Technical Note: Estimation of global loss of freshwater based on sea level changes over geological time

Abstract. Water vapour at the upper layer of the atmosphere undergoes light-dependent photolysis generating reactive hydrogen ions in statu nascendi that escape to space by different mechanisms. Besides hydrogen, other volatile gases such as methane molecules and helium atoms also escape to space in smaller quantities or traces such as oxygen. The escape of hydrogen through the planetary air leak cannot be reliably judged. Our estimation of global freshwater loss used another approach based on the sea-level changes that continuously fluctuated over geological time. The most reliable evidence for eustatic sea-level changes was provided by geologists estimating the shifts of shorelines generating sedimentary deposits. The sea-level changes turned to volumetric used data of a) radii of the Earth (r1) to calculate the volume of the geoid Earth (V1) comparing and validating them with available estimations, b) average sea depth (r2) comparing volumetric values of the sea with best-fitting values (V2). c) showing the correlation between geological changes (r3) and corresponding sea volumes (V3). These data, along with the sea volume of the infant Earth, allowed to plot a calibration curve to calculate the sea level belonging to the volume and vice versa. Geologic data indicate the shrinkage of freshwater pools during interglacial dilution periods and the remarkable long-term salination of the ocean.