The Carbon Cycle

An elementCarbon exists in the nonliving environment (POOLS) as:

- carbon dioxide (CO2) in the atmosphere and dissolved in water- the lithosphere: carbonate rocks- deposits of coal, petroleum, and natural gas derived from once-living things - dead organic matter, e.g., feces in the soil

Carbon exists EVERYWHERE!

What is carbon?

Carbon is exchanged between the active pools due to various processes. For example: Photosynthesis and respiration between the land and the atmosphere, and diffusion between the ocean and the atmosphere.

Quick Review of Photosynthesis

• How plants turn light energy into chemical energy.

• How plants make their own food

EQUATION FOR PHOTOSYNTHESIS

6CO2 + 6H2O +ENERGY C6H12O6 + 6O2

CARBON DIOXIDE

WATER

GLUCOSE

OXYGEN

Quick Review of RespirationRespiration is the opposite of

photosynthesis

Who? Plants AND AnimalsWhat? Sugar is broken down into carbon dioxide

and water

EQUATION FOR RESPIRATION

C6H12O6 +

GLUCOSE

6O2

OXYGEN

6CO2 +

CARBON DIOXIDE

6H2O +ENERGY

WATER

ATP

6 WAYS CARBON IS MOVED

IN A CYCLE

1.Carbon moves from the atmosphere to plants

In the atmosphere, carbon is attached to oxygen in a gas called CO2. With the help of the sun, CO2 is pulled from the air to make plant food from carbon through a process called photosynthesis

2. Carbon moves from plants to animals

Through food chains, the carbon that is in plants moves to the animals that eat them. Animals that eat other animals get the carbon from their food too.

3. Carbon moves from living things to the atmosphere.

Through RESPIRATION!Every time you exhale, you release

CO2 into the atmosphere. Animals and plants get rid of CO2 through respiration too!

4. 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 the carbon quickly enters the atmosphere as CO2.

5. Carbon moves from the atmosphere to the ocean

The oceans and other bodies of water soak up some carbon from the atmosphere.

6. Carbon moves from plants and animals to the ground

When plants and animals die, their bodies, wood and leaves decay bringing the carbon into the ground. Some become buried miles underground and will become fossil fuels in missions and millions of years.

7. Burning trees release carbon into the atmosphere

• Large forest fires can release lots of carbon dioxide (CO2) into the atmosphere.

8. Volcanic eruptions release carbon into the atmosphere

• Volcanic eruptions are not an everyday occurrence that most people experience. But volcanoes erupt, they can release large amounts of carbon dioxide into the atmosphere.

Carbon has been in balance for millions of years

But the last century CO2 levels have been increasing.

Why? Burning fossil fuels

The Greenhouse Effect!Think of the inside of a car in summer…• Sun passes through the car’s windows, but it

doesn’t pass back through very easilyTHIS IS WHY ITS SO HOT!

Greenhouse gasesact like glass in agreenhouse or a car

So…What can we do?

• Turn off lights• Carpool with friends• Recycle• Put on a sweatshirt (instead of pumping up your

heat in the winter)

….just to name a few…