The Chemistry of Global Warming
Earth Atm. @ 1x had 1000x more CO2
Where did it go?
Dissolved in oceans
Fixed as CaCO3 - limestone
SUN < 25-30% - ?
Early Pollution was O2!
6CO2 + 6H2O ---> C6H12O6 + 6O2
Photosynthesis* - chlorophyll used Sun E to change CO2 & H2O into Glucose & O2 (*note to future teachers - this is in every 3-6 curriculum)
Temperature & CO2 content have changed over time
Factors that caused temp. change
1) Fluctuations in Earths Orbit
b) angle of incidence
2) Terrestrial events
b) cloud cover
c) airborne dust
d) CO2 & CH4 conc.
These feedback mechanisms are poorly understood.
Earths Energy Balance(OH & fig 3.2)
Greenhouse Effect - my nifty drawing
84 % of heat reradiated is absorbed by the atmo.
If we release/increase gases? (fig. 3.3)
Maximize distance between e-
H :C: H
Lewis Dot Structure - do not show actual shape ( geometry) tetrahedron
1)Electron pairs in a molecule are usually arranged in such a way that they are as far from each other as possible.
2) Bonding pairs have less space requirements than non bonding.
H2O ---> H:O: H
-140.5- .. ..
.. .. 1800
Why all this fuss about shape?
IR radiation does NOT have enough E to break bonds but it will cause a molecule to vibrate.
Molecular structure determines
type of vibration
each vibration has characteristics Set of E - Levels \diff. mol. absorb E @ diff l.
Amount of E required varies with
1. Nature of motion
4. mass of atom
Fig 3.5 & 3.6 (p.84-85)
THE CARBON CYCLE (fig 3.8)
Question this chart! .5%.
photosynthesis - 110/203 = 54%
the other 46 % is dissolved in oceans, animal shells, rocks
Another dynamic, steady state system!
How is it returned?
Death and Decay ---> CO2
Broken Down ---> CO2
Animals ---> CO2
volcanoes, weathering ---> ?
Carbon - 12 (Carbon-12
C-12 = 98.9%
C-14 - 1 x 1012 --> radioactive
But how would we measure .1 mg?
.1 mg---> 1x10-4g ---> 5x1018 atoms C
not our scales!
is 6.02x1023 or 1 mole
(note examples p. 91 - 93)
1 C + 1 O2 ---> 1 CO2
1 mole C x 12.0 g/mole C = 12g
+ 2 mole O x 16.0 g/mole O = 32 g
molar mass of CO2 is 44 g
molecular wt. - old term
2. meteorology MODELS
in Ocean Temp. causes aØ CO2 solubility which causes an in CO2 atoms which Ocean temp. so phytoplankton , which Ø CO2 in the atmo. so that there is a in CO2 fixing
\ Ø in atmo temp, which Ø ocean temp
WAIT A MINUTE !!!! BUT YOU SAID ...
global temp, evap, transpiration, clouds which reflect sunlight which lead to Ø in global temp or in global temp b/c H2O greenhouse gas
What to do? What to do?
1. Study & (maybe forever) wait
2. Do SOMETHING!!! The Chicken Littles
3. What do you want from life? Live with it
My View (happens
to coincide w/text)
1. Careful study
2. Extensive monitoring - improves reliability
3. Appropriate technology
4. EDUCATED, INFORMED & RESPONSIBLE public
and yet you can never be absolutely