In the natural carbon cycle, there are two main processes which occur:
photosynthesis and
metabolism.
During photosynthesis, plants usecarbon dioxide
and produceoxygen.
During metabolism oxygen is used and
carbon dioxide is a product.
Humans impact the carbon cycle during the combustion
of any type of fossil fuel, which may include oil, coal, or natural gas.
Fossil Fuels were formed very long ago from plant or animal remains that
were buried, compressed, and transformed into oil, coal, or natural gas.
The carbon is said to be "fixed" in place and is essentially
locked out of the natural carbon cycle. Humans intervene during by burning
the fossil fuels. During combustion in the presence of air (oxygen), carbon
dioxide and water molecules are released into the atmosphere.
The question becomes as to what happens to this extra carbon dioxide
that is released into the atmosphere. This is the subject of considerable
debate and about it possible effect in enhancing the greenhouse effect
which may than result in global warming.
