• Carbon is an element
• It is part of oceans, air, rocks, soil and all living things.
• Carbon doesn’t stay in one place.
Carbon moves from the atmosphere to
plants.
Atmosphere-carbon is attached to oxygen in the form of
carbon dioxide (CO2).
CO2 with the help of the sun, using a processes called
photosynthesis, is pulled from the air to make plant food.
(C6H12O6)
Photosynthesis
6CO2 + 6H2O
Light Energy
C6H1206 + 12 02
Carbon moves from plants to animals
• Carbon that is in plants move to animals that eat the
plants.
• Animals that eat other animals get the carbon from the
plants the other animals have eaten
Carbon moves from living things to the
atmosphere
• Exhaling releases CO2 into the atmosphere.
• Animals and plants get rid of CO2 gas through a process
called respiration.
Carbon moves from plants and animals to the
ground
• When plants and animals die, their bodies, wood and
leaves decay bringing carbon into the ground.
• Some becomes buried miles underground and will
become fossil fuels in millions and millions of years.
Carbon moves from plants and animals to the
ground continued
Carbon moves from fossil fuels to the
atmosphere when fuels are burned.
• When humans burn fossil fuels to power factories, power
plants, cars and trucks, most of the carbon quickly enters
the atmosphere as CO2
• Yearly five and a half BILLION tons of carbon is release by
burning fossil fuels (or the weight of 100 MILLION adult
elephants)
• 3.3 billion tons enter the atmosphere and the rest
becomes dissolved in seawater
Carbon moves from the atmosphere to the
oceans
• Oceans and other bodies of water, soak up some carbon
from the atmosphere.
• Animals that live in the ocean use carbon to build their
skeletons and shells
coccolith
White Cliffs of Dover, England
Carbon dioxide is a green house gas
• CO2 traps heat in the atmosphere
• Without CO2 and other greenhouse gases, Earth would be
a frozen world
• Humans have burned so much fuel that there is about
30% more CO2 in the air today than there was about 150
years ago.
• More greenhouse gasses such as CO2 in our atmosphere
are causing our planet to become warmer.
Carbon moves through our planet over longer
time scales
• Over millions of years weathering of rocks on land may
add carbon to surface water which eventually runs off to
the ocean.
• Carbon is removed from seawater when the shells and
bones of marine animals and plankton collect on the sea
floor. Shells and bones are made of limestone, which
contains carbon.
• When the shells and bones are stored on the sea floor
they are removed from the carbon cycle
Carbon moves through our planet over
longer time scales continued
• Carbon can be released back to the atmosphere if the
limestone melts or is metamorphosed in a subduction
zone.
Movement of carbon
Feedback Systems
• Negative Feedback
The case where the output of a system counteracts
the input of the system.
Body temp
Sweating
Feedback Systems
• Positive Feedback
The case where the output of a system increases the
input of the system
Bank account
balance
Interest
earned
Carbon Cycle Feedback
• The carbon cycle is naturally a negative
feedback loop.
• The burning of fossil fuels and deforestation
interferes with this feedback loop.
Deforestation increases atmospheric CO2.
Burning of fossil fuels also increase atmospheric
CO2.