Thursday, May 14, 2009

The Carbon Cycle



Now that we have learned about each of the major ecosystems of the world, lets learn more about the one major element that makes up the ecosystems: carbon. Carbon, a chemical element, can be found everywhere, all over the Earth. To begin things, carbon can be found all over the atmosphere in the carbon dioxide that makes up the atmosphere. Carbon is also stored in fossil fuels, along with certain types of rocks, shells, and animals. Carbon is also part of the dissolved soil found in the surface of the ocean, the bottom of the ocean, and underground. Finally, carbon is stored in plants and trees. Although carbon is stored in most objects, more complexity arrives when studying where carbon moves. One area to look where carbon moves would be a city, along with a lake, and a forest. In forests, trees and plants absorb carbon dioxide during the process of photosynthesis, and store carbon as they grow. When plants release some of this carbon into the atmosphere, this is called respiration. After the plants and trees die, they fall to the ground and decompose into material that makes up fossil fuels. Being that fossil fuels are made up of carbon, this is another example of how carbon moves in all sorts of directions. Hence, we can conclude that carbon is everywhere and moves in all sorts of directions. Although this may occur with plants and trees on land, the same cannot be said for the carbon cycle in water. Through a process called diffusion, gases that contain carbon move in between the atmosphere and the surface of the ocean. The one point that does not change between the carbon cycle on land and the carbon cycle on water, is that plants, both on land and water, use carbon dioxide in the process of photosynthesis. When primary consumers eat the plants that stored carbon through photosynthesis, the carbon gets passed on to the primary consumer. These animals and plants, then release carbon dioxide back into the water through respiration. When these plants and animals die, similar to the scenario on land, they fall to the bottom of the ocean and decompose. This compost can develop into fossil fuels, such as coal or natural gas, that is made up of carbon. Some sea creatures have the ability to remove carbon from the ocean and use it to make their shells. When these animals die, they settle at the bottom of the ocean. Although it takes a very long time for rocks to form and wear down, this process moves carbon in water. As for the city, it depicts how humans affect the carbon cycle by our daily activities.




Carbon Sources and Carbon Sinks

Carbon sinks are living things or objects that take in carbon. The difference between carbon sinks and carbon sources is that carbon sinks take in carbon and carbon source release or store carbon. A few examples of carbon sinks are redwood trees, landfills, and the ocean.
Carbon sources are living things or objects that contain and give off carbon. Carbon sources can be identified by the actions of the living things or the objects. For example, a carbon source is people breathing, driving a car, factory gases, or burning fossil fuels. When carbon is released, scientists call the objects or living things release agents.

Tuesday, May 12, 2009

Release Agents and their Harmful Effects

Release agents are living things or objects that release carbon into the air. Release agents are similar to carbon sources in the fact that they both store and release carbon. A few examples of release agents are volcanoes, forest fires, and humans. With all of these release agents and many more, some harm the environment.
Humans greatly influence the carbon cycle through many activities. For example, when we extract fossil fuels and burn them for energy, this is called combustion. Another example would include deforestation. Deforestation occurs when we cut or burn down trees, which allows carbon dioxide to move throughout the air and settle in the atmosphere. Since carbon dioxide is a greenhouse gas, this would contribute to global warming, making these two carbon sources harmful.