Structure of the atmosphere
 Heat-trapping gases
 The greenhouse effect

Earth’s atmosphere is 372 miles thick (small
compared to the size of the earth)
 Divided into four layers based on
temperature (troposphere, tropopause,
stratosphere, mesosphere, thermosphere,)
 Weather happens in troposphere = layer
closest to the earth
 Troposphere is the densest layer, holds
80% of water vapor

OZONE
http://eo.ucar.edu/staff/rrussell/atmosphere/images/mesosphere_diagram_big.jpg
HIPPO

Atmosphere = the thin layer of gases that surrounds
Earth
› Absorbs radiation and moderates climate
› Transports and recycles water and nutrients
› 78% nitrogen gas, 21% oxygen gas, 1% other gases
› Its four layers differ in temperature, density and
composition

Minute concentrations of permanent (remain at stable
concentrations) and variable gases (varying
concentrations)

Human activity is changing the amounts of some gases

Turn to a partner and make a list of
greenhouse gases
CO2 GAS
 H2O VAPOR
 CH4 GAS

carbon dioxide
water vapor (humidity)
methane
Gas
Global
Warming Factor
Concentration
parts (ppb*)
Carbon Dioxide CO2
1
379,000
Methane
CH4
21
1,760
Nitrous Oxide
N2O
310
320
Chlorofluorocarbons
CFCs
5,000 to 14,000
Less than 1
Ppb = parts per billion
http://www.ecoslopes.com/wpcontent/uploads/2009/03/greenhouseeffect-solutions-300x225.jpg
http://www.sciencebuzz.org/sites/all/files_static/global_warming/greenhouse_effect.gif
The atmosphere = without it, the Earth’s temperature
would be much colder
Earth’s atmosphere, clouds, land, ice, and water absorb 70%
of incoming solar radiation
W/m2
Turn to your neighbor and spend 2 minutes explaining what you
npr video clip on carbon
CO2 causes temperatures to rise
Over the past 425,000 years, cool periods have coincided with times when the CO2 concentration
in the atmosphere was lower. When there is less CO2 in the atmosphere, the greenhouse effect is
reduced and the world cools.
The blue and red line indicates the variation in average global temperature compared with the
1961–1990 average. The green line shows the concentration of CO2 in the atmosphere. (Pay close
attention to the right-hand edge of the graph.)
This graph shows four eras when the world was cooler than it is today. These are separated by brief
warm periods, like the one we are now in.
During respiration, energy stored in a glucose is
used to perform cellular activities.
sugar + oxygen CO2 + water + energy (to do
work)
During photosynthesis, energy from the sun
converts carbon dioxide and water into
glucose, an energy source. Oxygen is a
byproduct of this process.
water + CO2 + solar energy sugar + oxygen
Student represents
Ball of yarn represents
Sources and sinks
Carbon
RULES
No one can get the ball twice
until everyone has had it at
least once.
Where it started
Where it went
How it got there
Write a short story from the perspective of
a carbon atom as it travels through the
carbon cycle. List the places you travel
and how you move from place to place
until you return to where you started.