How much carbon does human respiration, digestion etc. contribute to global warming?
Actually, this shows that you are thinking about the topic of global warming, and that is good. Human respiration is “carbon neutral” meaning that it does not change the overall carbon dioxide content of the atmosphere. How can that be with over 6 and a half billion people? The carbon dioxide we breathe out comes from breaking down molecules of our food to get the energy. The food molecules trace back through short food chains to producers or autotrophs that made food by photosynthesis. These producers took carbon dioxide from the air. This is called the short-term carbon cycle. Carbon dioxide comes out of the air into producers, consumers eat the carbon compounds and return the carbon dioxide to the air. Think of having a bathtub full almost to the point of spilling over. The short term carbon cycle could be represented by dipping out a cup of water (plants), pouring the water into a bowl (animals eat the plants), and pouring the water back into the tub from the bowl (breathing out ca
