Carbon cycle

The carbon cycle is the continuous movement of carbon between the atmosphere, living organisms, soil, and oceans. This planetary process is fundamental to life itself—without it, there would be no photosynthesis, no respiration, and no way for carbon to fuel the chemistry of existence.

Carbon moves through several interconnected pathways. Plants absorb CO₂ from the atmosphere during photosynthesis, converting it into organic compounds. When animals eat plants—or eat other animals—they consume this stored carbon. Both plants and animals release carbon back to the air through respiration. Dead organisms and waste decompose, with decomposers returning carbon to the soil and atmosphere. Meanwhile, ancient carbon locked in fossil fuels (coal, oil, gas) formed over millions of years, and burning these fuels releases that stored carbon rapidly.

The oceans play an enormous role, absorbing atmospheric CO₂ and storing it in marine organisms and deep sediments. This balance has remained relatively stable for millennia, but industrial activities have dramatically increased atmospheric carbon, accelerating the cycle and warming the planet.

Understanding the carbon cycle is essential to addressing climate change and designing sustainable systems.

Related

Photosynthesis, Greenhouse gases, Climate change, Fossil fuels, Nitrogen cycle, Decomposition