Those climate models of which Mr. Gregory speaks estimate a global water loss to outer space to be approximately 26,000 litres per day. This estimated, daily ionic outflow is based on data from satellite STEREO-B during its one and only observations of Earth's gas/electromagnetic 'tail' during a Solar minima in February of 2007.
That single observation, taken when the sun was weak is continually used for reference today even though we know that there are linear correlations between the cyclic solar wind magnetic flux, the rate of oxygen/hydrogen ion flow out of Earth's atmosphere and Earth's weakening magnetic field strength. (LINK),
Masatoshi Yamauchi of the Swedish Institute of Space Sciences has, through more recent satellite data observed a very great difference in atmospheric loss to space between typical solar minimum and solar maximum periods.
He writes that current (2019) “statistics of the solar energy flux, solar wind, and Kp dependences of these O+ outflows in these regions show that solar wind dynamic pressure, solar wind coupling function, and Kp are the most influencing parameters, with 1.5 orders of magnitude difference between quiet and active cases.” (LINK),
Here is an excellent power-point presentation from the European Space Agency on water loss, solar flux and the influence of a planetary magnetic field; (LINK)
Solar wind & atmospheric stripping. Multi-disciplinary study: (LINK),
Science currently associates the lack of water on the planets Mars and Venus with their lack of a magnetic field. Earth's magnetic field, which they believe keeps our atmosphere in place has been weakening since a catastrophic solar flare hit us in 1859 (Carrington event), energizing our atmosphere so severely that the Aurora Borealis was visible over the island of Cuba. (LINK), (LINK),
We know our field began weakening at that point in time because magnetometers have been in use to measure and record Earth's 'magnetic strength' since their invention in 1833. (LINK), (LINK), (LINK), (LINK),
What science cannot agree on is the rate at which our magnetic field is weakening, or at least there is an argument on paper. Since the introduction of electronics and the advent of satellite technology to the study of our field we have very accurate, real time data on its strength and morphology but NASA and other agencies appear loathe to release it.
Mainstream Science says that the rate of weakening is between 6% and 10% per century. However other scientists relying on information from independent magnetometers and satellite data generated by people and institutions free of political influence believe the field to be weakening at 10% per decade (10x faster), plus the rate of decrease accelerating, albeit not in a linear fashion.
Why does this matter? How is the weakening magnetic field related to increased atmospheric 'loss'?
Janet Luhmann of UC Berkeley Space Sciences Lab in her 2007 presentation, 'Solar History Effects on Venus and Earth Climate' illustrates how the Sun becomes more influential on atmospheric ion outflow as a planets magnetic field weakens. Her works shows that, “As Earth loses the protection of her magnetic field, solar wind particles (mostly protons) directly deposit energy in areas of atmospheres unprotected by magnetic fields. They also Ionize planetary neutrals via charge exchange and electron impact. In addition, the solar wind electric field accelerates planetary ions.
Recent efforts by Kulikov, et al., 2006, 2007 and Lammer, et al. 2006 incorporate the results of past observational efforts relating to solar effects toward climate and upper atmospheric modeling efforts. Their work adds new calculations and simulations to evaluate the role of the upper atmosphere changes and escape to space in the evolution of the atmospheres of Venus, Earth, and Mars.” (LINK),
According to Janet Luhmann Earth should be drying at a rate commensurate with our field strength loss. That means Ken Gregory should continue to see less atmospheric moisture and it means that our world should continue to see greater and greater temperature extremes. (LINK),
Why the temperature extremes?
Applying the laws of physics and some historical examples one finds that the lack of water in an atmosphere removes its 'thermal flywheel' governing global atmospheric conditions. Without sufficient water to buffer the absorption and release of heat energy in the atmosphere our climate will begin to swing more rapidly between greater extremes of hot and cold. Effects of solar energy injected into our magnetosphere and atmosphere will become stronger and more localized than they have been, creating opposite temperature extremes within close proximity to one another over land and water that will generate increasingly high wind velocities between them. (LINK), (LINK), (LINK), (LINK), (LINK), (LINK),