Combustion Releases Carbon Dioxide into the Atmosphere
- When biomass, peat, coal, oil, or natural gas are burned, carbon dioxide ($CO_2$) is released into the atmosphere.
- This process is called combustion, a chemical reaction where carbon compounds react with oxygen to produce $CO_2$ and water, releasing energy as heat and light.
Combustion of Biomass
- Biomass includes organic materials like wood, crop residues, and animal waste.
- When burned, the carbon stored in biomass is released as $CO_2$.
- Unlike fossil fuels, biomass is part of the short-term carbon cycle because it absorbs $CO_2$ during growth, which is then released during combustion.
Burning wood in a fireplace releases $CO_2$, but this carbon was recently absorbed by the tree during photosynthesis.
Combustion of Peat
- Peat forms in waterlogged environments where decomposition is slow due to anaerobic and acidic conditions.
- Over thousands of years, partially decomposed plant material accumulates as peat, storing carbon.
- When peat is drained and dried for fuel, it combusts, releasing $CO_2$.
Peatlands are significant carbon sinks, storing twice as much carbon as all the world’s forests combined.
Combustion of Fossil Fuels: Coal, Oil, and Natural Gas
- Fossil fuels are ancient carbon sinks formed over millions of years from decomposed organic matter buried under sediment.
- Under high pressure and temperature, this material transformed into coal, oil, and natural gas.
- Burning these fuels releases carbon that has been sequestered for millions of years, adding to atmospheric $CO_2$ levels.
- Think of fossil fuels as a savings account of carbon.
- Burning them is like withdrawing money that has been saved for millions of years, but without any plan to replenish it.
