Carbon & Climate
Amy Weislogel & Aniketa Shinde
WVU
1
GEOL
103: Earth Through Time, ~360 students
Learning Goals & Outcomes

Goals:


Understand how earth’s climate has warmed and cooled over time
due to natural processes and process by which human activities are
impacting the climate system
Outcomes:






Discriminate between climate and weather
Predict climate response to changes in CO2 greenhouse gas
concentrations in the atmosphere
Know CO2 as a greenhouse gas
Model the carbon cycle
Carbon budget and impact of perturbations on the carbon cycle
Identify ways in which humans can affect change in the concentration
of CO2 in the atmosphere
Hook 1:
The average air temperature of Earth is
the same as the average air temperature
of the Moon.
A.
B.
True
False
Why?
Greenhouse gases

Atmospheric gases that trap warming solar
radiation near Earth’s surface

Without these gases the average temperature on Earth
would be 0° F Brrrr!
4
Dominant Greenhouse Gas:
Carbon dioxide – CO2

A carbon atom bonds
with 2 oxygen atoms
to form 1 carbon
dioxide molecule
Today, CO2 makes up ___ of the total atmosphere.
A. <0.1 %
B. 1%
C. 10%
D. 50%
5

Hook 2: CO2 in the atmosphere has
changed through time…
 Over the last ~650,000
years…

Analysis of air bubbles
trapped in ice sheets
UPSHOT:
TODAY!
At times…
 CO2 left the
atmosphere


Where did it go?
CO2 came into the
atmosphere

Where did it come from?
The Carbon Cycle

A cycle in which
carbon moves
between the
biosphere, lithosphere,
hydrosphere and
atmosphere
Lithosphere
How does
this happen?
Atmosphere
Hydrosphere
Biosphere
Group Activity
 You will receive 2 index cards
 Your group is assigned one of the following
“spheres” based on the color of your cards:



Hydrosphere (blue)
Lithosphere (pink)
Biosphere (yellow)
Group Activity: List processes by which
carbon/carbon dioxide moves to/from
the atmosphere and your sphere
From atmosphere
to “your sphere”:
Idea 1
Idea 2
Idea 3
Idea 4
“Your
Sphere”
Atmosphere
Blue = Hydrosphere (H)
Pink= Lithosphere (L)
Yellow = Biosphere (B)
From “your sphere”
to atmosphere:
Idea 1
Idea 2
Idea 3
Idea 4
Launching thought:
Carbon atoms occupy space in:
 *Atmosphere (where it causes warming of Earth’s surface)

CO2 (gas)
Hydrosphere
 What forms?
 Lithosphere
 What forms?
 Biosphere
 What forms?

HOW COULD CARBON MOVE TO/FROM THE ATMOSPHERE?
Jog your memory of the reading:
Listen carefully---
Hand one copy of your list to another group
working on the same sphere (same color)
and find another groups “extra” list to
compare your ideas with theirs…



Don’t alter the other group’s list, but…
Add ideas to your list that you think are good
Detract ideas from your list that you have
reconsidered
Jog your memory of the reading:
SWITCH AGAIN!
Jog your memory of the reading:
Time is up! I’ll select a few groups to send a member to
draw their group’s model on the appropriate white board
From atmosphere
to “your sphere”:
Idea 1
Idea 2
Idea 3
Idea 4
“Your
Sphere”
From “your sphere”
to atmosphere:
Idea 1
Idea 2
Idea 3
Idea 4
Atmosphere


If another group wrote an idea you had, put a star next to it
If another group wrote an idea that you don’t agree with, put an X next
to it
Process (draw) what we’ve learned:
Lithosphere
What processes
put CO2 IN to the
atmosphere?



Biosphere in (BIN)
Hydrosphere in (HIN)
Lithosphere in (LIN)
Atmosphere
Hydrosphere
Biosphere
Process (draw) what we’ve learned:
Lithosphere
What processes
take CO2 OUT of
the atmosphere?



Biosphere in (BIN)
Hydrosphere in (HIN)
Lithosphere in (LIN)
Atmosphere
Hydrosphere
Biosphere
If the amount of carbon transferred from the
lithosphere, hydrosphere and biosphere to the
atmosphere equals (is the same as) the amount of
carbon transferred to the lithosphere, hydrosphere
and biosphere from the atmosphere, then the
amount of CO2 in the atmosphere will:
A. Increase
B. Decrease
C. Stay the same

CO2 IN
(from
Lithosphere,
Hydrosphere,
Biosphere)
CO2 OUT
(to
Lithosphere,
Hydrosphere,
Biosphere)
THEN
Amount of
Atmospheric
CO2
Carbon Budget



Over short time scales, Carbon is neither created nor
destroyed (in significant amounts)
Carbon moves through a system at a rate in and a rate out
If rates are equal, then no change to the reservoir
LIN + BIN + HIN = LOUT + BOUT + HOUT
Carbon Budget

If rate IN is faster than rate OUT, amount of carbon dioxide
in the atmosphere increases
LIN + BIN + HIN > LOUT + BOUT + HOUT
Carbon Budget

