The Greenhouse Effect (8.6)

The Greenhouse Effect How does the climate system trap

energy to keep Earth warm? Gases in the atmosphere absorbed the IR

radiation emmitted by the earth and radiate it in all directions

Half gets sent back to earth to warm it up even more

The energy trapping process is called the greenhouse effect!

Greenhouse gasesMAJOR Carbon Dioxide

0.0385% of atmosphere (not a lot!) Causes ¼ of natural greenhouse effect Natural sources: volcanoes, burning organic matter, cell respiration

Water Vapour 2/3 of Earth’s natural greenhouse effect Amount varies from very little to 4% of atmosphere

MINOR Methane

Much less in atmosphere but 23x more effective than CO2 Natural sources: plant decomposition

Ozone Acts as greenhouse gas in troposphere

Nitrous Oxide Very little in atmosphere but 300x more effective than CO2 Natural Source: reactions of bacteria in soil

Videos! https://www.youtube.com/watch?v=Hi3E

Res0h84

http://ed.ted.com/lessons/climate-change-earth-s-giant-game-of-tetris-joss-fong#review

Energy Transfer within the climate system (8.8)

Energy Transfer in the Atmosphere

Convection current: Air near the equator warms up, rises and

spreads and then the cooler air drops and the cycle repeats

This causes winds that are predictable Prevailing winds help push warm air and

water to the poles Another factor in determining climate

zones!

Energy Transfer in the Oceans

Thermohaline circulation: At the poles, surface water freezes and leaves

saltier colder water which is more dense and sinks to the bottom

This allows warmer surface water from the equator to flow to the poles

Acts as a conveyer belt carrying water from the equator to the poles

Ocean currents can also be caused by winds Have a strong effect on climates of land nearby

Warm water warm moist air warms land rain Cold water cool dry air cools land desert

https://www.youtube.com/watch?v=ajQ3hm5JidU

HOMEWORK! Read pg. 338-347 Questions:

Pg. 342 #1-3, 6 Pg. 347 #1, 3, 6-7