IntroThere are many natural processes that are constantly happening around us, these processes are often linked by passing one type of atom to the next process which passes the same atom to the next and so on. This 'passage of the atom' along a chain of processes is called a cycle, the series of processes through which the carbon atom passes is called the carbon cycle. Each carbon is the fourth richest element in the universe and is an important part of most of the molecules that make up the majority of the world's natural resources and organic matter, which is why the carbon cycle is one of the most important cycles on earth. Earth. Throughout the cycle, carbon can take different forms such as sugar, oil, diamond and marble. Processes such as photosynthesis, combustion and land compression play a key role in changing, containing and releasing carbon. All chemical reactions, processes and forms created by carbon are part of the carbon cycle, which is one of the most important cycles on earth. Most of the carbon on earth is found in the atmosphere, the rest is stored in rocks, fossil fuels, oceans, plants and soil. Carbon is constantly being added to the atmosphere, the most common forms being carbon dioxide and methane gas. At the same time it is removed from plants on land and in the oceans. Carbon can be stored for hundreds of years in sediments, fossil fuels, rocks and the ocean. Carbon in the atmosphere is almost always a compound called carbon dioxide. Adding Carbon to the Atmosphere Currently, Earth's atmosphere contains most of the world's carbon; in 2010 carbon levels in the atmosphere were measured at 18.4 billion tonnes. Respiration and excretion The most common natural wa...... half of paper ......d used in photosynthesis. Carbon dioxide can also mix with water to create carbonic acid. Carbon dioxide (CO2) + water (H2O) = carbonic acid (H2CO3) which turns into carbon compounds that sink to the seabed, often these carbon compounds. Carbon is also consumed by aquatic plants and used in photosynthesis which is similar to the process in non-aquatic plants but there is an abundance of water and a limited amount of carbon atoms. Length of phases Carbon can remain in one phase of the cycle for an hour and in others up to 200 million years, depending on the phase of the cycle. Carbon, in the form of coal, oil and even diamonds, can remain underground for a million to 200 million years, longer than any other phase of the cycle. While carbon is consumed by plants for photosynthesis, carbon can be released within a matter of hours.