Air quality is crucial for human health and welfare. A large number of studies have indicated strong associations between ambient air pollution levels and adverse health effects. There is a considerable number of literature reports concerning changes in atmospheric greenhouse emissions, while relatively little is known on changes in atmospheric CO emissions. This paper presents the rate of changes in atmospheric CO emissions using the logarithmic method in the assessment of this rate. Studies were conducted based on source data from 32 Organization for Economic Cooperation and Development countries. Analyses covered the period of 2005–2012. It was found that the average rate of changes had a negative average rate for most, although not all analyzed countries. In three of the 32 countries atmospheric CO emissions increased in that period. While the intensity of these changes varied, a defi nite majority of the countries reduced their CO emissions, whereas Turkey, Poland and Estonia increased their emissions.