What effect does burning fossil fuels have on the carbon cycle?

Burning fossil fuels has a significant impact on the carbon cycle, primarily by returning carbon dioxide to the atmosphere. Fossil fuels, such as coal, oil, and natural gas, are composed mainly of carbon that has been stored for millions of years underground. When these fuels are burned for energy, the carbon combines with oxygen in the atmosphere, resulting in the release of carbon dioxide—an important greenhouse gas that contributes to climate change. This process disrupts the natural carbon cycle, which normally involves the absorption of carbon dioxide by plants during photosynthesis and its eventual return to the atmosphere through respiration and decay. By increasing the concentration of carbon dioxide in the atmosphere, burning fossil fuels exacerbates the greenhouse effect and alters climate patterns.