Kolcykling

Kolcykling, or the carbon cycle, refers to the set of processes by which carbon atoms are exchanged among the Earth’s major reservoirs: the atmosphere, biosphere (plants and animals), oceans, soils and sediments, and the rocks of the lithosphere. The cycle operates over a wide range of timescales, from daily photosynthesis and respiration to millions of years of rock weathering and burial.

Key reservoirs and fluxes: the atmosphere, oceans, terrestrial vegetation, soils, and carbonate rocks form interconnected systems that store and release carbon. Carbon moves between these reservoirs through processes such as photosynthesis, respiration, decay, and decomposition; exchange between air and water via gas transfer; ocean uptake and release of dissolved inorganic carbon; the formation and dissolution of carbonate minerals; weathering of rocks; and the burial or long-term storage of organic carbon in sediments. Volcanic and tectonic activity can release carbon back to the atmosphere from rocks.

Natural and human influences: the cycle is shaped by climate, ocean chemistry, and biological activity. Human activities, including burning fossil fuels, deforestation, and cement production, have altered the balance of fluxes, increasing atmospheric CO2 concentrations and changing the capacity of oceans and land to absorb carbon. These changes affect climate, weather patterns, and ecosystem functioning through feedback mechanisms.

Measurement and modeling: scientists track carbon in various reservoirs using atmospheric observations, ocean and soil measurements, and satellite data, often integrating them with carbon-cycle models to estimate fluxes, budgets, and future scenarios. Understanding kolcykling is central to assessing climate change risks and informing policy.