Photosynthesis

• The process of photosynthesis, also known as the carbon cycle is the respiration process used by plants to produce food for survival. Carbon dioxide is released into the atmosphere by natural processes, such as the release of carbon dioxide by animals. Plant respiration during the carbon cycle converts carbon dioxide into sugars, such as glucose used by the plant for survival and oxygen. The oxygen produced by plants during the carbon cycle is released into the atmosphere as a byproduct.
  
  

Carbon

• The carbon cycle is a process balanced naturally to maintain the amount of carbon in the earth's atmosphere to maintain some of the energy provided by the sun and allow the remainder of the sun's energy to be deflected into space. This balanced amount of carbon in the atmosphere has been affected by human actions since the use of fossil fuels began to increase during the industrial revolution of the 19th century, according to Columbia University. The amount of carbon dioxide in the atmosphere has increased from around 289 parts per million before the industrial revolution to over 360 parts per million in the 21st century. The increase in carbon dioxide has resulted in the greenhouse effect that has raised temperatures around the world.
  
  

Fuels

• Fossil fuels are the major impact of humans on the carbon cycle, these fuels are formed by the burying, compression and decay of plants and animals over thousands of years. The carbon contained within the decomposed organic material becomes fossil fuels, including coal, oil and natural gas that store carbon that would not normally become part of the carbon cycle. When humans mine and drill for fossil fuels the carbon within the fuels is burned for energy that releases large amounts of carbon dioxide into the atmosphere that cannot be consumed by plants in the carbon cycle.
  
  

Habitat

• The release of excess carbon into the atmosphere by human beings has had a detrimental effect on the habitat of plants, Columbia University reports. The heating of the atmosphere results in a rise in ocean temperatures raising sea levels through thermal expansion, this can destroy shoreline habitats for plants. Weed species of plants are also known to thrive with higher carbon dioxide levels in the atmosphere, leading to greater competition for survival between existing plant species and weeds.