The Carbon Cyclex


22 févr. 2014 (il y a 3 années et 3 mois)

131 vue(s)

The carbon cycle is based on Carbon Dioxide (CO2 ),
the gaseous form in air, and dissolved form in water,
calcium carbonate.

Has 4 main pathways.


Mixed Geochemical Processes

Multiple Human Activities


Only some plants and bacteria can perform this process though
because they possess chlorophyll, a pigment molecule in leaves
that allow them to capture solar energy .

In this process, plants, and other producers, take in carbon
dioxide and water and turn them into complex carbohydrates,
such as glucose, under the influence of sunlight.

Once photosynthesis is complete, oxygen is
produced. We, humans, take in the produced
oxygen, and exhale it as Carbon Dioxide. This
creates a never ending cycle.

The decomposition of animals, plants, and other living things
release carbon dioxide into the air.

Some of these organisms are buried deep within the crust, and
will eventually, millions of years later, turn Into a fossil fuel.

Decomposition is the largest source through which carbon is
returned to the atmosphere as carbon dioxide.

Several things humans do produce carbon dioxide.

Each time you exhale, you are releasing carbon dioxide(CO
) into the

Mining, burning forests, and burning fossil fuels are some of the most
common ways humans release C0

When humans burn fossil fuels to power factories, power plants, cars and
trucks, most of the carbon quickly enters the atmosphere as carbon
dioxide gas.

During the burning in the presence of air (oxygen), carbon dioxide and
water molecules are released into the atmosphere.

Carbon dioxide is slightly soluble and is absorbed into bodies of
water such as the ocean and lakes.

It is not overly soluble as you see what happens when a can of
soda such as Coke is opened.

The warmer the water the less carbon dioxide remains in the

Some carbon dioxide is used by algae and other marine life
through photosynthesis, which creates oxygen and is then
released back into the atmosphere.

In other aquatic areas, some organisms such as coral and those
with shells take up carbon dioxide from the water and convert it
into calcium carbonate.

Carbonate sediments are constantly being formed and re
dissolved in the depths of the oceans.

Over periods of time, sediments may rise up as dry land or into
mountains which creates the sedimentary rock limestone. The
carbonates can re
dissolve releasing carbon dioxide back to the
air or water.

Each year, five and a half billion tons of carbon is released by
burning fossil fuels. That’s the weight of 100 million adult
African elephants!

Carbon dioxide is a greenhouse gas that traps heat in the
atmosphere. Without it, and other greenhouse gases, the Earth
would be frozen.

Of the huge amount of carbon that is released from fuels, 3.3
billion tons enters the atmosphere and most of the rest becomes
dissolved in