If rate OUT is faster than rate IN, amount of carbon dioxide
in the atmosphere decreases
shrinks
LIN + BIN + HIN < LOUT + BOUT + HOUT
Carbon dioxide through time:

Geological
evidence
suggests CO2
levels change
through time:
LIN + BIN + HIN ≠ LOUT + BOUT + HOUT

Which
equation
describes the
carbon
budget from
375-300 Ma?
A. LIN + BIN + HIN = LOUT + BOUT + HOUT
B. LIN + BIN + HIN < LOUT + BOUT + HOUT
C. LIN + BIN + HIN > LOUT + BOUT + HOUT
Think-Pair-Share

What could
could have
caused the
sharp
decrease in
CO2 from
375-300 Ma?
LIN + BIN + HIN < LOUT + BOUT + HOUT
Carbon dioxide through time:
 What would be the concentration of CO2 in the
atmosphere ~550 Ma if today’s CO2
concentration is 390 ppm?
A. ~16 ppm
B. 390 ppm
C. 3900 ppm
D. 9750 ppm
ppm = parts per million
Humans are now taking
carbon from the
lithosphere, making CO2
and releasing it to the
atmosphere…..
Hydrosphere
Lithosphere
Atmosphere
Anthropogenic
Biosphere
More carbon through human activities:
Anthropogenic (AIN)
Hook

Should CO2 be regulated as a pollutant?



What do you know?
What do you need to know?
Is anthropogenic input of CO2 into the atmosphere
causing global warming?


If so then regulation may be good
Is anthropogenic input of CO2 having no effect on
global temperature?

If so then regulation a waste of time and energy
The total mass of atmospheric carbon dioxide
is 3.16×1015 kg (about 3,000 gigatonnes)
 Humans are adding approximately 9
gigatons/year




3 is used up by photosynthesis
2 is absorbed by the ocean
4 gigatons/year remain
Carbon dioxide through time:

Geological
evidence
suggests CO2
levels up to
25x higher
than today
existed in the
past
Chemical Reservoirs
Feedback:
 a self-regulatory system, in which the
output affects the input, either positively
or negatively


Negative feedback opposes expansion
Positive feedback accelerates expansion
37
CO2 added to the atmosphere due to
burning fossil fuels causes warmer
temperature. These warmer
temperatures increase plant growth
across the planet; to grow, plants take
carbon from the atmosphere. This is an
example of a:
A.
B.
C.
D.
Positive feedback
Neutralizing feedback
Negative feedback
Isotopic shift
Global Climate Change

Paleoclimates – Past climates are indicated by
Earth materials that are climate-sensitive.

Geologic records: Sequences of strata

Depositional environments are often climate-sensitive.
Coral reefs – Tropical marine.
 Glacial tills – Cold and continental.

Carbon Isotopes

Marine
phytoplankton



Preserved in times
of anoxia
Store 12C
Enrich oceans in
13C
40
Carbon Isotopes

Terrestrial plant
ecosystems work
the same way



Preserved in times
of anoxia
Store 12C
Enrich
atmosphere in
13C41
Carbon Isotopes
Isotopic excursion — A
positive or negative shift in
an isotopic ratio through a
succession of stratigraphic
layers.
 Sample limestone and
measure stable C isotopes



Preserved in times of anoxia
Enrich oceans in 13C, growth
and burial of phytoplankton
42
occurring
Around 300 Ma, there was much more
carbon-13 in the atmosphere than
carbon 12. Why?
A.
B.
C.
Abundant plants
grew in coal
swamps
Many plants went
extinct and so not
many plants were
growing
Coal seams were
weathered or
burned, releasing
carbon 13 to the
atmosphere
43
Carbon Isotopes
Isotopes in
limestone (CaCO3)
 Phanerozoic record
indicates intervals
of great change


Late Carboniferous
swamps buried lots
of carbon

Excess 13C in
atmosphere and
oceans
44
Frozen Methane

CH4



Most produced by
prokaryotes
 Herbivore flatulence
Significant warming
Stored frozen on sea
floor and deep under
tundra


Low temperature, high
pressure formation
Also found on
continental slope (400–
1000 m w.d.)
45
Carbon in methane produced by bacteria
will be rich in carbon12. δ13C is the ratio
of 13C/12C. Big numbers mean more
13C, small numbers mean more 12C.
If abundant frozen methane melts and is
released to the atmosphere, how with the
δ13C value of the atmosphere change?
A.
B.
C.
δ13C will decrease
δ13C will increase
δ13C will stay the same
Frozen Methane

Release of frozen methane
releases carbon



Water at depth warms
Rapid release of greenhouse gases
(methane)
Positive feedback
 Continue to warm
 Signal is 12C dominated
47
Carbon
Isotopes

Weathering of
CaCO3 releases
Ca++ and HCO3



Carried to oceans
Precipitate limestone
skeletal material
Carbon is stored for
long time period
Released upon
subduction
48