Carbon Dioxide 101


There are both natural CO2 sources and man-made (anthropogenic) CO2 sources.


Natural CO2 sources account for the majority of CO2 released into the atmosphere. Oceans provide the greatest annual amount of CO2 of any natural or anthropogenic source. Other sources of natural CO2 include animal and plant respiration, decomposition of organic matter, forest fires, and emissions from volcanic eruptions. There are also naturally occurring CO2 deposits found in rock layers within the Earth’s crust that could serve as CO2 sources.


Anthropogenic CO2 sources are part of our everyday activities and include those from power generation, transportation, industrial sources, chemical production, petroleum production, and agricultural practices. Many of these source types burn fossil fuels (coal, oil, and natural gas), which are the leading cause of CO2 emissions. The map below depicts the more than 4,000 DOE identified stationary sources that emit over 3,000 million metric tons of anthropogenic CO2 per year. The largest emitter of anthropogenic CO2 is depicted in blue and represents the locations where electric power is generated.

Map depicting the stationary anthropogenic sources of CO2 by industry
in the United States and portions of Canada. (click to enlarge)

A breakdown of the major stationary source emissions depicted in the figure below provides a visual representation of the impact that power generation and, to a lesser degree, other industrial activities have on anthropogenic CO2 emissions.

Diagram depicting the stationary anthropogenic CO2 emissions by major industry.
The largest contributor to these emissions is from electricity production (73 percent).
(click to enlarge)  


Myth: Carbon dioxide comes only from anthropogenic sources, especially from the burning of fossil fuels.
Reality: Carbon dioxide comes from both natural and anthropogenic sources; natural sources are predominant.

Are the additional emissions of anthropogenic CO2 to the atmosphere impacting the climate and environment?