• What is air pollution?
• Stationary and mobile sources
• Primary pollutants
• Secondary pollutants

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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)

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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

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Photochemical Smog

• Photochemical reactions
• Photochemical smog
• Brown-air smog
• Sources
• Health effects
• Urban areas

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Natural Factors That Reduce Air Pollution

• Particles heavier than air
• Rain and snow
• Salty sea spray from oceans
• Winds
• Chemical reactions

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Natural Factors That Increase Air Pollution

• Urban buildings
• Hills and mountains
• High temperatures
• VOC emissions from certain trees and plants
• Grasshopper effect
• Temperature inversions

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Acid Deposition

• Sulfur dioxides and nitrogen oxides
• Wet and dry deposition
• Acid rain
• Regional air pollution
• Midwest coal-burning power plants
• Prevailing winds

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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

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Indoor Air Pollution

• 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

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Major Indoor Air Pollutants

• Tobacco smoke
• Formaldehyde
• Radioactive radon-222 gas
• Very small particles

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Air Pollution and the Human Respiratory System

• Natural protective system
• Lung cancer, chronic bronchitis, emphysema,
  asthma
• Premature deaths
• Air pollution kills 2.4 million people
  prematurely every year

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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.

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U.S. Outdoor Air Pollution Control Laws

• Clean Air Acts
• Air-quality standards for 6 major pollutants
• Levels of these 6 pollutants have fallen
  dramatically between 1980 and 2008

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Improving Air Pollution Laws (1)

• Emphasize pollution prevention
• Increase fuel economy standards
• Regulate emissions from two-cycle engines
• Regulate ultra-fine particles

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Improving Air Pollution Laws (2)

• Increase regulations at airports
• Decrease urban ozone
• Increase regulations for indoor air pollution
• Better enforcement of Clean Air Act

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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 being gradually lowered

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15-4 How Might the Earths Climate Change in the
Future?

• Concept 15-4 Considerable scientific evidence
  indicates that emissions of greenhouse gases into
  the earths atmosphere from human activities will
  lead to significant climate change during this
  century.

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Past Climate Changes

• Glacial and interglacial periods
• Global cooling and global warming
• Measurement of past temperature changes
• Rocks and fossils
• Ice cores from glaciers
• Tree rings
• Historical measurements since 1861

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The Greenhouse Effect

• Earths natural greenhouse effect
• Natural greenhouse gases
• Water vapor (H2O)
• Carbon dioxide (CO2)
• Methane (CH4)
• Nitrous Oxide (N2O)

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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

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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 48 inches

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CO2 Is the Major Culprit

• 1850 285 ppm
• 2009 388 ppm
• Over 450 ppm is tipping point
• 350 ppm as intermediate goal

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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

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What Role for Oceans in Climate Change?

• Absorb CO2
• CO2 solubility decreases with increasing
  temperature
• Upper ocean getting warmer

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15-5 What Are Some Possible Effects of a
Projected Climate Change?

• Concept 15-5 The projected change in the earths
  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.

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Potential Severe Consequences

• Rapid projected temperature increase
• 2 Cº inevitable
• 4 Cº possible
• Effects will last for at least 1,000 years

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Harmful Effects of Global Warming (1)

• Excessive heat
• Drought
• Ice and snow melt
• Rising sea levels
• Extreme weather

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Harmful Effects of Global Warming (2)

• Threat to biodiversity
• Food production may decline
• Change location of agricultural crops
• Threats to human health

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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.

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Options to Deal with Climate Change

• Two approaches
• Drastically reduce greenhouse gas emissions
• Develop strategies to reduce its harmful effects
• Mix both approaches
• Governments beginning to act

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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

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Reducing the Threat of Climate Change (2)

• Transfer appropriate technology to developing
  countries
• Reduce deforestation
• Sustainable agriculture and forestry
• Reduce poverty
• Slow population growth

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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

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Science Focus Is Capturing and Storing CO2 the
Answer? (1)

• Global tree planting
• Restore wetlands
• Plant fast-growing perennials

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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

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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

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Government Roles in Reducing the Threat of
Climate Change (2)

• International climate negotiations
• Kyoto Protocol
• Act locally
• Costa Rica
• U.S. states
• Large corporations
• Colleges and universities

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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 earths 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.

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Human Impact on the Ozone Layer

• Location and purpose of the ozone layer
• Blocks UV-A and UV-B
• Seasonal and long-term depletion of ozone
• Threat to humans, animals, plants
• Causes chlorofluorocarbons (CFCs)

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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

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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

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Reversing Ozone Depletion

• Stop producing ozone-depleting chemicals
• Slow recovery
• Montreal Protocol
• Copenhagen Protocol
• International cooperation

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Three Big Ideas from This Chapter - 1

• All countries need to step up efforts to control
  and prevent outdoor and indoor air pollution.

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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.

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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 earths surface.