Carbon Cycle

Pam Cohea

Newton’s First Law of Thermodynamics:

“Energy cannot be created or destroyed, it can only be transformed

from one form to another”

(1701)

How does Newton’s statement about energy relate to the Carbon Cycle?

Let’s discuss the diagram on the next slide.

Carbon is the basis for all orgainic compounds and a major element involved in the fixation of energy by photosynthesis. In fact carbon is so closely tied to energy flow that the two are inseparable.

Why is Photosynthesis important in the Carbon Cycle?

PHOTOSYNTHESIS is one of the most important biological process on earth!

• Provides the oxygen we breathe

• Consumes much of the CO2

• Produces food

• Supplies energy

Why is Respiration important in the Carbon Cycle?

• Process of making energy of food available in the cell…

• Involves breaking down• Complicated molecules into simple molecules

(C6H12O6, sugars) (CO2, water)

All organisms require energy • The way living organisms obtain

energy is through cell respiration

• Carbon dioxide is a product of respiration

We are now familiar with how the atmosphere and vegetation exchange carbon. Plants absorb CO2 from the atmosphere during photosynthesis, also called primary production, and release CO2 back in to the atmosphere during respiration. Another major exchange of CO2 occurs between the oceans and the atmosphere. The dissolved CO2 in the oceans is used by marine plants in photosynthesis.

• Two other important processes are fossil fuel burning and changing land use. In fossil fuel burning, coal, oil, natural gas, and gasoline are consumed by industry, power plants, and automobiles. Changing land use is a broad term which encompasses a host of essentially human activities. They include agriculture, deforestation, and reforestation.

Processes that release CO2 into the atmosphere are called carbon sources, while processes that absorb it are called carbon sinks. The amount of carbon in the atmosphere at any one time dependson the balance that exists between carbon sinks and carbon sources. Thissystem of sources and sinks operates all over the planet and is known asthe carbon cycle.

The two scenes below represent two major sinks of the carbon cycle

   

                                                                                          

                                                                                          

   Terrestrial Ecosystem                                           Marine Ecosystem  

Natural sources of atmospheric CO2 include volcanoes, fires, decomposition,respiration, digestion and, under certain conditions, oceans and fresh water bodies. The latter can release large amounts of dissolved CO2 when waters warm up or are disturbed by storms or tremors.

Natural sinks for atmospheric CO2 include photosynthesis, oceans and freshwater bodies, fossil fuels and carbonate rocks, and the short and long carbon cycles.

Intrusion into the Carbon Cycle

• The carbon cycle works as an input output system. The balance of this system is very important to maintaining the Global Carbon Cycle.

• Increased use of fossil fuels, burning forest, cutting down forest and other intrusions can cause an imbalance in the cycle.

Works Sited

• http://epa.gov/climatechange/kids/carbon_cycle_version2.html• http://en.wikipedia.org/wiki/Carbon_cycle• http://www.cotf.edu/ete/modules/carbon/efglossary.html#biogeoche

mical%20cycle• http://www.purchon.com/ecology/carbon.htm• http://www.hctf.ca/wild/educator/documents/tsink.pdf