Hi

Your point is clear but he's obviously thought a lot and did some BOTE calculations of his own. He just happened to be seriously off - probably assumed a 2000 K atmosphere at SURFACE pressure, rather than exosphere. Or some other simple error. The physics is inescapeable - 10 years is absurd. Solar wind dissociative recombination of the N2 into N atoms is the fastest loss process and it takes billennia. Bulk hydrodynamic escape of light gas species is another "fast" process but it takes billennia too - and far longer for heavier gases dragged along by escaping H, He.

Terraforming Mars with an atmosphere that will last > 10^6 years is still a safe idea. With the right mix of high atmosphere trace gases exospheric heating can be reduced to the current 300 K on Mars instead of Earth's ~ 1000 - 2000 K and the atmosphere would keep even longer.

Adam