Carbon Cycle. Carbon. Carbon exists in the nonliving environment as: Carbon dioxide (CO2) Carbonic acid ( HCO 3 − ) Carbonate rocks (limestone and coral = CaCO 3 ) Deposits of Fossil fuels Dead organic matter. Organic Carbon. Hydrocarbons: CH 4 Carbohydrate: CH 2 O.
Carbon exists in the nonliving environment as:
Mandale Limestone Quarry
CH4 + 2 O2 CO2 + 2 H2O + energy
Burning fossil fuels have serious impact on the carbon cycle.
86% of global primary energy consumption is fossil fuels.
Pre-Industrial value: 280 ppm (600 billion tons)
Current value: 380 ppm (800 billion tons)
Critical value: 560 ppm (1200 billion tons)