G8_The Story of Coal and the Carbon Cycle_Approaching_03
He explained that plants take in carbon dioxide and release oxygen. A large, dense forest would be taking in a lot of carbon as the trees grow. This action is just one of the many critical parts in the carbon cycle. It is this process that moves carbon from the atmosphere to the biosphere.
Typically, when vegetation dies, the decay process begins almost immediately. This decay process breaks down the plant matter into simpler organic matter. This process releases the locked-up carbon. This process is called decomposition. In these low-lying swampy areas, the water is still and contains very little oxygen. This stagnant water thereby slows the decay process of the plant matter that falls into the water. Over time, sedimentation covers the dead plant matter that has fallen into the shallow waters. As more and more sediments were deposited over the plant matter, the plant matter is compressed.
This action provides more protection from natural decay. In a coal forest, this process of decay is bypassed. This bypassing enables the carbon content of the plant matter to stay intact. In this case, for over 300 million years. Without this unique environment, the carbon would have been quickly return to the atmosphere.
The guide further explained of how coal is formed from the plant matter. He discussed how, as time passed, the organic sediment was covered with more and more soil, getting buried deep under the layers of sediment. Once the temperature and pressure reached a high enough level, the “coalification process” begins.
Coalification is a chemical process. In simple terms, it involves the pushing out of water, methane, and carbon dioxide. This chemical process leaves behind a rich concentration of carbon. Coals is ranked according to the amount of carbon it contains.