 How are we affected by our atmosphere?  How is our atmosphere affected by us?

Absorption of electromagnetic radiation

Layer heights are NOT TO SCALE

Where our stuff is…

 Certain gases trap heat energy from the sun in earth’s atmosphere  They act like a greenhouse, keeping earth warm  Natural greenhouse effect keeps earth warm and habitable  Major natural greenhouse gases: carbon dioxide, methane, water vapor, nitric oxide

World population: 7 billion US population: 300 million, or ~4%, but we emit 20% of C)

 1. Examine the effect of our carbon dioxide output on global climate change with computer models  Complete a “carbon footprint” profile with your own family compared to others  Graph with Excel  Common task!

The Earth's ozone layer protects all life from the sun's harmful radiation – UVB - but human activities have damaged this shield Ozone – O 3 - is blue and has a strong odor Normal oxygen - O 2 - is colorless and odorless

Human impact:  CFCs (found in refrigerants, solvents, foam blowing agents) damage ozone layer  CFCs banned in in US in 1970s  Jet exhaust produces nitric oxide, which also breaks down ozone The good news:  Natural ozone production process will heal the ozone layer in about 50 years