Long-term radiocarbon variation studies in the air and tree rings of Slovakia

Fifty-five years of radiocarbon variation studies are reviewed with an emphasis on a better understanding of the impacts of the Bohunice nuclear power plant and fossil fuel CO2 on the atmosphere and biosphere of Slovakia. The maximum Delta C-14 levels in the air up to about 1200 parts per thousand were observed during the 1970s at the & Zcaron;lkovce monitoring station, which after 2005 decreased to <30 parts per thousand. A relative decrease in the atmospheric Delta C-14 levels due to increasing levels of fossil CO2 in the atmosphere has also been significant, for example, in Bratislava down to about -330 parts per thousand, but after 2005 they were only <50 parts per thousand below the Jungfraujoch European clean-air level. The tree-ring data, averaging the annual Delta C-14 levels for several stations in Slovakia, have been in agreement with the atmospheric data, as well as with the newly established clean-air station at Jasn & aacute; in central Slovakia. Future C-14 levels will depend strongly on fossil CO2 levels in the atmosphere, which will change the bomb C-14 era to the fossil CO2 era. New investigations of C-14 variations in the atmosphere-biosphere-hydrosphere compartments represent a great challenge for radiocarbon science, important for better understanding of environmental processes, climate change, and impacts of human activities on the total environment. This new era of radiocarbon research will also need new developments in radiocarbon analytical technologies, as further progress in accuracy and precision of results (<1 parts per thousand) will be needed to meet the new radiocarbon challenges.