Outdoors CO₂ Level

How much CO₂ in outdoors air?

The monthly average measure at the Mauna Loa (Hawai) in June 2010 is 392 ppm (http://co2now.org/). At the Mauna Loa, measures are taken at an altitude of 11,179 feet, in the Pacific, sort of in the middle of nowhere like the locations of most indoor gardens. There are no vehicles heavy circulation and no fossil fuel burning industries in the vicinity. The ground level CO2 readings are generally higher by at least a few ppm. Students in a France high school at Gif-sur-Yvette measured daily levels varying between 400 and 550 ppm in a field surrounded by trees from October 6 to December 19, 2007 (http://www.svt.ac-versailles.fr/spip.php?article171).

The CO₂ concentration is measured continuously in many locations in the Salt Lake City area (Utah, USA). Current daily concentration variations at the Rose Park Site can be seen at (http://co2.utah.edu/index.php?site=2&id=0&img=30) On July 20, 2010 levels varied over 24 hours from about 390 to about 500 ppm. About 11 AM, levels were 392.7, 418.0, 402.4 for sites at Rose Park, Sugar House and Murray respectively (http://co2.utah.edu/index.php?site=2&id=0&img=34). During January, past data at Murray (industrial area) have shown daily concentrations ranging from about 425 to 620 ppm. As can be shown from this data, CO₂ levels in outdoors'air vary widely over a 24 to 48 hours period. The outdoors' level also vary with the season, the presence of active vegetation and the surroundings CO2 rejects to atmosphere.