Amy Weislogel & Aniketa ShindeWVU

Carbon & Climate

1GEOL 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. TrueB. 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!

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Dominant Greenhouse Gas:Carbon dioxide – CO2

A carbon atom bonds with 2 oxygen atoms to form 1 carbon dioxide molecule

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Today, CO2 makes up ___ of the total atmosphere.

A.<0.1 %B.1%C.10%D.50%

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:

At times… CO2 left the

atmosphere Where did it go?

CO2 came into the atmosphere Where did it come

from?

TODAY!

The Carbon Cycle

A cycle in which carbon moves between the biosphere, lithosphere, hydrosphere and atmosphere

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)

7 minut

es

Atmosphere

“Your Sphere”

Group Activity: List processes by which carbon/carbon dioxide moves to/from the atmosphere and your sphere

From atmosphere to “your sphere”:Idea 1Idea 2Idea 3Idea 4

From “your sphere” to atmosphere:Idea 1Idea 2Idea 3Idea 4

Blue = Hydrosphere (H)Pink= Lithosphere (L)Yellow = Biosphere (B)

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

Atmosphere

“Your Sphere”From atmosphere

to “your sphere”:Idea 1Idea 2Idea 3Idea 4

From “your sphere” to atmosphere:Idea 1Idea 2Idea 3Idea 4

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:

What processes What processes put COput CO22 IN to the IN to the atmosphere?atmosphere? Biosphere in (BIN) Hydrosphere in (HIN) Lithosphere in (LIN)

Process (draw) what we’ve learned:

What processes What processes take COtake CO22 OUT of OUT of the atmosphere?the atmosphere? Biosphere in (BIN) Hydrosphere in (HIN) Lithosphere in (LIN)

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.IncreaseB.DecreaseC.Stay the same

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

LIN + BIN + HIN < LOUT + BOUT + HOUT

shrinks

Carbon dioxide through time:

Geological evidence suggests CO2 levels change through time:

LIN + BIN + HIN ≠ LOUT + BOUT + HOUT

A. LIN + BIN + HIN = LOUT + BOUT + HOUT

B. LIN + BIN + HIN < LOUT + BOUT + HOUT

C. LIN + BIN + HIN > LOUT + BOUT + HOUT

Which equation describes the carbon budget from 375-300 Ma?

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 ppmB.390 ppmC.3900 ppmD.9750 ppm

ppm = parts per million

Humans are now taking carbon from the lithosphere, making CO2 and releasing it to the atmosphere…..

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

Feedback: a self-regulatory system, in which

the output affects the input, either positively or negatively Negative feedback opposes

expansion Positive feedback accelerates

expansion

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Chemical Reservoirs

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. Positive feedbackB. Neutralizing feedbackC. Negative feedbackD. 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

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Marine phytoplankton Preserved in

times of anoxia Store 12C Enrich oceans

in 13C

Carbon Isotopes

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Terrestrial plant ecosystems work the same way Preserved in

times of anoxia Store 12C Enrich

atmosphere in 13C

Carbon Isotopes

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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 occurring

Around 300 Ma, there was much more carbon-13 in the atmosphere than

carbon 12. Why?

A. Abundant plants grew in coal swamps

B. Many plants went extinct and so not many plants were growing

C. Coal seams were weathered or burned, releasing carbon 13 to the atmosphere

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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

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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.)

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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. δ13C will decreaseB. δ13C will increaseC. 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

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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 subduction48