Thursday Nov 4th
SIT WITH YOUR GROUP TODAY!
Wrap up of Topic #13 Natural Climatic
Forcing (Volcanoes) then Introduction to
TOPIC #14 GLOBAL WARMING &
ANTHROPOGENIC FORCING
ANNOUNCEMENT:
The due date for RQ-7 is NEXT TUESDAY, Nov 9th
It will be posted tomorrow. Don’t FORGET!!!
NOTE: your last 3 RQ’s will all be due on TUESDAYS
instead of Thursdays
Where are
we now ?
SEMESTER WRAP-UP:
3 RQ’s (20 pts), Test #4 (25 pts), + Final Exam ( 100 pts)
+ clicker pts (10 individual 5 group)
TOTAL
OF
215 PTS
LEFT !!
Today!
5 pts
30 pts
20 pts
To be
posted this
weekend
Due last
week of
classes
CLICKER QUESTION:
Q1 In the film shown in class on
TUESDAY, what was Willie Nelson
promoting??
A – Solar power
B – Corn ethanol
C – Biodiesel
D – Hybrid trucks
Wrap up of TOPIC # 13
NATURAL CLIMATIC
FORCING:
Volcanic Eruptions
(pp 71-74)
How the Climatic Effect Occurs . . . .
through the ENERGY BALANCE
of course!
p 71
Mt Merapi
Latitude: 7°32'30"S
“Indonesia's Mount Merapi
erupted with renewed strength
on Wednesday, the fourth
eruption in eight days, forcing
authorities to move refugee
shelters further away from the
volcano, a vulcanology official
said.
The volcano, near Yogyakarta on
Java island, spewed clouds of
ash and gas 5 km (3 miles) into
the sky for more than an hour on
Wednesday, its biggest eruption
so far in the past 10 days.
How CLIMATICALLY EFFECTIVE
will this eruption be??
Q2 - Will it get into the stratosphere?
1 – YES
2 - NO, Probably not
Hint: See p 39
WHICH ERUPTIONS ARE THE
MOST CLIMATICALLY
EFFECTIVE?
• EXPLOSIVE
 high SULFUR content in
magma
 whose eruption clouds inject
into the STRATOSPHERE
 Low Latitude Eruptions
p 72
Q3 Why do you think Low Latitude eruptions
are more climatically effective and have more
of a effect?
1. Because the temperature is warmer in
tropical latitudes and hot air rises.
2. Because the Hadley Cell circulation can
distribute the volcanic aerosols into both
hemispheres if the eruption occurs near the
equator.
3. Because the tropopause is lower over Low
Latitudes and hence its easier for aerosols
to get injected into the stratosphere where
they will not be rained out.
Q3 Why do you think Low Latitude eruptions
are more climatically effective and have more
of a effect?
1. Because the temperature is warmer in
tropical latitudes and hot air rises.
2. Because the Hadley Cell circulation can
distribute the volcanic aerosols into both
hemispheres if the eruption occurs near the
equator.
3. Because the tropopause is lower over Low
Latitudes and hence its easier for aerosols
to get injected into the stratosphere where
they will not be rained out.
The GEOGRAPHIC
LOCATION of the
erupting volcano
influences the climatic
effectiveness of an
eruption because of
the General
Circulation of the
Atmosphere.
 Low latitude eruption
clouds get circulated more
broadly & in both
hemispheres
p 72
HOW DO REGIONAL CLIMATES
RESPOND TO AN EXPLOSIVE
ERUPTION?
In general, explosive eruptions warm
the stratosphere and cool the
troposphere, especially during the
summer season.
p 72
Major tropical eruption:
• Stratospheric heating is larger in
the tropics  enhanced pole-toequator temperature gradient, esp.
in winter.
N.H. winter  enhanced
gradient produces a stronger polar
vortex  stationary wave pattern
of tropospheric circulation
resulting in winter warming of NH
continents.
p 72
HOW MUCH TROPOSPHERIC
COOLING CAN OCCUR AND
HOW LONG DOES IT LAST?
 Individual large eruptions can result
in a 1-to-3 year cooling of average
surface temperatures of 0.3 to 0.7º C.
Tambora in 1815
Krakatau in 1883
Agung in 1963
El Chichon in 1982
p 72
HOW IMPORTANT IS EXPLOSIVE
VOLCANISM AS A FORCING
MECHANISM FOR PAST AND
FUTURE CLIMATE CHANGES?
 interdecadal climate change
(“Little Ice Age”)
 Individual years, such as 1816,
the “Year without a Summer” after the
eruption of Tambora in 1815
Link not always conclusive –
e.g., El Nino at same time, etc.
p 72
p 72
Typical Global Cooling Pattern
after a Volcanic Eruption
Average changes in temperature (based on 5 major eruptions)
COOLING
 Years before eruption
Years after eruption 
This graph shows the global mean temperature changes for
years before (-) and after a large eruption (at year zero)
p 72
Comparison Table of Eruptions
Latitude
How much
magma  how
big an eruption
How much
aerosol got into
each hemisphere
Estimated N.H.
temperature
change °C
Sulfur-rich
if high
H2SO4
p 73
G-4 ACTIVITY ON
VOLCANISM & CLIMATE
P.S. This is one of my
favorite questions to ask
on the FINAL EXAM!!!!
#1. List 4 reasons why Tambora in 1815
resulted in the largest GLOBAL cooling:
