EN
The results of regular observations of atmospheric CO2 mixing ratios, carried out during the period 1996-2006 at two continental sites located in southern Poland, approximately 100 km apart, are presented and discussed. These sites (Kasprowy Wierch, 49°14'N, 19°59'E, 1989 m a.s.l. and Kraków, 50°04'N, 19°55'E, 220 m a.s.l) are located in two contrasting environments: (i) high-altitude mountainous area, relatively free of anthropogenic influences, and (ii) typical urban environment with numerous local sources of carbon dioxide of anthropogenic origin. The mean annual CO2 concentration recorded at Kasprowy Wierch increased from 361.8 ppm in 1997 to 382.7 ppm in 2006. The resulting mean annual growth rate (2.14±0.57 ppm year-1) is slightly higher than that derived for the marine CO2 reference curve (2.02±0.26 ppm year-1), calculated for the latitude band within which Kasprowy Wierch station is located (48.6°N-53.1°N). The CO2 mixing ratios measured in the urban atmosphere revealed quasi-permanent excess concentration of this gas when compared with the regional reference. The mean concentration of CO2 in Kraków for the period 2003-06 was ca. 8.5% higher than that recorded at the high-altitude mountain site (Kasprowy Wierch).