Chapter 9: Air: Climate and Pollution

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Chapter 9 Topics• 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

• 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

Ocean Currents

• Warm an cold ocean currents influence life on earth

• Result from surface winds, water density (depending on the temperature and saltiness of water)

• Carry water north and south distributing heat• Eg. Gulf stream carries warm Caribbean

water to Europe.

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?

Milankovitchcycles

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