# 2. Give at least two reasons why the
eruption of Mt St. Helens was NOT a
very climatically effective eruption:
Write in the ERUPTIONS at top of page
Agung (1963)
Agung
Pinatubo (1991)
Pinatubo
El Chichon **
Pinatubo
Agung
El Chichon **
#3. Which levels
show a COOLING
and which
show a WARMING
immediately after the
eruption?
** NOTE: At the time of the
El Chichon eruption, there
was warming taking place
due to a strong El Nino,
hence the temperature
change after this eruption
shows a different response.
When ANSWERING
# 3 & #4 – focus on
Agung & Pinatubo
only
p 74
Write in the ERUPTIONS at top of page
Agung (1963)
Pinatubo (1991)
C
Agung
Pinatubo
El Chichon **
#4. Explain WHY
each level’s
TEMPERATURE
responded
as it did to the
Agung & Pinatubo
eruptions?
(by referring to the
Radiation Balance)
When ANSWERING # 3 & #4 – focus on
Agung & Pinatubo only
p 74
REMEMBER THIS IMPORTANT GRAPH?
Net radiation
deficit
Net radiation
surplus
Net radiation
deficit
What do the black & gray
areas represent?
(at top of atmosphere)
SKETCH A NEW CURVE A OR NEW CURVE B to
show how the energy balance would change if
a major volcanic eruption occurred .
p 74
SKETCH A NEW CURVE A OR NEW CURVE B to show
how the energy balance would change if a major
volcanic eruption occurred .
B
A
Curve A or Curve B
can move Up or Down
due to a radiative
forcing in SW or LW
CURVE A
CURVE B
is
Smaller Surplus
Larger
Deficit
A moves down
Larger
Deficit
If incoming energy
represented by Curve A is
reduced (A curve goes down)
Larger
Surplus
Smaller
Deficit
Smaller
Deficit
B moves down
If outgoing energy represented
by Curve B is reduced
(B curve goes down)
Larger
Surplus
Smaller
Deficit
Smaller
Deficit
A moves up
If incoming energy
represented by Curve A is
increased (A curve goes up)
SmallerSurplus
Larger
Deficit
B moves up
Larger
Deficit
If outgoing energy represented
by Curve B is increased
(B curve goes up)
Assume:
• that the eruption produces a long-lived
aerosol veil in the stratosphere over both
hemispheres
• that this veil reflects large amounts of
incoming solar radiation back to space
before it enters the troposphere’s earthatmosphere system shown in the graph.
•
Hint: you do not need to worry about stratospheric
warming for this question.
p 74
IF CURVE A
is affected:
If CURVE B
is affected:
Four scenario’s are possible for how you
should sketch the new graph
THE ANSWERS!
#1. List 4 reasons why Tambora in 1815
resulted in the largest GLOBAL cooling:
#1 Low latitude eruption  both hemispheres
#2 Large amount of eruptive material (50 sq km!)
#3 Aerosol cloud was HUGE and went into both
hemispheres equally
#4 Sulfuric acid (H2SO4) content was very large
p 74
#2. Give at least two reasons why
the eruption of Mt St. Helens was
NOT a very climatically effective
eruption:
#1 High latitude – could only affect part of
Northern Hemisphere
#2 Low sulfur content
(also, low volume, didn’t get to
S. Hemisphere, etc.)
p 74
# 3 HOW did the temperature at the 4 levels respond
to the Agung and Pinatubo eruptions?
#4 EXPLAIN WHY – referring to Radiation Balance?
Level A (Surface) – Cooled
Why?
by sulfate aerosols in stratosphere and
therefore less SW got into troposphere to be
absorbed by Earth’s surface
Level B (Lower Troposphere) – Cooled
Why?
by stratospheric aerosols => less SW
absorbed at surface and in troposphere,
ALSO: less
radiated up into troposphere from
the cooler Earth’s surface
p 74
Level C (Lower Stratosphere) – Warmed
immediately after both eruptions
Why? Sulfate aerosols in the stratosphere
absorbed some wavelengths of incoming SW
and heated up, they also absorbed some of the
Earth’s outgoing LW
as it radiated up out of
the troposphere
p 74
TO SUMMARIZE: 2 KEY POINTS
• Major eruptions with a long-lived sulfate
aerosol veil REFLECT incoming solar
radiation back to space BEFORE it enters
the mid- & lower troposphere or gets to the
Earth’s surface, hence the troposphere &
surface get COOLER after an eruption.
• The aerosols in the stratosphere can also
ABSORB some wavelengths of incoming SW
and outgoing LW, so that the stratosphere
WARMS slightly after an eruption.
Show how the energy balance would change
if a major volcanic eruption occurred:
WHICH ONE IS RIGHT ?
Does the change affect CURVE A or CURVE B?
A moves down, and B stays the same . . . .
. . . but eventually B will also move
down a bit due to cooler Earth temps
and less outgoing LW
p 74
ZOMBIE
BREAK !
MOVIE
TIME!!
TOPIC # 14
GLOBAL WARMING &
ANTHROPOGENIC
FORCING
TODAY’s 3 KEY CONCEPTS:
Carbon / Forests / Deforestation
 Computer Model Evidence for
Anthropogenic GW Forcing
 Tying it all together w/
RADIATIVE FORCING GRAPHS

