Photosynthesis is vital to the existence of life on earth. It is the process by which plants produce chemical or organic life energy from light energy. It is the source for all food and most oxygen.
The "photo" in photosynthesis is derived from the Greek word phos, meaning light---hence, photosynthesis is "synthesis with light."
Plants and some bacteria capture the sun's light energy to drive complex chemical reactions that convert carbon dioxide and water into organic compounds---carbohydrate foods and other fixed carbons such as coal and sediments. Oxygen is a waste byproduct.
Animals depend on the oxygen pumped into air by plants, while plants depend upon the carbon dioxide that animals exhale. According to National Geographic, half of the world's oxygen is produced from photosynthesis of oceanic phytoplankton, while the other half is produced from land plants.
The carbon-based glucose sugars that plants produce in photosynthesis are the origin of all food that animals depend upon in a complex ecosystem.
Photosynthesis withdraws carbon dioxide from the atmosphere, which is otherwise a toxic greenhouse gas at too high levels. The Woods Hole Research Center observes an increase of carbon into the earth's atmosphere in relation to land use---burning of fixed-carbon fossil fuels and carbon released from trees in deforestation.
- Woods Hole Research Center; Understanding the Global Carbon Cycle
- National Geographic News; Source of Half Earth's Oxygen Gets Little Credit
- "Molecular Mechanisms of Photosynthesis;" Robert E. Blankenship; 2002
photosynthesis, carbon dioxide, benefit of photosynthesis