Kulstofkredsløb

Kulstofkredsløb refers to the biogeochemical cycle by which carbon is exchanged among the biosphere, pedosphere, geosphere, hydrosphere, and atmosphere of the Earth. It is one of the most important biogeochemical cycles. The Earth's carbon cycle is a process that continuously moves carbon from the atmosphere to the Earth and then back again. Carbon is essential to life on Earth. It is a major component of organic compounds and is also found in the Earth's crust, oceans, and atmosphere.

The carbon cycle involves several key processes. Photosynthesis is the process by which plants, algae, and cyanobacteria use sunlight, water, and carbon dioxide to create oxygen and energy in the form of sugar. Respiration is the process by which organisms release energy from food, consuming oxygen and releasing carbon dioxide. Decomposition is the breakdown of dead organic matter by bacteria and fungi, which releases carbon back into the atmosphere and soil. Combustion, such as the burning of fossil fuels and biomass, releases large amounts of carbon dioxide into the atmosphere.

The oceans play a significant role in the carbon cycle, absorbing and releasing carbon dioxide. Marine organisms also utilize carbon in various forms. Over geological timescales, carbon is stored in rocks and fossil fuels, forming the geosphere's carbon reservoirs. Human activities, particularly the burning of fossil fuels and deforestation, have significantly altered the natural balance of the carbon cycle, leading to increased atmospheric carbon dioxide concentrations and contributing to climate change. Understanding the carbon cycle is crucial for addressing environmental challenges and managing Earth's resources sustainably.