Photosynthesis removes carbon from the abiotic environment (fixes carbon into organic molecules) Carbon changes from food chain through consumption of one organism by an additional Cellular respiration, combustion, and abrasion of limestone get back carbon to the atmosphere, water and abiotic environment: The global carbon budget is the balance of the exchanges (incomes and losses) of carbon between the carbon reservoirs or between one specific loop (e.g., atmosphere ↔ biosphere) of the carbon cycle. An examination of the carbon budget of a pool or reservoir can give information regarding whether the pool or reservoir is functioning as a source or sink for carbon dioxide. The carbon cycle was initially discovered by Joseph Priestley and Antoine Lavoisier, and popularized by Humphry Dav.