Carbon dioxide (CO₂) is one of the very few carbon containing inorganic compounds found in nature. It is the most ubiquitous greenhouse trace gas. Photoautotrophs fix CO2, in a process called photosynthesis, into organic energy forms essential to the c hemoheterotrophs on this planet. However, there may be disadvantages in releasing large quantities of CO2 into the atmosphere, due to its ability to absorb infrared radiation emitted from the Earth.

It has been estimated that 50% to 60% of the anthropogenic greenhouse effect is attributed to this gas. In order to conceptualize our place in the life series of Earth, ice core data from Antarctica indicates CO2 levels ranged from 200 to 300 ppm over the last 160,000 yrs. prior to the industrial revolution. Since 1860 the concentration of CO2 has grow exponentially (Botkin and Keller, 1995).

Continuous measurements of atmospheric CO₂ have been made at the Mauna Loa Observatory since 1958 by Scripps Institution of Oceanography. This data demonstrates an upward trend in CO2 levels with seasonal decreases during summer months and increases dur ing winter months (Boden, Kanciruk, and Farrell, 1990).

Questions:

• What are anthropogenic sources?
• What is the difference between organic and inorganic molecules.
• Describe the differences between autotrophs and heterotrophs. Give examples of each.
• Given that the current data indicates a 0.5% increase in CO2 concentrations per year, how many years will pass before the current levels double?
• What are the major causes of increased atmospheric CO2 levels?
• What can you do to decrease these atmospheric levels?
• It is estimated that the CO2 produced annually is much greater than the amount of increase, what is happening to the CO2 unaccounted for?
• What might be causing the seasonal swings in atmospheric CO2 levels observed at the Mauna Loa Observatory?
• What effect might deforestation have on atmospheric CO2 levels?
• What effect might burning Coal have on atmospheric CO2 levels?
• Is there any energy source that might not effect atmospheric CO2 levels?

• Mauna Lao carbon dioxide concentractions, 1958-1993.
• Mauna Lao Observatory (NOAAA)
• Carbon Dioxide Information Analysis Center