February 11, 2002—Scientists at the National Institute of Standards and Technology (NIST) and Arizona State University (ASU) have new, statistical evidence of the impact of human activity on rising levels of carbon dioxide in the atmosphere. Kevin J. Coakley of NIST and Randall S. Cerveny of ASU performed a statistical study of atmospheric concentrations of carbon dioxide (CO2) at the Mauna Loa Observatory in Hawaii and at the Amundsen-Scott Station at the South Pole. Their data study goes back to 1974 and 1975, respectively.
The researchers detected a seven-day cycle in carbon dioxide concentrations in Hawaii but not at the South Pole. On average, they found the highest CO2 concentrations in Hawaii were during weekdays and the lowest were during weekends. They attributed the apparently weekly cycle to air pollution emitted from either local traffic or transported to the observatory from more distant sources by winds.
“A weekly cycle in atmospheric CO2 records cannot be explained by natural variability. However, such a cycle can be attributed to human causes since the five-day workweek is an artifact of Western civilization,” Coakley and Cerveny said.
A paper based on the Coakley and Cerveny study will appear in an upcoming issue of Geophysical Review Letters. For more information, contact NIST.
