The Carbon Cycle

The Carbon Cycle
The Carbon Cycle
Earth-Space Science
The Geosphere Lesson 02
By the end of this lesson you should
be able to:
• Discuss the steps of the carbon cycle
• Analyze movement of matter and energy
through the carbon cycle
• Discuss interactions of the carbon cycle with
all spheres of Earth (hydrosphere,
cryosphere, geosphere, biosphere &
Carbon and Carbon Dioxide
• Carbon – the 6th most abundant
element in the universe.
– Some examples: Coal, Graphite,
• Carbon Dioxide
– Two (di) oxygen atoms bonded to one
Carbon – often written as CO2
– A trace gas, crucial in photosynthesis
when plants take in CO2 and release O2
6 CO2 + 6 H2O → C6H12O6 + 6 O2
Carbon dioxide + Water + Light energy →
Glucose + Oxygen
How does the carbon cycle impact
Earth's spheres?
Biosphere –
Includes all
living things on
Earth, such as
plants and
Hydrosphere – All of
the water in the
Earth’s oceans
lakes, rivers and
Exosphere- Everything
located outside of the
Earth, including stars
and galaxies.
– The thin
layer of gas
the Earth
Geosphere –
The land
surfaces and
interior of
the Earth.
Cryosphere – All of the
ice on Earth such as
glaciers and the icecaps.
Earth Cycles
• Essential element: A chemical element from the periodic
table that is necessary for life processes on Earth
• Biogeochemical cycles: The essential elements move
through cycles in the Earth system, taken up by living
organisms (Biosphere) and then returning to one of the
Earth’s spheres after the organisms die, and eventually are
taken up by living organisms.
• Conservation of Matter Review – Matter cannot be created
or destroyed (from BWS)
• The Carbon Cycle : The carbon cycle is the movement of
carbon between the biosphere and the other nonliving
spheres of Earth. Smaller cycles exist within the main
Carbon Cycle. And we will look at those now…
Carbon Dioxide CO2
Where is it?
+ CO2 is
released by
and people
fossil fuels
+ CO2 is held
in the
as a trace
+ CO2 is
exhaled by
+ Trees use CO2 to make food
and give off oxygen.
Deforestation leads to higher
CO2 levels.
+ Dead and
plants and
release CO2
+ CO2 is
held in
water as a
Photosynthesis &
Short Term Carbon Cycle
A product of the carbon cycle is oxygen, when the
process of photosynthesis takes carbon from
the atmosphere and stores it in the plant as
sugar that can be used as a source of energy.
Oxygen released from plants is then exchanged in
the lungs of animals during the process of
One of the products of the process of respiration is
carbon dioxide (CO2), which is released back
into the atmosphere.
Animals release the carbon in the food molecules
back to the geosphere through the process of
excretion. Plants and animals also release
stored carbon through the process of
Carbon is released by other organisms, known as
decomposers, which break down waste
material. The carbon becomes a part of the
geosphere or hydrosphere once again.
What are Fossil Fuels?
• Living creatures on Earth are Carbon based
• Dead organisms (mostly plants) become
buried, metamorphose (heat and pressure)
• Burning of fossil fuels releases the trapped
• Considered Non-Renewable because it takes
millions of years for the metamorphism to
occur – Used much faster than produced
Long Term Carbon Cycle
A Geologic Process
• Carbon is stored in rocks, soils, and fossil fuels,
and is also released through volcanic eruptions
• Fossil Fuels include – Coal, Oil, and Natural Gas
and can be burned for energy, releasing CO2
• Combustion (burning) of plant matter (leaves
etc) also releases CO2 to the atmosphere
• Deforestation removes plants therefore they
can no longer remove CO2 from the atmosphere
Long Term Carbon Cycle
• Can you smell your perfume as well at the end of
the day as you can at the start?
• Diffusion – substances move from high
concentration to low concentration
• Gaseous CO2 is dissolved in the ocean in large
amounts and will diffuse to the atmosphere
• Rain can pick up CO2 from the atmosphere
producing acid rain
• Takes CO2 back to the Earth, and hydrosphere
Long Term Carbon Cycle
Biosphere & Geosphere
• Some sea animals take CO2 from ocean water and
secrete shells
• When the animals die, their shells fossilize,
eventually break down, or weather/erode and
release Carbon
• Shells, and excrement will all fall to the bottom of
the water, leading to a higher Carbon content in
deep water.
• Ocean currents circulate water and brings carbon
to the surface
• Note that
the blue
• Other
What can YOU do?
Carbon footprint: "the total set of greenhouse
gas (GHG) emissions caused by an
organization, event, product or person.".
There would be very little point in my exhausting myself
and other conservationist themselves in trying to protect
animals and habitats if we weren't at the same time
raising young people to be better stewards.
- Dr. Jane Goodall Primatologist, ethologist and anthropologist
Mrs. Renee Mitchell
Earth-Space Science Instructor
[email protected]

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