THE GLOBAL CARBON
CYCLE
THE GLOBAL CARBON CYCLE
Movement of carbon atoms within Earth’s
ecosystems KEEPS CARBON AND OUR
ENVIRONMENT IN EQUILIBRIUM
THE GLOBAL CARBON CYCLE
Movement of carbon atoms within Earth’s ecosystems.
Carbon RESERVOIRS (biomass, oceans, soil, carbonates, atmosphere &
fossil fuels)
Carbon PROCESSES (photosynthesis, cellular respiration, combustion,
decay, sedimentation, compaction and dissolving)
THE GLOBAL CARBON CYCLE: MOVEMENT
Energy Input:
Energy Output:
All movements either require or release energy.
PHOTOSYNTHESIS – requires energy from the SUN.
RESPIRATION (or COMBUSTION) – releases energy for
USE.
THE GLOBAL CARBON CYCLE:
RESERVOIRS
THE GLOBAL CARBON CYCLE: DISRUPTION
HOW DO WE DISTURB (DISRUPT) THE CARBON CYCLE?
(Take carbon out of the cycle or put too much back in)
Human activities that disrupt the Carbon cycle:
Making concrete
burning fossil fuels
Example:
clearing forests
manmade products
making plastics removes Carbon from the cycle
& BURNING FOSSIL FUELS (combustion) ADDS EXCESS.
RECYCLING

How does recycling help the carbon cycle?

How did carbon dioxide increase so much?
THE GLOBAL CARBON CYCLE
COMBUSTION – the chemical reaction
between hydrocarbons and oxygen
=> puts Carbon back into the cycle
THE GLOBAL CARBON CYCLE
coal: C + O2  CO2
 Burning natural gas:
CH4 + 2O2  CO2 + 2H2O
 Burning gasoline:
2C8H18 + 25O2  16CO2 + 18H20
 Burning
Incomplete combustion creates CO (Carbon
monoxide) instead of CO2
THE GLOBAL CARBON CYCLE
 What
are the 2 things REQUIRED for
COMBUSTION?
A
 What
hydrocarbon AND oxygen
happens when there is not enough
OXYGEN?
 Carbon
monoxide (CO) is produced (and
not all the fuel is used up)