TOPIC # 14
GLOBAL WARMING &
ANTHROPOGENIC
FORCING
Part A - CARBON RESERVOIRS &
FLUXES: Natural vs. Anthropogenically
Enhanced
(or How does all that “C” get into the atmosphere??)
Class Notes pp 75
“I'm extremely concerned that the Earth has
a chronic disease, and that chronic disease
is CO2 syndrome, it‘s something that's
creeping on us.
We have plenty of fossil fuel so it's going to
continue to get worse, and it's going to
affect every aspect of life on the planet,
from food production to drinking water to
coastlines to the plight of the poor in the
tropics, and so forth.”
~Wally Broecker , Paleoclimatologist
p 75
CO2 & CARBON
RESERVOIRS
CO2 in the atmosphere is one
place CARBON resides in the
Earth-Atmosphere system.
Where else is carbon located and
how does it move (flux) from one
reservoir to another?

Major
Reservoirs of
Carbon
at or near the
Earth’s surface
Gt (C) = gigaton carbon
p 75
Amount of carbon is expressed in units
of Gtons (gigatons) of carbon: GT(C)
Amounts represent the MASS OF
CARBON ATOMS ONLY, not other atoms
to which C is attached (e.g. CO2)
p 75
One gigaton is . . .
• 2740 Empire State Buildings or
77 Empire State Buildings made
out of solid lead
• 142,857,142 African elephants
-- That’s enough elephants
stacked on top of each other to
reach from Earth to the moon
and halfway back
• Greater than the mass of all
the humans on the planet

