The History of Atmospheric Carbon Dioxide on Earth
2010-01-19 from:planetforlife author:
The significance of carbon dioxide
Only one part in 2597 of Earth's atmosphere is carbon dioxide. Yet, plants make themselves from it. A very substantial oak tree is made from what seems like a few insubstantial air molecules. Plants use photosynthesis to make themselves from water, carbon dioxide and energy from the Sun. Atmospheric oxygen is a byproduct of photosynthesis. Animals reverse photosynthesis. They eat plants or they eat animals that eat plants. Animal metabolism consumes oxygen and releases carbon dioxide and water. The net effect of all this is a constant movement of carbon between plants, animals and the atmosphere.
Carbon dioxide and water vapor are the most important greenhouse gases. Without greenhouse gases, Earth would be an ice planet and there would be no life.
We humans, because of our numbers and our technology, greatly influence Earth's atmosphere. We need to understand what we are doing to Earth's atmosphere.
The recent history of atmospheric carbon dioxide
Charles Keeling began precise monthly measurements of the concentration of carbon dioxide in 1958. He was the first to do so systematically and so his data have come to be known as the "The Keeling Curve." Learn more about Charles Keeling at http://scrippsco2.ucsd.edu/home/index.php The measurements were made at the Mauna Loa Astronomical Observatory which is at the summit of an inactive volcano in Hawaii. Mauna Loa was chosen because it is far from major sources or sinks of carbon dioxide. Carbon dioxide concentrations measured at Mauna Loa are a good proxy for the average of the whole Earth.
The black wiggles are a continuous record of the concentration of carbon dioxide in the Earth's atmosphere from 1958 to May 2007. NOAA (National Oceanic & Atmospheric Administration, which is a branch of the U.S. Department of Commerce) is the original source of the data which may be found at http://www.esrl.noaa.gov/gmd/ccgg/trends/ This is data collected by competent scientists and it is not controversial.