The Carbon Cycle
Hannah Evans
Karen Sloan
Andrea Renegar
Kelsey Peckham
Definition of Carbon Cycle:
the series of processes by which carbon
compounds are interconverted in the
environment, involving the incorporation of
carbon dioxide into living tissue by
photosynthesis and its return to the
atmosphere through respiration, the decay
of dead organisms and the burning of fossil
fuels
Why is there a carbon cycle?
● All living things are made of carbon!
● Carbon is always moving, which is why it
is called the Carbon Cycle.
Steps of the
Carbon Cycle
Step 1 : Carbon moves from
the atmosphere to plants.
- In the atmosphere, carbon attaches to
oxygen in carbon dioxide (CO2)
- Through photosynthesis, CO2 is pulled
from the air to make food for plants
from carbon.
Step 2: Carbon moves from plants to
animals.
- Through food chains, carbon moves
from plants to the animals that eat
them.
- Animals that eat animals also receive
carbon through this.
Step 3: Carbon moves from
plants and animals to the ground
- After the death of plants and animals,
they start decaying.
- The carbon dioxide from their bodies
then seeps back into the earth.
- Some of it will go miles deep in the earth,
stay there for millions of years, and turn
into fossil fuels.
Step 4 : Carbon moves from living
things to the atmosphere.
- When you exhale, you breathe out CO2
into the atmosphere.
- Through a process called respiration,
plants and animals get rid of CO2
Step 5: Carbon moves from fossil fuels
to the atmosphere when fuels are burned.
- When humans burn fossil fuels, the carbon
enters the atmosphere as carbon dioxide
gas.
- Each year, 5.5 billion tons of carbon is
released by burning fossil fuels.
Step 6: Carbon moves from the
atmosphere to the oceans
- The bodies of water on earth,
especially the oceans, absorb some of
the carbon from the atmosphere.
Effects of Carbon Dioxide:
-
Carbon dioxide is a greenhouse gas.
It traps heat in the atmosphere.
Without CO2, the Earth would freeze.
Yet, humans burn more and more fuel so
there is 30% more carbon dioxide in
the air than there was 150 years ago.
Earth is becoming a warmer planet.
This graph shows the increase in CO2
from the year 1900 - 2000
Sample Questions:
If the carbon dioxide in the atmosphere increases due to
human activities, what do scientists predict will be the
result?
A. increased cases of sunburn
B. warmer temperatures
C. increased incidence of earthquakes
D. more snowfall in the winter
Answer: B
Due to the increase of carbon dioxide gas
being released into the atmosphere,
temperatures are getting proceedingly
warmer.
For millions of years the carbon cycle has been in balance.
Climatologists are concerned because data indicates the
amount of carbon in the air is increasing. Which theory
best explains this loss of atmospheric balance?
A. CFAs have created a hole in the ozone.
B. Society has increased the burning of fossil fuels.
C. Environmentalists have increased the size of rain
forests.
D. Our society has recognized the danger of nuclear
fission.
Answer: B
The more fossil fuels that are burned, the
warmer temperatures get, therefore less
atmospheric balance.
Where do animals get the carbon found in their bodies?
A. from the air
B. from eating food
C. from the soil
D. from vitamins and minerals
Answer: B
Animals receive carbon through food chains.
Animals eat plants and receive carbon, and
animals that eat animals also receive
carbon.
Questions?
Resource Sites
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http://www.windows2universe.org/earth/Water/co2_cycle.html
http://www.esrl.noaa.gov/research/themes/carbon/
https://eo.ucar.edu/kids/green/cycles6.htm