kolefnishringrásarinnar

Kolefnishringrásarinnar, or the carbon cycle, is the biogeochemical cycle by which carbon is exchanged among the biosphere, pedosphere, geosphere, hydrosphere, and atmosphere of the Earth. This cycle is crucial for life as it provides the building blocks for organic molecules and influences Earth's climate.

The carbon cycle can be broadly divided into two parts: the biological carbon cycle and the geological carbon cycle. The biological carbon cycle involves the exchange of carbon between living organisms and the atmosphere. Plants absorb carbon dioxide from the atmosphere through photosynthesis, converting it into organic compounds. Animals obtain carbon by consuming plants or other animals. Respiration by both plants and animals releases carbon dioxide back into the atmosphere. Decomposition of dead organic matter also returns carbon to the soil and atmosphere.

The geological carbon cycle operates over much longer timescales, involving processes like rock formation and volcanic activity. Carbon is stored in rocks and fossil fuels over millions of years. Subduction of tectonic plates can carry carbon-rich sediments deep into the Earth's mantle. Volcanic eruptions and the weathering of rocks release this carbon back into the atmosphere and oceans.

Human activities, particularly the burning of fossil fuels and deforestation, have significantly altered the natural carbon cycle. This has led to an increase in atmospheric carbon dioxide concentrations, contributing to global warming and climate change. Understanding and managing the carbon cycle is therefore essential for addressing these environmental challenges.