Isotopically light carbon dioxide in nitrogen rich gases: the gas distribution pattern in the French Massif Central, the Eifel and the western Eger Rift

Based on characteristics of the distribution pattern of the western Eger Rift spring gases, a distribution pattern is presented for the gases of the French Massif Central. The central parts of these areas with ascending magmatic CO2 are characterised by high gas fluxes, high CO2 contents of up to 99.99 vol% and isotopially heavy CO2. In the peripheries, the decrease of d13C values of CO2 and CO2 contents in the gas phase is compensated by a rise in N2 contents. It can be demonstrated that gas fractionation in contrary to mixtures with isotopically light biogenic or crustal CO2 controls the distribution pattern of gas composition and isotopic composition of CO2 in these spring gases. Dissolution of CO2 results in formation of HCO3 – causing isotope fractionation of CO2 and an enrichment of N2 in the gas phase. With multiple equilibrations, values of about –17 ‰ or lower are obtained. The scale of gas alteration depends on the gas flux and the gas-water ratios respectively and can result in N2-rich gases. Essential for the interpretation are gas flux measurements with mass balances derived for most of the springs. Without such mass balances it is not possible to discriminate between mixture and fractionation. The processes of isotopic and chemical solubility fractionations evidently control the gas distribution pattern in other regions as well

Germany and Namibia as co-leads for the United Nations: chances and challenges on the road to the 2024 UN Summit of the Future

The President of the United Nations General Assembly has appointed the German and Namibian permanent representatives as co-facilitators for the Summit of the Future. The summit is scheduled for September 2024. Its aim is to reinforce the UN and global governance structures to better address old and new challenges. That includes making progress on implementing the sustainable development goals (SDGs) by 2030. Given the current geopolitical tensions, this will be no easy task. At this juncture it is im­por­tant to get the process off to a good start in order to gather support, generate atten­tion and engender confidence. (author's abstract