Main chemical reactions carried out in this cycle
There are many chemical reactions that are involved in the carbon cycle. Anything from giving birth, breathing, dying, lighting a match involves carbon & is able to significantly impact life on earth.
One chemical reaction we are all familiar with is cellular respiration, in which oxygen is used to break down carbohydrates which then results to energy, CO2, & H2O.
C6H12O6 (organic matter) + 6O2
⇒
6CO2 + 6H2O + energy
Another chemical reaction is called photosynthesis. Through this process, plants use solar energy to turn atmospheric carbon dioxide into carbohydrates (sugars). Organisms use these carbohydrates through the process of respiration (mentioned above).
Energy (sunlight) + 6CO2 + H2O
⇒
C6H12O6 + 6O2
During photosynthesis, plants use carbon dioxide and produce oxygen.
During metabolism oxygen is used and carbon dioxide is a product.
Humans impact the carbon cycle during the combustion of any type of fossil fuel, which may include oil, coal, or natural gas. The carbon is said to be "fixed" in place and is essentially locked out of the natural carbon cycle. Humans intervene during by burning the fossil fuels. During combustion in the presence of air (oxygen), carbon dioxide and water molecules are released into the atmosphere.
Causes and effects of the increasing concentration of CO2 in the atmosphere.
The main worry is that, as previously mentioned, the amount of radiation which escapes depends on the concentration of greenhouses gases in the atmosphere - carbon emissions add to the concentration, meaning that less radiation escapes. This means that the surface temperature of the Earth increases - by 0.6°C ± 0.2°C over the last century. This may not sound like much, but the warming will increase with time, and could have disastrous consequences. These might include:
• Sea level rise - densely settled coastal plains would become uninhabitable with just a small rise in sea level, which would result from melting of the ice caps
• Impacts on agriculture – Global warming could have major effects on agricultural productivity
• Reduction of the ozone layer - Warming would result in increased high cloud cover in winter, giving chemical reactions a platform in the atmosphere, which could result in depletion of the ozone layer
• Increased extreme weather - A warmer climate could change the weather systems of the earth, meaning there would be more droughts and floods, and more frequent and stronger storms
• Spread of diseases - Diseases would be able to spread to areas which were previously too cold for them to survive in
• Ecosystem change - As with the diseases, the range of plants and animals would change, with the net effect of most organisms moving towards the North and South Poles