In addition, the researchers determined the ratio of two carbon isotopes in the samples. Isotopes are atoms of the same chemical element, which differ in the amount of the core building blocks and thus their mass. From the isotope ratio, the researchers deduce that carbon dioxide was not fixed by formation of new carbonate rock. This confirms the first finding: carbon dioxide dissolves almost exclusively in the pore water of the rock.
The industrial landfill of carbon dioxide in disused reservoirs is considered by climatologists as an option to delay greenhouse gas emissions. So far, however, it was unclear how the carbon dioxide reacts underground and whether it is safely disposed of there for a long time, without coming back to the earth's surface. The findings of geologists Gilfillan now show that carbon dioxide can remain dissolved in pore water for thousands to millions of years underground. The so-called carbon dioxide sequestration is however controversial among experts, because too little is known about the ecological effects. Critics see the necessary investment in alternative energy sources better invested, as the carbon dioxide in coal-fired power plants laboriously separate and then pump into gas deposits.Stuart Gilfillan (University of Manchester) et al: Nature (Vol. 458, p. 614) ddp / science.de? Martin Schäfer advertisement