Transcript Climate Change and Air Pollution

Climate Change and Air
Pollution
Read
• Chapters 17 and 18
Climate Change
• Natural Factors
• Human Induced
Global Air Circulation
• Hadley Cell
• 3 cells (show cells)
• Doldrums
– NE Trades
• Horse Latitudes
– Westerlies
– Polar Easterlies
• Coriolis Effect
Factors that Determine Climate
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Latitude
Pressure and wind belts
Altitude
Oceans
– transport heat
– moderate climate
• Mountain Ranges
• Geographic Position
Climate Zones of Earth
• Koppen Climate Classification
– seasonal variation in temperature
– precipitation
Urban Heat Island Effect
• Why are cities warmer
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Less evaporation because little surface water
heat released when fuels are burned
tall buildings block wind
air pollutants absorb long wavelength radiation
Climate Change
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Changes in solar radiation
tectonic activity
changes in Earth’s orbit around the sun
catastrophic events
changes in atmospheric composition
Solar radiation
• Fig. 17-22
• Solar radiation varies
• debatable correlation between duraiton of
sunspot cycles and global temperature
Tectonic Activity: Long term effects
• two processes cause climate change
– continental migration
• 250 million years ago (Permian)
• Continents together and over the South Pole
• Permian Glaciation
– ended when Pangea broke up
– mountain building
• global cooling in the past 40 million years coincides
with the formation of the Himalayas and the North
American Cordilleran
Changes in Earth’s Orbit Around the Sun
Fig. 17-24
• Eccentricity
– varies on 100,000 year cycle
• Tilt
– currently 23.5 degrees
– varies by 1.5 degrees on a 41,000 yr cycle
• Precession
– wobble of the axis
– varies on a 23,000 yr cycle
• Milankovitch Cycle
Catastrophic Events
• Meteor Impact
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release particulate matter into the atmosphere
cause cooling
major meteor impact 65 mya
Alvarez Hypothesis
• Volcanic eruptions
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also release particulate matter
1815 Tambora-largest historic eruption
1816 one of the coldest years in recorded history
crop failures + Napoleonic Wars led to famine in Europe
Change in composition
• Increase in greenhouse gases
– carbon dioxide
– methane
– CFC
Air Pollution
• Primary Air Pollutants
– gases and particles released during combustion
and manufacturing
• Secondary Air Pollutants
– generated by reaction of primary pollutants in
the atmosphere
• smog
• acid precipitation
Smog
• Brownish-yellow haze
• auto exhaust reactions with air in the
presence of sunlight to form
• Ozone in the troposphere
– irritates membranes in the respiratory system causing
loss of lung function
– increases susceptibility to lung and heart disease
– suspected carcinogen
Inversions
• Cap of warm air over cold air
• polluted air can’t rise and mix
Warfare and the Atmosphere
• Fires
– Kuwaiti oil fields - Persian Gulf War
• Nuclear
– Nuclear winter
– Acid and Chemical Precipitation
– Destruction of ozone layer
• Nuclear Winter
– pulverized soil is blasted into the stratosphere
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along with soot from fires
blocks out 95% of solar radiation
temperature in the No. Hemi. Drop to -25 C even in the summer
deaths due to freezing and starvation
• Acid and Chemical Precipitation
– from industrial, agricultural and domestic chemicals blasted into the
atmosphere
• Ozone distruction
– heat from the blast converts atmospheric nitrogen to nitrogen oxides and
these compounds would destroy the ozone layer