Carbon Cycle - GCSE Biology Definition

The carbon cycle is the natural process by which carbon moves between the atmosphere, living organisms, oceans, and the Earth’s crust. Plants take in carbon dioxide (CO₂) from the air during photosynthesis to make glucose. Animals consume plants, and carbon becomes part of their bodies. Both plants and animals release carbon dioxide back into the atmosphere during respiration. When organisms die, decomposers break down their remains, releasing carbon back into the soil and air. Some carbon may become trapped in rocks or fossil fuels over millions of years. Human activities, such as burning fossil fuels and deforestation, increase atmospheric carbon dioxide, which contributes to climate change. Understanding the carbon cycle is important in GCSE Biology for studying ecosystems and global warming.