So is the Earth losing 50,000 tonnes per year of atmosphere?
“So is the Earth losing 50,000 tonnes per year of atmosphere?”
That is only an estimate for the amount of atmospheric mass being lost to space. The amount of atmospheric mass being lost and gained in exchanges of mass between the atmosphere, hydrosphere, cryosphere, biosphere, and lithosphere are highly variable over geological time periods. As the Sun grows larger as it enters the Red Giant phase of its life cycle, the Earth will be stripped of all but a trace remnant of its atmosphere and hydrosphere by the strong Solar Winds. Then the Earth’s lithosphere will begin to vaporize.