The Carbon Cycle is one of the most important natural processes that regulates the amount of carbon dioxide in Earth's atmosphere, thereby impacting climate change. This article will discuss an overview of the Carbon Cycle, its major processes, and the impact of human activity on it.
The carbon cycle, simply put, is the process by which the Earth's environment exchanges and stores carbon molecules. The most basic explanation of the cycle is that it is the exchange of carbon in various forms between the atmosphere, biosphere, hydrosphere, and geosphere. Carbon moves among these reservoirs as part of a series of chemical, physical, and biological processes.
Atmospheric carbon includes carbon dioxide (CO2) and methane (CH4). This carbon originates from both natural sources like respiration, and human-made sources like fossil fuel combustion. In the atmosphere, carbon dioxide can be taken up by plants during photosynthesis and converted into carbohydrates, releasing oxygen back into the atmosphere. Carbon is also released from the burning of fossil fuels, which releases CO2 to the atmosphere.
Carbon can accumulate in the biosphere in plants and animals in the form of organic material such as carbohydrates, proteins, lipids, and other organic compounds. In the hydrosphere, carbon is stored in oceans, lakes and rivers as dissolved organic carbon and inorganic carbonates. Finally, in the geosphere, carbon is stored in rocks and fossil fuels. Over long periods of time, rocks form through the accumulation of organic material and minerals, eventually creating layers of sedimentary rock, which are an important store of carbon.
In summary, the carbon cycle is a complex system of exchanges between the Earth’s four major reservoirs, and those exchanges have an important effect on the Earth’s climate. Carbon moves between places in the atmosphere, biosphere, hydrosphere, and geosphere as part of a complex network of chemical, physical, and biological processes.
The major processes in the Carbon Cycle are photosynthesis, respiration, combustion and decomposition. Photosynthesis is the process by which plants use light energy from the sun to convert carbon dioxide and water into glucose and oxygen. This is an important step in the carbon cycle as it removes carbon dioxide from the atmosphere, allowing for its eventual sequestration in long-term reservoirs such as fossil fuels. Respiration is the release of carbon dioxide back into the atmosphere due to both human activities like burning of fossil fuels and animals respiring to get energy from glucose in plants or oxygen from the air. Combustion involves burning fossil fuels such that carbon dioxide is released into the atmosphere, adding to the greenhouse gas effect. Decomposition is the process by which organic matter such as plants, animals and their waste are broken down into simpler molecules. This process releases carbon dioxide back into the atmosphere, offsetting some of the effects of photosynthesis.