How do humans add to the carbon dioxide in the atmosphere?
• Human beings, as part of their metabolism, exhale carbon dioxide into the atmosphere which accounts for only a small portion of carbon dioxide emissions. The main source of addition is the burning of fossil fuels – namely oil, coal, and natural gas. All of these components are rich in hydrocarbons that, upon combustion, release large quantities of carbon dioxide into the atmosphere. • Oil, coal, and natural gas are the major power sources in the United States today. They fuel our cars, provide material for our power plants to produce electricity, and heat our homes in the winters. It is estimated that the United States outputs 22 tons of carbon dioxide into the atmosphere per person per year! • This trend towards use of fossil fuels is found in many industrialized nations, however some have looked to alternative sources or increased efficiency when using fossil fuels. France, for example, relies heavily on nuclear power to produce electricity instead of fossil fuels. Japan has worked