Major
Reservoirs of
Carbon
at or near the
Earth’s surface
Gt (C) = gigaton carbon
p 75
60
(Contributes
to GH effect)
0.06
62.5
1.5
6
0.5
90
92.5
Major
Carbon
Fluxes
IN & OUT
of the
atmosphere
In Gtons
p 75
Biomass = the total mass of organic
matter in living organisms in a particular
reservoir.
(Definition
on p 84)
The total amount
of carbon in
LIVING
BIOMASS = 610 Gt
The total amount of
carbon in the
ATMOSPHERIC
CARBON
RESERVOIR = 770 Gt
(760 Gt is in CO2 gas)
p 75
How does CARBON “flux” FROM the
biosphere INTO the atmosphere?
1. Trees take in carbon dioxide
during photosynthesis.
2. Trees release carbon dioxide
during photosynthesis.
3. Trees release carbon dioxide
into the atmosphere during
respiration.
NATURAL FLUXES INTO & OUT OF THE
ATMOSPHERIC CARBON RESERVOIR related
to BIOMASS = respiration & photosynthesis
FLUX from PLANT INTO ATMOSPHERE:
FLUX OUT OF ATMOSPHERE into PLANT:
p 76
The Atmospheric Carbon Reservoir
showing inflows and outflows (fluxes)
p 75
. . . leads to a
STEADY STATE
In the atmospheric
CO2 “reservoir”
Where have we a STEADY STATE before?

SOME DEFINITIONS:
Respiration =
biochemical process
living organisms take up O2,
consume organic matter,
RELEASE CO2, heat, & H2O
Decomposition =
breakdown of organic matter
by bacteria and fungi,
RELEASES CO2 to the atmosphere
p 76
Photosynthesis =
manufacture of carbohydrates & O2
from CO2 and H2O
in the presence of chlorophyll
sunlight as the energy source.
Oxygen is released in the process.
Solar energy chemical energy
(Part of chemical energy is stored in living tissues &
used by other organisms (consumers) that cannot use
solar energy directly.)
p 76
Photosynthesis
Respiration, Burning
of Biomass, &
Decomposition

WHAT ABOUT THOSE ZIG-ZAGS IN THE KEELING CURVE?
p 76
CLOSE-UP VIEW:
Trend due to anthropogenic increases
has been removed.
p 76
Oscillations represent seasonal fluctuations
driven by the balance between
respiration & photosynthesis
(dominated by Northern Hemisphere forests)
p 76
N.H.
S.H.
The largest forested areas are in
the Northern Hemisphere
GLOBAL VEGETATION PATTERNS

“Breathing” -- ANIMALS vs. PLANTS
Respiration
O2
CO2
Photosynthesis
CO2 O2
Respiration &
Decomposition
O2 CO2

Tick marks are at January
of each year:
JUL
JUL
Photosynthesis > Respiration
(CO2 goes down in SUMMER as
forests “breathe in” more CO2)
Respiration > Photosynthesis
(CO2 levels rise in FALL/WINTER as
forests “breathe out” more CO2)
Photosynthesis > Respiration
(CO2 goes down in summer)
Respiration > Photosynthesis
(CO2 levels rise in fall/winter)
JAN
JAN
p 76
350 ppm CO 2
review
BUT IS ALL THE EXTRA CO2
A BAD THING???
PLANTS DEPEND ON CO2!!!

