The Most Important Biological Process

• Photosynthesis harvests energy from the sun, liberates oxygen and consumes carbon dioxide. All of the oxygen in the atmosphere comes from photosynthesis. Directly or indirectly, the process produces all food, fiber and building materials. Vegetation controls global climate through photosynthesis; thus, understanding how photosynthesis is involved in greenhouse gases is critical.
  
  

Photosynthesis and the Carbon Cycle

• Carbon is the fourth most abundant element after hydrogen, helium and oxygen. All organic substances, from fossil fuels to DNA, are bound to carbon. Carbon cycles through the land, ocean, atmosphere and the interior of the Earth. Photosynthesis is the component part of the carbon cycle on land, in the ocean and in the atmosphere.
  
  

Old-Growth Forests and Vegetation

• According to a study conducted by international scientists and published in the journal Nature in 2008, old-growth forests located in the Northern Hemisphere are responsible for at least 10 percent of global carbon uptake from the atmosphere. These forests, also known as carbon sinks, have accumulated carbon by photosynthesis for centuries. If destroyed, their carbon would be lost to the atmosphere.