You’ve probably heard that we need to curb carbon emissions. But do you know exactly where it is? Most of the carbon on Earth is stored in rocks and sediments. The rest are found in the ocean, the atmosphere, and some living organisms. Thanks to these reservoirs, carbon circulates through the Earth.
Carbon exchange and movement
Carbon moves through different mechanisms. For example, in the food chain, plants move carbon from the atmosphere to the biosphere through photosynthesis. They use energy from the sun to combine carbon dioxide with hydrogen and oxygen from water to create sugar molecules. The animals that eat these plants digest the sugar molecules for energy in their bodies. Likewise, respiration, excrement and the decomposition of faeces release carbon back into the atmosphere or into the soil, thus continuing the cycle.
The ocean is also essential in the movement of carbon, since it contains about 50 times more carbon than the atmosphere. Bidirectional carbon exchange can occur between the shallower ocean waters and the atmosphere. However, this is usually stored for centuries in the depths of the ocean.
On the other hand, rocks and fossil fuels (like coal and oil) contain carbon from plants and animals that lived millions of years ago. When these organisms died, various geological processes trapped their carbon and transformed it into carbon. Furthermore, processes such as erosion release this carbon very slowly, whereas volcanic activity tends to release it quickly.
Likewise, the burning of fossil fuels (caused by cars and power plants, among others) also causes carbon to reach the atmosphere quickly.
Carbon and human activity
Human activity has a tremendous impact on the carbon cycle. The burning of fossil fuels and the use of limestone to make concrete transfer a considerable amount of carbon to the atmosphere. Because of this, the amount of carbon dioxide in the atmosphere increases rapidly.
In addition, the ocean absorbs most of the carbon dioxide that is released from the burning of fossil fuels. This excess carbon dioxide is lowering the ocean’s pH through a process called acidification. The acidification of the seas and oceans, unfortunately, interferes with the life of some marine organisms such as corals, crabs or snails.
