I’ve been turning over ideas for a Mars-global artificial magnetic field for a few months now. If we want to make the planet truly habitable we need to warm it up, but without a magnetic field the solar wind would simply strip it away at a faster rate as heat expansion made the atmosphere larger.
Any global field would require a lot of energy due to the flux, but it wouldn’t have to be very strong at any one point (although I’ve been mulling the benefits of large distributed infrastructure that produce weak fields over a large area vs. large numbers of small infrastructure elements that each produce very strong fields in a small area).
We don’t need a global magnetic field on Mars to establish an outpost, but if we plan to have humans stay there forever, then we do need one. The technology isn’t new by any stretch, but we’ll need to establish real manufacturing on Mars to make it happen.
This was exactly the idea that I had thought of several years ago when I first heard of the solar wind stripping Mars' atmosphere. Build a whole lot of magnet stations all over Mars, and let their fields sum together. I have to admit I didn't think of the Lagrange point idea. That sounds like a possibly better approach.
I am pleased to see people are thinking along the same lines.
On another Mars related issue, should Phobos be boosted up to rendezvous with Deimos, or should it be crashed into the planet to add more mass?
A single moon would help stabilize Mars, but Mars could always use more mass.