The carbon cycle is the biogeochemical cycle by which carbon is exchanged among the biosphere, pedosphere, geosphere, hydrosphere, and atmosphere of the Earth.

The carbon cycle is thought of including the following major reservoirs of carbon: the atmosphere, the terrestrial biosphere, the oceans, the sediments and the Earth's interior.

The carbon cycle is one of the most important cycles of the Earth and allows for carbon to be recycled and reused throughout the biosphere and all of its organisms.

碳循環是一個生物地質化學循環圈，碳通過此循環在生物圈、土壤圈、地層、水圈、大氣中交流。

碳循環一般包括以下幾個主要的碳儲藏所：大氣、陸地生物圈、海洋、沉積物以及地球內部。

碳循環是地球最重要的循環之一，它使碳在整個生物圈及其所有有機體中得到循環和重復利用。