6 Warm up Wrap up 7 4, 6 Warm up Wrap up 1,3,7 Greenhouse effect.

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Greenhouse effect

Brainstorming

The menu for today6/26/2013

Greenhouse effectOzone depletionGlobal warming

Weather patterns changing

78% nitrogen

20.6% oxygen

< 1% argon

0.4% water vapor

0.036% carbon dioxide

traces gases:Ne, He, Kr, H, O3

Methane, Nitrous Oxide

Greenhouse effect

Heat from the planets surface is absorbed by greenhouse gases, and is re-radiated in all directions

Selected Greenhouse

Gases

• Carbon Dioxide (CO2) – Source: Fossil fuel burning,

deforestation Anthropogenic increase: 30% Average atmospheric residence

time: 500 years

Selected Greenhouse

Gases

Methane (CH4) – Source: Rice cultivation, cattle &

sheep ranching, decay from landfills, mining

Anthropogenic increase: 145% Average atmospheric residence

time: 7-10 years

Selected Greenhouse

Gases

Nitrous oxide (N2O) – Source: Industry and agriculture

(fertilizers) Anthropogenic increase: 15% Average atmospheric residence

time: 140-190 years

Water VaporSelected

Greenhouse Gases

1. Shorter, highEnergy wavelengths Hit the earthsSurface

2. Incoming energy Is converted to heat

3. Longer, infraredWavelengths hitGreenhouse gasMolecules in theatmosphere

4. Greenhouse gasMolecules in theAtmosphere emitInfrared radiationBack towards earth

Summary

Greenhouse gases absorb infrared radiation and prevent it from escaping to space.

Carbon dioxide, methane, and nitrous oxide are very good

at capturing energy at wavelengths that other compounds

miss

ozone layer layer in Earth's atmosphere which absorbs most of the Sun's UV radiation

Ozone depletion a steady decline of about 4% per decade in the total volume of ozone in Earth's stratosphere (the ozone layer

ozone-depleting substances. CFCs, freons, halons

refrigerants, propellants (in aerosol applications), and solvents

Global warming the rise in the average temperature of Earth's atmosphere and oceans since the late 19th century and its projected continuation

Who has been paying attentionWHY?

Greenhouse Effect & Global Warming

• The “greenhouse effect” & global warming are not the same thing. – Global warming refers to a rise in the

temperature of the surface of the earth • An increase in the concentration of

greenhouse gases leads to an increase in the magnitude of the greenhouse effect. (Called enhanced greenhouse effect) – This results is global warming

Effects of global warming

Effects of global warming

Melting of ice/North and south pole change salt and fresh water variables