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 Δ¹⁴C levels in the air up to about 1200‰ were observed during the 1970s at the Žlkovce monitoring station, which after 2005 decreased to <30‰. A relative decrease in the atmospheric Δ¹⁴C levels due to increasing levels of fossil CO₂ in the atmosphere has also been significant, for example, in Bratislava down to about -330‰, but after 2005 they were only <50‰ below the Jungfraujoch European clean-air level. The tree-ring data, averaging the annual Δ¹⁴C 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 Jasná in central Slovakia. Future ¹⁴C levels will depend strongly on fossil CO₂ levels in the atmosphere, which will change the bomb ¹⁴C era to the fossil CO₂ era. New investigations of ¹⁴C 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‰) will be needed to meet the new radiocarbon challenges.