Radiocarbon method in environmental monitoring of CO2 emission

New results of carbon isotopic composition from tree rings have been analyzed. Δ14C and δ13C data, representing the isotopic composition of carbon in “clean air”, were obtained from annual rings of a pine tree (Pinus sylvestris) taken in the Niepołomice area, 25 km east Kraków, Poland. All samples were processed to extract α-cellulose, and the radiocarbon concentration in each annual ring was measured using AMS at the University of Nagoya. Stable isotopic composition of carbon was determined using isotope ratio mass spectrometry. The dataset covers the growth period between 1960 and 2003. The average difference between radiocarbon concentrations in Niepołomice and the North Hemisphere zone 1 (NH zone 1) for the period between 1960 and 1999 is 3.5 ± 1.6‰. These data are compared with previously presented results from the city of Kraków, where a local decrease in 14C concentration was observed due to local CO2 emission from fossil fuel use. The differences in observed 14C concentrations were used to estimate a magnitude of the local Suess effect in Kraków. Based on mass balance equations for CO214C concentrations, it was possible to calculate the CO2 concentration associated with fossil fuel emission (Cfoss) into the atmosphere. The highest values of Cfoss were recorded in the years 1986 (11.9 ± 1.4 ppm V) and 1983 (8.1 ± 1.3 ppm V), while the lowest value of 0.6 ± 1.8 ppm V was recorded in 2001.