Mini- Zombie Break:
YOU TUBE!
http://www.youtube.com/watch?v=0_VmMIbWKoo
With rising CO2 levels:
• Some plant species
continue to increase
photosynthesis (C3)
• others do NOT (C4)
•Some plants can
respond readily to higher
CO2 levels
• Other plants can
make only limited
responses
Hence with Increased CO2 :
• some plant species will be stronger, more prolific, and
may overwhelm those less able to benefit
WE ARE ALREADY SEEING POLLEN INCREASES
FROM RAGWEED & OTHER PLANTS
And . . . there may be consequences we don't yet know !!

Greater atmospheric CO2 concentration
 enhanced photosynthesis (due to “CO2 Fertilization”)
 more CO2 being assimilated by plant
from the atmosphere
 less atmospheric CO2
What kind of FEEDBACK LOOP?
-
Atmospheric
CO2
Negative &
self-regulating!
. . . but the jury is still out on how well this
negative feedback loop can counteract
HUGE anthropogenic influxes of CO2

LAND USE CHANGES:
Deforestation practices increase burning
& decomposition of large areas of forest

CARBON DIOXIDE: Trends
Data from ice cores
Review
Time Series Graph comparison of two
ways CARBON gets into atmosphere:
p 77
November 11, 2009
“Imagine if you took all the cars, trucks, planes, trains
and ships in the world and added up their exhaust
every year. The amount of carbon dioxide, or CO2, all
those cars, trucks, planes, trains and ships collectively
emit into the atmosphere is actually less than the
carbon emissions every year that result from the
chopping down and clearing of tropical forests in
places like Brazil, Indonesia and the Congo. “
“We are now losing a tropical forest the size of New
York State every year, and the carbon that releases into
the atmosphere now accounts for roughly 17 percent of
all global emissions contributing to climate change. “
http://www.nytimes.com/2009/11/11/opinion/11friedman.html

Much of increase in China due
to AFFORESTATION = planting new
forests in places where preceding
vegetation or land use
was not a forest
Highest
rates of
DEFORESTATION
in red
decrease
Figure on p 175
in Dire Predictions
increase
Data Source: UN / FAO Global Forest
Assessment Report
http://www.fao.org/forestry/fra/41555/en/
Forest carbon
emissions INTO the
atmosphere ( + )
- Forest uptake of
carbon OUT OF
the atmosphere ( - )
Since ~1950, USA & EUROPE have
become net carbon SINKS (rather
than sources) due to reforestation
from pp 174-175 in Dire Predictions
Palm oil
plantations!
p 77
Some good news? . . .
thtp://www.abc.net.au/news/stories/2009/11/13/2742229.htm

COME & GET YOUR EXAMS . . . .
HAVE A GREAT WEEKEND . . .
. . . but DON’T FORGET RQ-7!!
GO CATS . . .
. . . .ALL TEAMS!!
Some Quotes from the Newly Elected . . .
"With the possible exception of Tiger Woods, nothing has had a
worse year than global warming. We have discovered that a good
portion of the science used to justify "climate change" was a
hoax perpetrated by leftist ideologues with an agenda."
—Todd Young, new congressperson from Indiana
"I absolutely do not believe that the science of man-caused
climate change is proven. Not by any stretch of the imagination.
I think it’s far more likely that it’s just sunspot activity or
something just in the geologic eons of time where we have
changes in the climate.“
—Ron Johnson, new senator from Wisconsin
"I think we ought to take a look at whatever the group is that
measures all this, the IPCC, they don't even believe the crap.“
—Steve Pearce, new congressperson from New Mexico
"It's a bigger issue, we need to watch 'em. Not only because
it may or may not be true, but they're making up their facts to
fit their conclusions. They've already caught 'em doing this.“
—Rand Paul, new senator from Kentucky
"There isn't any real science to say we are altering the
climate path of the earth."
—Roy Blunt, new senator from Missouri
So, how do we begin to sort this
out – or do we even need to?
Is it just political “talking points”
OR
a serious science-based
disagreement characterized by
open-minded inquiry and healthy
skepticism?