This isn't necessary. The rate at which atmosphere is stripped by solar wind is too slow for human time-scale to notice. Also the role in magnetic fields protecting against radiation is over stated. Most of that is physically blocked by the planet on one side of you and the atmosphere on the other.

Granted the atmosphere is thin, but the daily dose of radiation is fairly low. Most arguments depend on a lifetime dose being high. But that's a bit like claiming that I'll drown in the 10,000 gallons of water that I'll drink over the course of my life. Yes radiation damage does accumulate more that water, but our bodies do have repair mechanisms that make life-time dose nowhere near equivalent to a short term dose.