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 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 –Less evaporation because little surface water –heat released when fuels are burned –tall buildings block wind –air pollutants absorb long wavelength radiation

Climate Change Changes in solar radiation tectonic activity changes in Earth’s orbit around the sun catastrophic events changes in atmospheric composition

Solar radiation Fig 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 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 –release particulate matter into the atmosphere –cause cooling –major meteor impact 65 mya –Alvarez Hypothesis Volcanic eruptions –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 –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