Hiilivedyn

Hiilivedyn is a term used in some scientific and educational contexts to describe the carbon dynamics within Earth's system, including how carbon moves among the atmosphere, oceans, land biosphere, soils, and sediments. The concept encompasses both natural processes and human-induced changes that affect the size and distribution of carbon reservoirs over time.

In the atmosphere, carbon is exchanged with land and ocean reservoirs through processes such as photosynthesis, respiration, decay, and carbonate chemistry in seawater. Plants and soils store carbon via photosynthesis and organic matter; soils contain large pools vulnerable to disturbance. The oceans absorb significant amounts of atmospheric CO2, affecting seawater chemistry and the carbon sink.

Human activities—burning fossil fuels, deforestation, and cement production—add large amounts of CO2 to the atmosphere, altering the natural carbon balance. Feedbacks, such as permafrost thaw and changes in vegetation, can amplify or dampen responses to emissions.

Models of hiilivedyn are used to estimate carbon budgets and predict climate change. These Earth system models integrate processes of the carbon cycle with climate dynamics and include uncertainty in processes like soil carbon turnover and oceanic uptake.

In policy and science communication, hiilivedyn helps frame discussions of mitigation and adaptation by explaining the persistence of emissions and potential for carbon sequestration in soils, forests, and oceans.