Download Climate and Air Pollution

Chapter 9:
Air: Climate and Pollution
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Chapter 9 Topics
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The Atmosphere and Climate
Climate Change
Climate and Air Pollution
Interactions Between Climate Processes and
Air Pollution
Effects of Air Pollution
Air Pollution Control
Clean Air Legislation
Current Conditions and Future Prospects
Part 1: The Atmosphere and Climate
The
atmosphere
has four
distinct zones
of contrasting
temperature.
Energy and the "Greenhouse Effect"
Convection and Atmospheric Pressure
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Evaporation
Latent heat
Condensation
Convection
currents
• Air pressure
differences
• Coriolis effect
Tornadoes are
local cyclonic
storms caused
by rapid
mixing of cold,
dry air and
warm, wet air.
Seasonal Winds and Monsoons
Part 2: Climate Change
• The Earth's climate changes, often in
short or long cycles.
• Ice ages, droughts
• Milankovitch cycles, orbital shifts, sunspot
cycles, ocean currents
• Climate does not necessarily change
gradually - meteor impacts, methane
releases?
Milankovitch
cycles
Human-Caused Global Climate Change
• Global mean surface temperatures have
increased about 0.9 degrees F over the
past 100 years.
• Much of this change is now understood
to result from a number of human
activities, primarily the burning of oil, gas,
and coal.
• CO2 levels are increasing 0.5% a year.
Carbon dioxide levels are increasing
Possible Implications of and Debate
Surrounding Global Warming
• More heat waves
• More extreme storm
activity
• Changes in rainfall,
snowfall patterns
• Ecosystem effects
• Higher sea levels
• More disease
• Winners: Siberia,
Scandinavia
• Losers: most of U.S.
(particularly SE;
Washington may be
nicer), island states
• Skepticism
• Kyoto Protocol
Part 3: Climate and Air Pollution
• Over the past 20 years,
developed countries
have made progress in
improving air quality.
• Unfortunately, air quality
in the developing world
has been getting worse.
Major Air Pollutants: Problems
• Sulfur dioxide - acid rain, health damage,
visibility reduction
• Nitrogen oxides - acid rain, eutrophication,
growth of weedy species
• Carbon monoxide - inhibited respiration
• Lead and mercury - neurological damage
• Chlorofluorocarbons - ozone depletion
• Particulate matter - lung damage, cancer
• Volatile organic compounds - CO, CO2
production in the atmosphere
Indoor Air Pollution
• Smoking - diseases
related to smoking
responsible for 20%
of deaths in the U.S.
• In less-developed
countries, poorly
ventilated heating
and cooking fires
represent the
greatest source of
indoor air pollution.
Part 4: Interactions Between
Climate Processes and Air
Pollution
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Long-range transport
Stratospheric ozone depletion
Montreal Protocol - 1987
Temperature inversions
Heat islands, dust domes
Part 5: Effects of Air Pollution
• Human health
• Plant pathology
• Visibility
reduction
• Acid deposition
Ecosystem damage caused by sulfur dioxide
emissions and acid rain.
Acid Precipitation, 2000
Part 6: Air Pollution Control
• Early approach: "Dilution is the solution
to pollution"
• Particulate removal - air filters
• Sulfur removal - scrubbers
• Nitrogen oxide reduction - catalytic
converters
• Hydrocarbon controls - afterburners
Part 7: Clean Air Legislation
• Clean Air Act of 1963
• Clean Air Act of 1970 - primary and
secondary standards for ambient air
quality
• 1990 update - significant amendments
• Controversy
• California - additional pollution control
plans
Some Good News: U.S. Trends